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ASTROBIOLOGY AND THE SEARCH FOR LIFE 

BEYOND EARTH IN THE NEXT DECADE 

HEARING 

BEFORE THE

COMMITTEE ON SCIENCE, SPACE, AND 

TECHNOLOGY 

HOUSE OF REPRESENTATIVES 

ONE HUNDRED FOURTEENTH CONGRESS 

FIRST SESSION 

September 29, 2015 

Serial No. 114–40 

Printed for the use of the Committee on Science, Space, and Technology 

( 

Available via the World Wide Web: http://science.house.gov 
(II) 

COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY 

HON. LAMAR S. SMITH, Texas, Chair 

FRANK D. LUCAS, Oklahoma 

F. JAMES SENSENBRENNER, JR., 

Wisconsin 

DANA ROHRABACHER, California 

RANDY NEUGEBAUER, Texas 

MICHAEL T. MCCAUL, Texas 

MO BROOKS, Alabama 

RANDY HULTGREN, Illinois 

BILL POSEY, Florida 

THOMAS MASSIE, Kentucky 

JIM BRIDENSTINE, Oklahoma 

RANDY K. WEBER, Texas 

BILL JOHNSON, Ohio 

JOHN R. MOOLENAAR, Michigan 

STEPHEN KNIGHT, California 

BRIAN BABIN, Texas 

BRUCE WESTERMAN, Arkansas 

BARBARA COMSTOCK, Virginia 

GARY PALMER, Alabama 

BARRY LOUDERMILK, Georgia 

RALPH LEE ABRAHAM, Louisiana 

DARIN LAHOOD, Illinois 

EDDIE BERNICE JOHNSON, Texas 

ZOE LOFGREN, California 

DANIEL LIPINSKI, Illinois 

DONNA F. EDWARDS, Maryland 

SUZANNE BONAMICI, Oregon 

ERIC SWALWELL, California 

ALAN GRAYSON, Florida 

AMI BERA, California 

ELIZABETH H. ESTY, Connecticut 

MARC A. VEASEY, Texas 

KATHERINE M. CLARK, Massachusetts 

DON S. BEYER, JR., Virginia 

ED PERLMUTTER, Colorado 

PAUL TONKO, New York 

MARK TAKANO, California 

BILL FOSTER, Illinois 
(III) 

C O N T E N T S 

September 29, 2015 

Page 

Witness List ............................................................................................................. 2 

Hearing Charter ...................................................................................................... 3 

Opening Statements 

Statement by Representative Lamar S. Smith, Chairman, Committee on 

Science, Space, and Technology, U.S. House of Representatives ..................... 9 

Written Statement ............................................................................................ 10 

Statement by Representative Eddie Bernice Johnson, Ranking Member, Committee on Science, Space, and Technology, U.S. House of Representatives .... 11 

Written Statement ............................................................................................ 12 

Witnesses: 

Dr. Ellen Stofan, Chief Scientist, NASA 

Oral Statement ................................................................................................. 14 

Written Statement ............................................................................................ 17 

Dr. Jonathan Lunine, David D. Duncan Professor in the Physical Sciences, 

and Director, Center for Radiophysics and Space Research, Cornell University 

Oral Statement ................................................................................................. 22 

Written Statement ............................................................................................ 24 

Dr. Jacob Bean, Assistant Professor, Departments of Astronomy and Astrophysics, Geophysics, University of Chicago 

Oral Statement ................................................................................................. 30 

Written Statement ............................................................................................ 32 

Dr. Andrew Siemion, Director, SETI Research Center, University of California, Berkeley 

Oral Statement ................................................................................................. 37 

Written Statement ............................................................................................ 39 

Discussion ................................................................................................................. 50 

Appendix I: Answers to Post-Hearing Questions 

Dr. Ellen Stofan, Chief Scientist, NASA ................................................................ 72 

Dr. Jonathan Lunine, David D. Duncan Professor in the Physical Sciences, 

and Director, Center for Radiophysics and Space Research, Cornell University ......................................................................................................................... 87 

Dr. Jacob Bean, Assistant Professor, Departments of Astronomy and Astrophysics, Geophysics, University of Chicago ....................................................... 91 

Dr. Andrew Siemion, Director, SETI Research Center, University of California, Berkeley .................................................................................................... 95 

(1) 

ASTROBIOLOGY AND THE SEARCH FOR LIFE 

BEYOND EARTH IN THE NEXT DECADE 

TUESDAY, SEPTEMBER 29, 2015 

HOUSE OF REPRESENTATIVES, 

COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY, 

Washington, D.C. 

The Committee met, pursuant to call, at 10:02 a.m., in Room 

2318 of the Rayburn House Office Building, Hon. Lamar Smith 

[Chairman of the Committee] presiding. 
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Chairman SMITH. The Committee on Science, Space, and Technology will come to order. Without objection, the Chair is authorized to declare recesses of the Committee at any time. 

Welcome to today’s hearing, which is called ‘‘Astrobiology and the 

Search for Life beyond Earth in the Next Decade.’’ 

Let me make a couple of announcements. One is an explanation 

and that is to say that we expect more Members shortly, but at 

least on the Republican side, all of our Members are in a Republican conference that I left early in order to start on time here, but 

other Members will be arriving shortly. And the same may be true 

of our colleagues on the other side of the aisle as well. 

We have a new member of the Science, Space, and Technology 

Committee, and I would like to introduce him. He is Darin LaHood, 

the first Member to my left, whose father I served with in Congress 

some years ago. Darin LaHood represents a district in Illinois. He’s 

a former State Senator or serving as a State Senator when he was 

elected to Congress. Before that, he was both a State and Federal 

prosecutor. So we welcome his many talents to the Committee. He 

is going to be serving on two subcommittees, Research and Technology and Oversight, where he will be bringing all those legal 

skills to bear. And so we are pleased to have him join us today and 

permanently on this Committee. Welcome, Darin, to you. 

Mr. LAHOOD. Thank you, Mr. Chairman. 

Chairman SMITH. I’m going to recognize myself for an opening 

statement and then I’ll recognize the Ranking Member. 

Edwin Hubble once said: ‘‘Equipped with his five senses, man explores the universe around him and calls the adventure Science.’’ 

There are few greater adventures than the search for life beyond 

Earth. 

When the Hubble Space Telescope was launched in 1990, planets 

around other stars had not yet been discovered. The only planets 

we knew were those that orbited our Sun. Since 1995, however, 

when the first extrasolar planet was detected, the rate of discovery 

of new exoplanets and external solar systems has been truly remarkable. 

Today, with the Kepler Telescope, we have found nearly 2,000 

confirmed planets that orbit around other stars in our galaxy. Of 

these, 306 lie within the habitable zone of the stars they orbit— 

where water could exist—and 14 are almost the size of the Earth. 

Whether life exists beyond Earth, and if so, how humans can detect it, is a critical question. If definitive evidence of life is found, 

it may be the most significant scientific discovery in human history. The search for life in the universe is a priority of NASA and 

the U.S. scientific community. Seeking habitable planets is one of 

the three scientific objectives of the 2010 National Research Council Decadal Survey on astronomy and astrophysics. 

The United States pioneered the field of astrobiology and continues to lead the world in this type of research. Since the space 

program began, NASA has explored the cosmos for life beyond 

Earth and has conducted scientific research that investigates this 

possibility. 

NASA’s astrobiology program continues these scientific endeavors to improve our understanding of biological, planetary, and cosmic phenomena. Just yesterday, NASA announced that it identified 
10 

flowing briny water on Mars. This past April, NASA’s Chief Scientist, Dr. Ellen Stofan, made global headlines with her prediction 

that ‘‘we are going to have strong indications of life beyond Earth 

in the next decade and definitive evidence within the next 20 to 30 

years.’’ And I am glad that Dr. Stofan has joined us today. 

Within our solar system, the question of whether life exists or existed on Mars continues to capture the public imagination. In the 

past year, NASA’s Curiosity Rover made several major scientific 

discoveries relevant to the search for life on Mars. Curiosity measured a spike in levels of the organic chemical methane in the local 

atmosphere of its research site. It also detected other organic molecules in drill samples in a mudstone that once sat at the bottom 

of a lake. And Jupiter’s moon, Europa, shows strong evidence of an 

ocean of liquid water beneath its surface, which could host conditions favorable to some form of life. 

NASA selected nine science instruments for a future mission to 

Europa. Two of them are from the Southwest Research Institute in 

San Antonio and one from the University of Texas in Austin. These 

instruments will help scientists investigate the chemical makeup of 

Europa’s potentially habitable environment. 

Last July, astronomers, with the help of the Kepler Space Telescope, confirmed the discovery of Kepler 452-b, the first nearEarth-size planet in the ‘‘habitable zone’’ around a sun-like star. 

This discovery marks another milestone in the journey to find another ‘‘Earth.’’ 

The Transiting Exoplanet Survey Satellite, which will launch in 

2017, and the James Webb Space Telescope, which will begin in 

2018, will help scientists discover more planets with potential biosignatures in their atmospheres, such as evidence of oxygen and 

methane gas. Around the world a relatively small number of astronomers monitor radio and optical emissions throughout the universe. They try to filter out the cosmic noise and interference of 

satellites and spacecraft to find anomalies that could represent life. 

The search for life beyond Earth also inspires a new generation 

of explorers. It motivates students to study math, science, engineering, and computer science. Just a few months ago, astronomers 

confirmed that Tom Wagg, a 15-year-old student, discovered 

exoplanet WASP–142b, which orbits a star approximately 1,000 

light years away in the constellation Hydra. 

It is in our human nature to seek out the unknown and to discover the universe around us. The stars compel us to look upward 

and lead us from this world to another. Many Americans often gaze 

into the beauty of the night sky in awe; some may wonder if there 

is life beyond our pale blue dot. 

I thank our witnesses and look forward to hearing their testimony and particularly about recent developments in the field of 

astrobiology and the search for life. 

[The prepared statement of Chairman Smith follows:] 

PREPARED STATEMENT OF COMMITTEE CHAIRMAN LAMAR S. SMITH

Edwin Hubble once said: ‘‘Equipped with his five senses, man explores the universe around him and calls the adventure Science.’’ There are few greater adventures than the search for life beyond Earth. 
11 

When the Hubble Space Telescope was launched in 1990, planets around other 

stars had not yet been discovered. The only planets we knew were those that orbited 

our Sun. 

Since 1995, however, when the first extrasolar planet was detected, the rate of 

discovery of new exoplanets and external solar systems has been truly remarkable. 

Today, with the Kepler Telescope, we have found nearly 2000 confirmed planets 

that orbit around other stars in our galaxy. Of these, 306 lie within the habitable 

zone of the stars they orbit-where water could exist-and 14 are almost the size of 

Earth. 

Whether life exists beyond Earth, and if so, how humans can detect it, is a critical 

question. If definitive evidence of life is found, it may be the most significant scientific discovery in human history. 

The search for life in the Universe is a priority of NASA and the U.S. scientific 

community. Seeking habitable planets is one of the three scientific objectives of the 

2010 National Research Council decadal survey on astronomy and astrophysics. 

The United States pioneered the field of astrobiology and continues to lead the 

world in this type of research. Since the space program began, NASA has explored 

the cosmos for life beyond Earth and has conducted scientific research that investigates this possibility. 

NASA’s astrobiology program continues these scientific endeavors to improve our 

understanding of biological, planetary, and cosmic phenomena. Just yesterday, 

NASA announced that it identified flowing briny water on Mars. 

This past April, NASA’s Chief Scientist, Dr. Ellen Stofan, made global headlines 

with her prediction that ‘‘we are going to have strong indications of life beyond 

Earth in the next decade and definitive evidence within the next 20 to 30 years.’’ 

I am glad Dr. Stofan has joined us today. 

Within our solar system, the question of whether life exists or existed on Mars 

continues to capture the public imagination.In the past year, NASA’s Curiosity 

Rover made several major scientific discoveries relevant to the search for life on 

Mars. 

Curiosity measured a spike in levels of the organic chemical methane in the local 

atmosphere of its research site. It also detected other organic molecules in drill samples from a mudstone that once sat at the bottom of a lake. 

And Jupiter’s moon, Europa, shows strong evidence of an ocean of liquid water 

beneath its surface, which could host conditions favorable to some form of life. 

These instruments will help scientists investigate the chemical makeup of 

Europa’s potentially habitable environment. 

Last July, astronomers, with the help of the Kepler Space Telescope, confirmed 

the discovery of Kepler 452-b, the first near-Earth-size planet in the ‘‘habitable 

zone’’ around a sun-like star. This discovery marks another milestone in the journey 

to find another ‘‘Earth.’’ 

The Transiting Exoplanet Survey Satellite, which will launch in 2017, and the 

James Webb Space Telescope, which will begin in 2018, will help scientists discover 

more planets with potential biosignatures in their atmospheres—such as evidence 

of oxygen and methane gas. 

Around the world a relatively small number of astronomers monitor radio and optical emissions throughout the universe. They try to filter out the cosmic noise and 

interference of satellites and spacecraft to find anomalies that could represent life. 

The search for life beyond Earth also inspires a new generation of explorers. It 

motivates students to study math, science, engineering, and computer science. 

Just a few months ago, astronomers confirmed that Tom Wagg, a 15 year old student, discovered exoplanet WASP-142b, which orbits a star approximately 1,000 

light years away in the constellation Hydra. 

It is in our human nature to seek out the unknown and to discover the universe 

around us. The stars compel us to look upward and lead us from this world to another. Many Americans often gaze into the beauty of the night sky in awe, some 

may wonder if there is life beyond our pale blue dot. 

I thank our witnesses and look forward to hearing their testimony and particularly about recent developments in the field of astrobiology and the search for life. 

Chairman SMITH. And now I will recognize the gentlewoman 

from Texas, Eddie Bernice Johnson, the Ranking Member, for her 

opening statement. 

Ms. JOHNSON OF TEXAS. Thank you very much, Mr. Chairman, 

and good morning. Let me welcome our distinguished panel of witnesses today. I do look forward to your testimony. 
12 

I want to welcome Mr. LaHood to the Committee and simply say 

that the first week of this month I visited the Curiosity team in 

France, and the excitement is beyond measure. 

Administrator Bolden stated in the preface of NASA’s Strategic 

Plan that ‘‘when we explore the solar system and the universe, we 

gain knowledge about the dynamics of the Sun and the planetary 

system and whether we are alone.’’ 

With respect to the question of whether we are alone, the search 

for life beyond Earth is a topic this Committee has devoted a lot 

of attention to over the past two years. I don’t know if we plan on 

taking up life somewhere else. I don’t know where our Chairman 

wants to go, but I’m interested in following him. 

I understand that the purpose of today’s hearing is to get another update on that topic. It is my hope that our witnesses will 

also take some time to discuss how their research activities can be 

used to help foster excitement in our young people and spur them 

to pursue careers in science, technology, engineering, and math. 

That’s important because these young people are the future science 

and technological leaders and innovators who will be critical to our 

nation’s growth and progress going forward. While it’s exciting to 

search for intelligent life elsewhere in the universe, I hope we don’t 

neglect nurturing the intelligent life we have right here in our 

country. 

As a final note, I want to recognize that this is a return visit by 

Dr. Lunine. One year ago he and Governor Mitch Daniels testified 

before the Committee on their National Research Council panel’s 

report entitled ‘‘Pathways to Exploration: A Review of the Future 

of Human Space Exploration.’’ And that was completed pursuant to 

the NASA Authorization Act of 2010. I highly recommend that our 

newer colleagues on the Committee and in the rest of the Congress 

as a whole for that matter read this report, as I found it to be objective in its endorsement of the goal of sending humans to Mars 

and thoughtful in its recommendations for an exploration program 

to send humans to the surface of Mars, a central goal established 

by this Committee in the House-passed NASA Authorization Act of 

2015. 

And with that, I again want to thank our witnesses and I yield 

back. Thank you. 

[The prepared statement of Ms. Johnson of Texas follows:] 

PREPARED STATEMENT OF COMMITTEE RANKING MEMBER

EDDIE BERNICE JOHNSON

Good morning and welcome to our distinguished panel of witnesses. I look forward 

to your testimony. 

Administrator Bolden stated, in the preface of NASA’s Strategic Plan, that when 

we explore the solar system and the universe, we gain knowledge about the dynamics of the Sun and the planetary system and whether we are alone. 

With respect to the question of whether we are alone, the Search for Life Beyond 

Earth is a topic this Committee has devoted a lot of attention to over the past two 

years. I understand that the purpose of today’s hearing is to get another update on 

that topic. It is my hope that our witnesses will also take some time to discuss how 

their research activities can be used to help foster excitement in our young people 

and spur them to pursue careers in Science, Technology, Engineering, and Mathematics. 

That’s important, because those young people are the future science and technological leaders and innovators who will be critical to our Nation’s growth and 

progress going forward. While it’s exciting to search for intelligent life elsewhere in 
13 

the universe, I hope we don’t neglect nurturing the intelligent life we have right 

here in this country now. 

As a final note, I want to recognize that this is a return visit by Dr. Lunine. One 

year ago, he and Governor Mitch Daniels testified before this Committee on their 

National Research Council panel’s report titled ′′Pathways to Exploration: A Review 

of the Future of Human Exploration′′ that was completed pursuant to the NASA Authorization Act of 2010. 

I highly recommend that my newer colleagues on the Committee, and in the rest 

of the Congress as a whole for that matter, read this report as I found it to be objective in its endorsement of the goal of sending humans to Mars, and thoughtful in 

its recommendations for an exploration program to send humans to the surface of 

Mars—a central goal established by this Committee in the House-passed NASA Authorization Act of 2015. 

With that, I again want to welcome our witnesses to today’s hearing, and I yield 

back. 

Chairman SMITH. I thank the Ranking Member for those nice 

comments. 

Let me introduce our witnesses. Our first witness is Dr. Ellen 

Stofan, NASA’s Chief Scientist. She serves as principal advisor to 

NASA Administrator Charles Bolden on the agency’s science programs and science-related strategic planning and investments. This 

is Dr. Stofan’s second term at NASA, as she recently held a number of senior scientist positions at the Jet Propulsion Laboratory. 

Dr. Stofan is the recipient of the Presidential Early Career Award 

for Scientists and Engineers. She earned her bachelor’s degree from 

William and Mary and her master’s and doctorate degrees in geological sciences from Brown University. 

Our second witness today is Dr. Jonathan Lunine, the Director 

of the Cornell Center for Astrophysics and Planetary Science at 

Cornell University, where he specializes in astrobiology. Dr. Lunine 

has extensive experience in the search for life on other planets. He 

worked as an interdisciplinary scientist on the Cassini mission, 

which showed that one of Saturn’s moons may host micro-bio life, 

and on the James Webb Space Telescope, which will study the origins of life in the near future. Dr. Lunine received his bachelor’s 

degree in physics and astronomy from the University of Rochester 

and his master’s and Ph.D. in planetary science from the California 

Institute of Technology. 

Our third witness is Dr. Jacob Bean, Assistant Professor of Astronomy and Astrophysics at the University Of Chicago. Dr. Bean 

also is the leader of the Bean Exoplanet Group, which uses telescopes to detect and characterize exoplanets. Dr. Bean’s work has 

used the Hubble and Spitzer telescopes to make breakthroughs in 

astrobiology, which include the measurement of the first spectrum 

of a super-Earth planet. Dr. Bean also develops new instruments 

for exoplanet detection and characterization and is helping to design the giant Magellan telescope, which will soon be the world’s 

largest telescope. Dr. Bean received his undergraduate degree in 

physics from the Georgia Institute of Technology and his Ph.D. in 

astronomy from the University of Texas in Austin. 

Our final witness today is Dr. Andrew Siemion. Dr. Siemion is 

an astrophysicist at the University of California Berkeley and 

served as Director of the U.C. Berkeley Center for Search for Extraterrestrial Intelligence Research. Dr. Siemion’s research interests include studies of time variable celestial phenomena, astronomical instrumentation and SETI, and Dr. Siemion also is a leader of the Breakthrough Listen Initiative, a ten-year, $100 million 
14 

initiative to search for extraterrestrial life that is possibly the most 

comprehensive search for alien communications to date. Dr. 

Siemion received his Ph.D. in astrophysics from the University of 

California at Berkeley. 

We welcome you all. You’re clearly experts in the field. And, Dr. 

Stofan, you begin. 

TESTIMONY OF DR. ELLEN STOFAN, 

CHIEF SCIENTIST, NASA 

Dr. STOFAN. Thank you. I’m pleased to appear before the Committee to discuss astrobiology and the search for life beyond Earth. 

If I could have the first slide, please. 

[Slide.] 

NASA’s science missions are providing strong evidence of possible habitable environments beyond Earth. With future technology 

and instruments currently under development, we will explore the 

solar system and beyond, and could indeed, perhaps in as little as 

10 to 20 years, discover some form of life, past or present. 

Our search is making amazing progress. When I was a Ph.D. student, scientists certainly suspected that planets might be commonplace in the universe, but we have not found evidence of a single 

one. Twenty years ago, we found evidence of such a planet, and 

today, thanks to NASA’s space missions and ground-based telescopes, we have identified nearly 5,000 planets orbiting other stars, 

and we now believe that that the vast majority of stars in the universe have planets around them. In July, the Kepler mission confirmed the first near-Earth-size planet in the ‘‘habitable zone’’ 

around a sun-like star, Kepler-452b. 

On Mars, a series of NASA missions culminating in the Curiosity 

Rover, which touched down in Gale Crater nearly three years ago, 

have allowed us to make fundamental discoveries. Next slide. 

[Slide.] 

We now know that Mars was once a water world much like 

Earth, with clouds and a water cycle, and indeed some running 

water currently on the surface. For hundreds of millions of years, 

about half of the northern hemisphere of Mars had an ocean, possibly a mile deep in places. 

Indeed, we now know that we live in a soggy solar system, and 

undoubtedly, in a soggy universe. For instance, Jupiter lies outside 

the habitable zone and we would expect water there to be frozen. 

Yet we now have evidence of liquid oceans on three moons of Jupiter under the icy crusts of those worlds. And using the Hubble and 

Spitzer Space Telescopes, we have found signs of water in the 

atmospheres of planets around other stars. 

So what lies ahead in the next decade of exploration? I’d like to 

describe just some of the highlights. Life as we know it requires 

water, liquid water, that’s been stable on the surface of a planet 

for a very long time. That’s why Mars is our primary destination 

in the search for life in our solar system. The Mars 2020 Rover 

mission will study Martian rocks and soils to understand past habitable conditions on Mars and to seek signs of ancient microbial 

life. If we do find evidence of life on Mars, it will likely be fossilized 

microorganisms preserved in the rock layers. The Mars 2020 Rover 

will begin the search, but as a field geologist, I can tell you it’s 
15 

going to be hard to find. That’s why I believe it will take human 

explorers who can move quickly and make intuitive decisions on 

their feet to really identify it, and in doing so, inspire that next 

generation of explorers. 

Over the next decade, our journey to Mars involves the development of a commercial crew capability for low-Earth orbit, the Space 

Launch System and Orion, to go beyond low-Earth orbit and an asteroid redirect mission. 

Beyond Mars, the President’s fiscal year 2016 budget request 

supports the formulation and development of a new mission to the 

Jovian moon Europa. If I could have the next slide. 

[Slide.] 

We estimate that Europa has twice as much water as the Earth’s 

oceans, and Hubble has observed plumes of water at one of 

Europa’s poles. A Europa mission could potentially, among other 

things, analyze these water plumes to determine the composition 

of those oceans. 

Beyond our solar system, there are countless other worlds that 

could harbor life. In 2017, NASA will launch the Transiting 

Exoplanet Survey Satellite to look for rocky planets near the habitable zone of the closest stars. Next slide. 

[Slide.] 

We will then use the James Webb Space Telescope to analyze the 

atmospheres of some of these planets. The President’s fiscal year 

2016 budget request also supports the pre-formulation of a Wide 

Field Infrared Survey Telescope with the capability of directly imaging planets around the nearest stars and analyzing their 

atmospheres. 

Since Earth remains, for now, the only instance of an inhabited 

planet, the search for life also requires that we further develop our 

understanding of life on Earth. Through our research here, we 

have learned that life is tough, tenacious, metabolically diverse, 

and highly adaptable to local environmental conditions. 

Astrobiologists have discovered life in numerous extreme environments and in extraordinary forms from bacteria that consume 

chemicals that would be toxic to most other life, to microbes that 

live under high levels of radiation. 

Perhaps even more interesting is the possibility that life could 

exist in the absence of liquid water. That’s why scientists are interested in exploring some of the more unusual places in our solar 

system and beyond, such as Saturn’s moon Titan, where it rains 

liquid methane and ethane. Could such an environment harbor 

life? We don’t know yet. 

Ultimately, of course, the search for life is a crosscutting theme 

in all of NASA’s space science endeavors, bringing together research in astrophysics, Earth science, heliophysics, and planetary 

science. Astrobiology is guided by a community-constructed roadmap generated about every five years with the next roadmap slated 

for release later this year. 

In addition, in April NASA announced the formation of an initiative dedicated to the search for life on planets outside our solar system. The Nexus for Exoplanet System Science is an interdisciplinary effort that connects top research teams and provides a syn-
16 

thesized approach in the search for planets with the greatest potential for harboring life. 

From research, to our knowledge of where to go and what to look 

for, to the capabilities of finding it both within our solar system 

and beyond, we are making great discoveries. 

Thank you for the opportunity to testify today. 

[The prepared statement of Dr. Stofan follows:] 
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Chairman SMITH. Thank you, Dr. Stofan. 

Dr. Lunine. 

TESTIMONY OF DR. JONATHAN LUNINE, 

DAVID D. DUNCAN PROFESSOR 

IN THE PHYSICAL SCIENCES, AND DIRECTOR, 

CENTER FOR RADIOPHYSICS AND SPACE RESEARCH, 

CORNELL UNIVERSITY 

Dr. LUNINE. Thank you, Chairman Smith, Ranking Member 

Johnson, and members of the committee. Thank you for the opportunity to present my views on the search for life beyond Earth. 

These views are my own and they come from 30 years of working 

in the field of planetary science at various institutions in the 

United States and abroad. 

One of the most important outcomes of the last two decades of 

solar system exploration is the identification of four bodies in our 

solar system that appear capable of harboring life. These bodies 

possess a particular set of characteristics that make them the best 

leads in the search for life beyond the Earth. And if I could have 

the first slide, the first of these bodies is Mars. 

[Slide.] 

In its first billion years, Mars had abundant liquid water, stabilized and protected by a much denser atmosphere than the tenuous shell we see today. During this time, life might have begun, 

survived for a while on the surface, and then was extinguished or 

retreated underground as the atmosphere was lost. If I could have 

the second slide—— 

[Slide.] 

The second of these objects is Jupiter’s moon Europa. It’s a body 

the size of our own moon. It has a very large saltwater ocean, twice 

the water that we have in our own ocean. This ocean is in contact 

with a rocky core and abundant sources of energy. As yet, we don’t 

know whether organic molecules exist inside of this ocean, but we 

strongly suspect that they are there. Equally important, we don’t 

know how far beneath Europa’s surface the ocean lies. Knowing 

that will allow a strategy to be formulated for searching for life 

there. 

[Slide. 

Next slide is Titan, a Saturnian moon that’s larger than the 

planet Mercury and the only moon in our solar system to host a 

dense atmosphere of nitrogen and methane. Cassini and its lander 

Huygens have revealed methane clouds, rain, gullies, river valleys, 

and methane/ethane seas, and so we cannot resist asking whether 

some biochemically novel form of life might have arisen in this exotic frigid environment. Titan is a test for the universality of life 

as an outcome of cosmic evolution. To quote the historian Stephen 

Pyne, ‘‘What the Galapagos Islands did for the theory of evolution 

by natural selection, Titan might do for exobiology.’’ 

[Slide.] 

Finally, next slide, Enceladus has surprised us. This small Saturnian moon has a large plume of material emanating from a series 

of fractures in its south polar region. Make a list of requirements 

for terrestrial-type life—liquid water, organics, minerals, energy, 
23 

chemical gradients—and Cassini has found evidence for all of them 

in the plum of Enceladus. 

So how do we actually find the signs of life in these bodies? The 

evidence will not be entire living organisms. Much more likely is 

that we will detect signatures that indicate that life is at work or 

was at work in these environments. In contrast to nonbiological 

processes, biology is built from a very limited, selected set of molecules, and so if we can recognize patterns in the makeup of organic molecules and their isotopes, we then have strong evidence 

of biology at work. 

At Mars, finding sources of methane and measuring their isotopes is one way to get at this question. Another is to seek wellpreserved organic materials in the soil to see if they record the signatures of biology. And the Mars 2020 Rover will do the heavy lifting here. 

For Europa, the Europa mission now in development will provide 

the essential information needed to decide, among other things, 

whether organics and water are welling up through the cracks on 

the surface and whether plumes exist and can be measured. Doing 

this mission, doing it now is absolutely crucial to any general strategy for the search for life. 

For Titan, the search to target one of the great methane/ethane 

seas by dropping a capsule capable of floating across the surface. 

We don’t know what kind of biochemistry we’re looking for here 

and so a generalized search for patterns and molecular structures 

and abundances that indicate deviation from abiotic chemistry is 

appropriate. 

And finally, Enceladus provides us with the most straightforward 

way to look for life. Merely flying through the plume of Enceladus, 

as Cassini has done multiple times, with modern instrumentation 

intended to detect the signatures of life, is sufficient to do the 

search. 

The long flight times in the outer solar system in particular dictate the planning for missions to Enceladus, Europa, and Titan 

must begin now and must be pursued with vigor if they’re to happen in the next two decades. It is remarkable that we have found 

four destinations in our own solar system where life may actually 

exist or have existed for quite some time in the past and now is 

the time to actually go search for the life. 

Thank you. 

[The prepared statement of Dr. Lunine follows:] 
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Chairman SMITH. Thank you, Dr. Lunine. 

And Dr. Bean. 

TESTIMONY OF DR. JACOB BEAN, 

ASSISTANT PROFESSOR, 

DEPARTMENTS OF ASTRONOMY 

AND ASTROPHYSICS, GEOPHYSICS, 

UNIVERSITY OF CHICAGO 

Dr. BEAN. Mr. Chairman and Members of the Committee, good 

morning, and thank you for the opportunity to serve as a witness 

for this important hearing. 

My testimony today will be focused on the topic of exoplanet 

spectroscopy in the context of the search for life beyond Earth. The 

main point I want to convey is that an expanded exoplanet exploration program with a flagship exoplanet spectroscopy space telescope as its centerpiece could answer one of humanity’s most fundamental questions: Is there life elsewhere in the universe? 

Extrasolar planets, or exoplanets for short, are planets outside 

our solar system that orbit stars other than our Sun. This year 

marks just the 20th anniversary of the first detection of an 

exoplanet orbiting a sun-like star, but progress in the field has 

been rapid in the intervening years. In particular, the launch of 

NASA’s Kepler telescope in 2009 has revolutionized the field. The 

Kepler mission has advanced to the point that it is now focused on 

finding Earth-size planets orbiting their host stars in the so-called 

‘‘habitable zone,’’ which is the distance at which the temperature 

on the surface of a terrestrial planet could be right for liquid water 

to be present. 

A handful of Earth-size habitable-zone exoplanets have been 

found over the last few years. These discoveries have grabbed the 

attention of the scientific community and the public because they 

suggest that Earth-like planets may exist around relatively nearby 

stars, and that we therefore have it within our grasp to search for 

life on other worlds in our lifetimes. 

The next step towards determining if there are any truly habitable planets or even inhabited planets is to study the atmospheres 

of candidate worlds using the technique of astronomical spectroscopy. Planetary atmospheres are a key factor controlling the habitability of a planet because they are reservoirs of biogenic elements 

and regulators of planetary surface conditions. Furthermore, planetary atmospheres can be influenced by interactions with a biosphere, and thus may be a marker of life itself absent direct observation or communication. 

Astronomers have made progress revealing the nature of the 

atmospheres of hot, gas giant-type exoplanets using the Hubble 

and Spitzer Space Telescopes and the ground-based Keck and Gemini telescopes. These investigations have yielded constraints on the 

abundances of key chemical species, the identification of clouds, 

and the determinations of temperature maps. 

Astronomers eagerly await the launch of the James Webb Space 

Telescope in 2018. Among its many new important capabilities, the 

Webb telescope will dramatically extend the reach of exoplanet 

spectroscopy. It may even have the capability to determine the 
31 

presence of major molecules like water and carbon dioxide and 

measure the temperatures of Earth-size exoplanets atmospheres. 

However, Webb will be hard-pressed to detect evidence for life, only 

made possible with fortuitous planets, extraordinary performance 

of the instrument, and large amounts of biosignature gases in the 

planets themselves. 

A flagship space telescope with next-generation optics will likely 

be needed to detect evidence for life on other Earth-like exoplanets. 

The astrophysics community is currently ramping up for a Decadal 

Survey that will prioritize large space missions to follow the Webb 

telescope. 

At the wise urging of NASA leadership, the community is currently developing concepts for telescopes that could take spectra of 

Earth-like exoplanets in preparation for the decadal selection process. The top-priority space telescope from the previous Decadal 

Survey, currently dubbed WFIRST–AFTA will have capabilities 

that lay a foundation for a future life-finder telescope. One of the 

science goals of the WFIRST–AFTA mission is to obtain improved 

statistics on the frequency of potentially habitable planets. In addition, NASA is currently considering including an exoplanet spectrometer on the telescope. This instrument would not have the capability to make measurements for Earth-like planets but it would 

advance the science and technology in that direction. 

As a final point, it is important to keep in mind that a future 

life-finder mission cannot be a success in the absence of other 

projects. The need for comprehensive knowledge to confront the 

question of life on other planets is why I think that ultimately an 

expanded program in exoplanet exploration would be the best way 

forward. Although a flagship space telescope would be the crown 

jewel, this program should be driven by the question of life rather 

than the construction of a single facility. It would take courage and 

perseverance by scientists, government leaders, and the public all 

working together to act on this vision and see it through, but our 

ability to rise to this kind of challenge is what makes America exceptional. 

From the Apollo program through the Voyager, Hubble, and 

Mars Rover programs, with the recent stunning success of the New 

Horizons mission to Pluto, and today with the launch of the Webb 

telescope just a few years away, our country leads the way in 

projects that are lasting milestones of space exploration. The 

search for life beyond our planet represents the next great space 

exploration challenge that would continue this legacy. 

Mr. Chairman and members of the committee, thank you again 

for the opportunity to be here as a witness, and I’d be happy to 

take questions. 

[The prepared statement of Dr. Bean follows:] 
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Chairman SMITH. Thank you, Dr. Bean. 

And Dr. Siemion. 

TESTIMONY OF DR. ANDREW SIEMION, 

DIRECTOR, SETI RESEARCH CENTER, 

UNIVERSITY OF CALIFORNIA, BERKELEY 

Dr. SIEMION. Chairman Smith, Ranking Member Johnson, and 

Members of the Committee, thank you for the opportunity to testify 

today. 

Searches for Extraterrestrial Intelligence, SETI experiments, 

seek to determine the distribution of advanced life in the universe 

through detecting the presence of technology, usually by searching 

for electromagnetic radiation from communication technology, but 

also by searching for evidence of large-scale energy usage or interstellar propulsion. Technology is thus used as a proxy for intelligence. If an advanced technology exists, so, too, does the advanced 

life that created it. 

We know of no way to directly detect intelligent life, but if other 

intelligent life exists and possesses a technological capability similar to our own, we could detect their technology using the techniques of modern astronomy. Large radio telescopes such as the 

Green Bank Telescope in West Virginia and the Arecibo Observatory in Puerto Rico are superb facilities for a wide range of astronomy, including pulsar studies that test Einstein’s theory of general 

relativity, mapping the gas in nearby galaxies, and probing the earliest epochs of the universe. In addition, these facilities are among 

the world’s best in searching for the faint whispers of distant technologies. 

A variety of radio study experiments are underway at both the 

Green Bank Telescope and the Arecibo Observatory, including 

some that allow us to observe in parallel with other astronomers 

without interfering with their work, a technique we call ‘‘piggyback 

observing.’’ Several other U.S. and international radio telescopes 

are also currently being used for radio study, including the private 

Allen Telescope Array in northern California, the Low-Frequency 

Array in Europe, and the Murchison Widefield Array in Australia. 

Many radio study searches are taking advantage of the wealth 

of new information on our galaxy’s exoplanet population now being 

revealed by missions such as NASA’s Kepler spacecraft. 

In a very exciting new project, a group based at the University 

of California San Diego are using the Lick Observatory near San 

Jose to conduct a search for pulsed lasers in the near-infrared, 

wavelengths just a hair longer than optical light but much better 

at penetrating the dusty space between the stars. 

These SETI experiments are funded by a combination of government and private sources, including notable contributions from the 

John Templeton Foundation. Ensuring that facilities like the Green 

Bank Telescope, Arecibo, and the Lick and Keck Observatories continue to exist as world-class astronomical facilities is critical to 

their continued use in SETI experiments. 

One of the most exciting prospects for SETI in the next decade 

is the Breakthrough Listen initiative, a $100 million, ten-year effort funded by the Breakthrough Prize Foundation that will con-
38 

duct the most sensitive, comprehensive, and intensive search for 

advanced intelligent life on other worlds ever performed. 

I have an animation I would like to show you illustrating some 

components of Breakthrough Listen. 

[Slide.] 

Here, we see the Milky Way Galaxy, a galaxy that we now know 

hosts tens of billions of planets in the habitable zone of their star, 

planets that might have liquid water on their surface. If intelligent 

life arose on some of these planets and developed radio technology, 

the emissions from their technology would proceed at the speed of 

light out into the Milky Way. But for how long? Life may arise, it 

may develop intelligence, and finally, a communicative technology. 

But that final stage may only last for a few thousand years. But 

the evidence of their technology, the bubble of their electromagnetic 

radiation, will continue to propagate throughout the galaxy and 

could eventually be detectable at the Earth. 

With Breakthrough Listen, we will conduct deep observations for 

these types of emissions from 1 million of the nearest stars to the 

Earth that will be at least 10 times more sensitive than ever performed. These observations will cover at least five times more of 

the radio spectrum than any previous experiment. We will conduct 

these observations using the Green Bank Telescope in West Virginia, as well as the Parkes Radio Telescope in Australia. 

It is undoubtable that the next decade will be an incredibly exciting time for astrobiology. Data provided by missions like the 

Transiting Exoplanet Survey Satellite and the James Webb Space 

Telescope virtually guarantee dramatic new insight into exoplanet 

science, including identifying and characterizing some of the nearest exoplanets to the Earth. At the same time, we will continue to 

learn more about the development of life on Earth and the potential for life elsewhere in our own solar system. If history is any 

guide, these discoveries will only heighten our imagination about 

the possibilities for advanced life elsewhere in the universe. 

Thank you. 

[The prepared statement of Dr. Siemion follows:] 
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Chairman SMITH. Thank you, Dr. Siemion. 

As you might guess, we all have thousands of questions and 

we’re somewhat limited in our time by five minutes, but, Dr. 

Stofan, I’d like to address a couple of questions to you. 

One, I am absolutely astounded by the announcement by NASA 

that briny water may be on the surface of Mars. Is that the case? 

When the Mars Curiosity Rover reported no evidence of water, I 

thought that was the end of it, but if we have this water on the 

surface of Mars, why is it we do not have any photographs of that 

water? 

Dr. STOFAN. Indeed, the new results that we just got show that 

the recurring slope lineae, these features that are on the sides of 

some craters on slopes, seasonally over time it seems that water 

melts—— 

Chairman SMITH. Right. 

Dr. STOFAN. —briny water carries those materials down slope, 

and we’ve finally been able to put all the evidence together, including chemical observations, to say, okay, that’s really what’s forming 

these things, which we’re incredibly excited about. 

The problem is these features are very transient. There’s not a 

whole lot of water that’s carrying those salts and so it’s very hard 

to see with the resolution of spacecraft that we see. But again, we 

can certainly trace of the chemical signatures. 

We also, at the Phoenix landing site, were able to see the evidence of liquid water, including a little droplet on the spacecraft. 

So, you know, water is there on Mars. It’s not in huge abundance 

right near the surface but we know it’s at the poles, we know it’s 

under—— 

Chairman SMITH. When will we have evidence of liquid water? 

Anytime soon? 

Dr. STOFAN. I’m afraid I can’t answer exactly when will have— 

we feel that the evidence we showed yesterday is certainly good 

evidence of liquid water, but you have to understand that those 

water—when it’s flowing on the surface, it’s very, very hard to detect. 

Chairman SMITH. Okay. Thank you. 

Next question is where are we in your opinion most likely to detect any kind, any form of life, even if it’s bacteria or microbes or 

whatever? Is it going to be Mars? Is it going to be Europa? Is it 

going to be an exoplanet? Is it going to be some technological communication? Where do you think the best prospects lie? 

Dr. STOFAN. Well, I certainly believe that it’s going to be Mars, 

and I think, as you heard from me and you heard from Dr. Lunine, 

we’re very optimistic about the 2020 Rover and its potential for 

looking for signs for ancient microbial life. Now, again, that’s—— 

Chairman SMITH. Okay. 

Dr. STOFAN. —not the most exciting in a lot of people’s terms to 

find fossilized microbes, but that’s—or the signatures—— 

Chairman SMITH. Yes. 

Dr. STOFAN. —that those microbes existed, but I’m really optimistic, but again, I think it’s going to take humans on the surface 

of Mars to really get at the definitive evidence to study that liquid 

water—— 

Chairman SMITH. That we’re talking about. 
51 

Dr. STOFAN. —that we want to see. 

Chairman SMITH. Okay. Thank you, Dr. Stofan. 

Dr. Lunine, how would you rank the various—you—let me start 

again. You mentioned four locations: Mars, Europa, Titan, and Saturn—one of Saturn’s moons Enceladus. Was that in order of likelihood or do you have a preference or a prediction as to where we 

might most likely find evidence of some form of life? 

Dr. LUNINE. Well, that was actually in order moving outward 

from the Sun—— 

Chairman SMITH. Oh, okay. 

Dr. LUNINE. —so there was no implied—or, you know, the question is whether in any environment that can support life does life 

actually begin, does it form? And I don’t know the answer to that 

and no one else does—— 

Chairman SMITH. Okay. 

Dr. LUNINE. —and that’s why in my view we need to look at all 

of these bodies where there is very strong evidence, compelling evidence of what’s called a habitable environment, an environment 

where life could actually be sustained. So—— 

Chairman SMITH. And when we find out what the thickness of 

the ice is on Europa, that’s the time to send a probe there I gather? 

Dr. LUNINE. Yes. There’s a lot of ground work that has to be 

done on Europa. We don’t know if there are organic molecules. 

Chairman SMITH. Okay. 

Dr. LUNINE. The Europa mission will tell us whether there are 

fresh organics in the cracks. 

Chairman SMITH. Okay. 

Dr. LUNINE. If there are, that would be the place to go. 

Chairman SMITH. Thank you. Dr. Bean, when do you think we 

will have the capability of detecting biosignatures in the 

atmospheres of exoplanets? 

Dr. BEAN. Yeah, so as I mentioned, I think the James Webb 

Space Telescope, which is planned to launch in 2018, will be our 

first chance—— 

Chairman SMITH. Right. 

Dr. BEAN. —to do that. If we get lucky and we find the kind of 

planets orbiting very nearby stars, then we may be able to search 

for biosignature gases—— 

Chairman SMITH. With James Webb? 

Dr. BEAN. Yes. 

Chairman SMITH. And not before? You think it’s going to 

take—— 

Dr. BEAN. Definitely not before. 

Chairman SMITH. Okay. I’m going to ask you also what do you 

think the odds are of actually finding a biosignature, say, in the 

next ten years. Well, let me ask you, likely or unlikely? 

Dr. BEAN. I’d say that’s unlikely, but we are optimistic that we 

can take—— 

Chairman SMITH. You can say—— 

Dr. BEAN. —important steps towards doing that over the next 10 

years. 

Chairman SMITH. Okay. Thank you. Dr. Bean, I was hoping 

you’d be a little bit more optimistic than that, but anyone want to 

give a one out of three, one out of four? What would you say? 
52 

Dr. BEAN. One out of five. 

Chairman SMITH. One out of five, that’s better than otherwise. 

Okay. Thank you, Dr. Bean. 

And, Dr. Siemion, last question for you. Could you briefly tell us 

the advantages and disadvantages of radio and optical astronomy? 

I know we’re trying both. You seemed to focus a little bit more on 

radio in your comments, but there’s advantages and disadvantages 

to both, and do you have a preference or not, and if so, what are 

the advantages and disadvantages? 

Dr. SIEMION. Yeah, I think you’re absolutely right that historically SETI has concentrated on the radio portion of the electromagnetic spectrum. 

Chairman SMITH. Yeah. 

Dr. SIEMION. But as we’ve developed technology on Earth that allows us to communicate at optical wavelengths, we’ve—— 

Chairman SMITH. Yes. 

Dr. SIEMION. —moved some of our efforts in SETI to those wavelengths as well. The truth is is that we don’t know what part of 

the electromagnetic spectrum we might eventually receive, some 

signal or some evidence of a technological civilization elsewhere. So 

it behooves us to search as much of that spectrum as we can, and 

that’s why we focus on both the radio and the optical. 

Chairman SMITH. Okay. Thank you, Dr. Siemion. 

My time is expired but, Dr. Bean, just a quick comment. You 

know that 20 percent is actually pretty high considering how historic that would be, and I think we all would agree it might be the 

most interesting news in, say, the last 100 years, so that 20 percent is something I think is not insignificant. So I appreciate your 

comments. 

The Ranking Member, the gentlewoman from Texas, is recognized for her questions. And let me say, going back to her opening 

statement, that it’s not often that the Chairman hears the Ranking 

Member say she’s going to follow the Chairman, so I just wanted 

to—— 

Ms. JOHNSON OF TEXAS. If you go to Mars. 

Chairman SMITH. All yours. 

Ms. JOHNSON OF TEXAS. Thank you very much, Mr. Chairman. 

Dr. Lunine, today, we are speaking primarily about astrobiology 

that can be carried out robotically. However, humans will one day 

return to deep space and carry out scientific exploration on bodies 

such as Mars. To that end, it has been over a year since the National Academies released the Pathways to Exploration study, 

which you co-authored. That report found that the horizon goal for 

human space exploration is Mars, and as you may know, this Committee agrees with that. Has NASA been in discussions with you 

on the results of that report? And if so, what is the status of the 

response of that report and how can this Committee be helpful? 

Dr. LUNINE. Well, the NASA Advisory Committee did actually 

have a session at one of their meetings on the subject of our report, 

and one of our committee members, Mary Lynne Dittmar, was 

there and had a dialogue with the committee and also folks from 

NASA, including Bill Gerstenmaier. So I think there’s some dialogue and thinking going on. I look forward to having more dialogue with NASA on the report. I think it’s still very fresh and has 
53 

a lot to contribute to the question of how and when humans will 

move beyond low-Earth orbit, and so I look forward to that dialogue. 

Ms. JOHNSON OF TEXAS. Good. In your view, what if any of the 

issues does this Committee and the Congress need to address? 

Dr. LUNINE. In the context of that report? 

Ms. JOHNSON OF TEXAS. Yes. 

Dr. LUNINE. Well, you know, to quote from that report, we were 

concerned about the question of flight rates in the near term and 

the question of how the destinations or pathways might be chosen, 

and I still think those are the key operative elements in the recommendations from our report. 

Ms. JOHNSON OF TEXAS. Thirty years from now, elementary 

school children will be leading the scientific exploration of the solar 

system and beyond. Our knowledge of other bodies near and far 

will have changed. Humans may have visited Mars and even the 

two of us here in this Committee won’t be around. But life beyond 

Earth may have been detected by then. So I would like to ask all 

the panel members, as we think about where we are today and 

where we might be 30 years from now, is there anything that Congress should be considering to ensure that today’s schoolchildren 

are well-equipped to lead a new era that can include knowledge of 

life beyond Earth? 

Dr. STOFAN. I’m a strong believer that NASA plays an incredibly 

important role in inspiring the next generation. And Charlie Bolden loves to say that everything we do at NASA is about STEM education. Every time we launch a rocket, every time we do something 

like encountering Pluto, we are inspiring the next generation to 

want to explore, to question why. And I would like to see NASA 

stay on the steady course we have been with obviously this Committee’s support to continue that exploration and move forward 

with moving humans out beyond the low-Earth orbit. 

Dr. LUNINE. This nation has done some incredible things in exploring the solar system. One example that excites school kids is 

the Cassini spacecraft can actually probe the large methane seas 

of Titan and determine their depths and their composition by sending radio signals through those seas as it flies by Titan. And so 

we’re actually doing ocean exploration a billion miles away from 

the Earth, and that’s only one example. School kids are fascinated 

by that. They want to be a part of it. And in order for them to be 

a part of it, we have to have continuity in exploration. We have to 

continue these wonderful missions so that there isn’t effectively a 

generation-long gap in these discoveries. 

Dr. BEAN. To get back at Chairman Smith’s earlier question 

about putting a number on the chance of finding life, I want to emphasize that scientific process is a step-by-step, deliberate process, 

and so being able to maintain, like Jonathan said, a continuity in 

funding these programs and continuing this deliberate approach I 

think is extremely important. 

Dr. SIEMION. I think the only thing that I have to add to what 

my other panel members have said is is that the search for life I 

think has a particularly compelling aspect to it for young people, 

and I think to the extent that that can be highlighted and taken 
54 

advantage of to encourage more young people to enter careers into 

space and science and technology is wonderful. 

Ms. JOHNSON OF TEXAS. Thank you very much. My time is expired. 

Chairman SMITH. Thank you, Ms. Johnson. 

The gentleman from Texas, Mr. Babin, the Chairman of the 

Space Subcommittee, is recognized for his questions. 

Mr. BABIN. Yes, sir. Thank you, Mr. Chairman. And welcome all 

of you panelists. We appreciate and it’s very, very fascinating to 

hear your testimony. 

In my district, Texas 36, the Johnson Space Center 

Astromaterials Curation facility provides the services for all return 

planetary materials that do not require planetary protection laboratories. This facility has been in operation since the Apollo lunar 

samples were returned. In the next decades we anticipate missions 

to collect samples from the Moon, from Mars, from comets, and 

from asteroids. Each of these new sample collections will require 

new curation laboratories while the facilities for the older collections will require routine maintenance and upgrades. 

Samples to be returned from Mars pose even greater challenges 

due to special planetary protection requirements. Dr. Stofan, what 

steps is NASA taking to upgrade its curation facilities and protect 

against the transfer of viable organisms from Earth to celestial 

bodies, which may harbor life? 

Dr. STOFAN. We have two different committees at NASA, certainly, the Planetary Protection Group where we take these issues 

extremely seriously both for forward contamination of Mars and 

the backward contamination for when we eventually return samples to the Earth. So that’s one aspect of where we are certainly 

doing research. We’re doing testing of all our Mars spacecraft in 

the planetary protection area. 

We also have another group where we reach out into the community and bring experts in to advise us on our curation. I had the 

opportunity just this past year to tour the facility down at Johnson. 

It’s extremely—it’s an amazing facility. It’s really fun to be able to 

go there and look at the Apollo lunar samples, the meteorites we’ve 

returned from Antarctica. And we take that facility, its preservation, and its eventual expansion as we move eventually towards 

bringing samples back from Mars. So we certainly work closely 

with the community to understand what is needed and to make 

sure we will eventually, when we do return samples from Mars, we 

will have a plan in place. 

Mr. BABIN. Thank you very much. 

And this is directed to everyone. What proportion of astrobiology 

research in the United States is funded directly or indirectly by 

NASA? Does anyone know? Okay. 

Dr. STOFAN. No. We at NASA can certainly take that question 

for the record. 

Mr. BABIN. Um-hum. 

Dr. STOFAN. I will say I was just talking with someone a few 

weeks ago. I was at a conference at Ames Research Center where 

we were thinking about climate on extrasolar planets, and it’s one 

of the reasons, as I mentioned in my testimony, that this whole 

area of astrobiology is an amazing one and it actually makes me 
55 

think it’ll be a little hard to pull the number out. We can certainly 

get you a number on the exact funding— 

Mr. BABIN. Okay. 

Dr. STOFAN. —but when you’re thinking about, for example, habitable conditions on stars, you have to be doing heliophysics to understand stars, the wind—that solar wind, the interior of the planet, does it have a magnetosphere that then protects that atmosphere from being stripped away? The work we do here on Earth to 

understand extremophiles, planetary science, we’re pulling from so 

many disciplines, which is to me what makes this area of science 

in particular so incredibly exciting and fruitful. It’s truly interdisciplinary. 

Mr. BABIN. Absolutely. Okay. And also what are the most important technological advancements that are needed to further 

astrobiology research and what advancements should be our highest priority to continue this? 

Dr. LUNINE. Well, I’ll take one crack at this. And I don’t want 

to prioritize these, but one in my area is to develop miniaturized 

instrumentation that can detect the chemical signs of life and also 

detect biological activity. The smaller the instruments, the easier 

it’s going to be to send them to the planets. 

Dr. BEAN. From the standpoint of studying exoplanets, I talked 

in my testimony about building a very large space telescope as a 

flagship mission. That’s a very high-tech thing that we have to do 

to take direct images of planets that we can take spectra from and 

look for the signatures of biosignature gases. That involves the construction of large space telescopes, rockets to put those telescopes 

into orbit, instrumentation to block the blinding glare of the stars 

those planets orbit, and perhaps even the manned spaceflight program to service those telescopes or even construct the telescopes in 

orbit. 

Mr. BABIN. Thank you. 

Dr. SIEMION. I think in the search for extraterrestrial intelligence, the low-hanging fruit is very much digital signal processing 

technology, so improving our ability to process the very, very high 

data rate streams that are produced by radio telescopes and some 

optical telescopes, and also developing receiver technology for radio 

telescopes that allow us to use old facilities in new ways. 

Mr. BABIN. Right, thank you. Mr. Chairman, I yield back the balance of my time. Thank you, panelists. 

Chairman SMITH. Thank you, Mr. Babin. 

The gentlewoman from Connecticut, Ms. Esty, is recognized for 

her questions. 

Ms. ESTY. Thank you, Mr. Chairman, and thank you, Ranking 

Member Johnson, for holding today’s fascinating hearing. And 

thank you to all of you. 

I joined millions of Americans on Sunday night watching the 

Blood Moon and a Blue Moon earlier this year, and I have to tell 

you, in the district like mine in Connecticut, schoolchildren are incredibly inspired and excited by these developments. And many of 

us here on this panel share a commitment to STEM education. And 

so it’s in part through that lens I would like to proceed with my 

questions. 
56 

Congratulations, Dr. Stofan, incredibly exciting announcement 

yesterday. And we look forward to understanding what that means. 

And as you can hear, we’ve already had questions today. 

Dr. Stofan, you spoke earlier about the need to have human exploration on Mars to really understand and to make those subtle 

intuitive judgments that are necessary. Do you anticipate that yesterday’s announcement and the discovery proceeding that changes 

in any way the priorities of the ordering of that? And help us understand our role as decision-makers on helping to set priorities 

that are keeping up with the developing science. 

Dr. STOFAN. You know, I think one of the most exciting things 

about yesterday is the fact that we now know there’s near-surface 

liquid water on Mars. And so this idea that Jonathan Lunine mentioned in his testimony of—you know, again, because of this length 

of water—time that we know that water was stable on Mars, that’s 

what makes scientists think that Mars is the place where life 

maybe could have evolved because not only did you have liquid 

water but you had the time to allow the chemical reactions to take 

place. 

The exciting thing about knowing there’s near-surface water is 

saying maybe there could still be life forms on Mars today deep underground, several meters below ground where the cosmic radiation 

that affects Mars would not affect them, but the idea that it’s potentially accessible to be studied by, again, astronauts and laboratories on the surface of Mars. And again, as a field geologist, somebody who likes to go out in the field and crack open rocks, I just 

have this strong bias that it’s going to take humans, laboratories 

a lot of work because, again, when you’re—it’s one thing if you’re 

looking for something large. If you’re looking for something small, 

it’s going to take time and it’s going to take effort, and that’s why 

I think humans are so critical. And that’s why NASA has chosen 

to be on this path. And I think the findings from yesterday convince us we’re on the correct path. 

Ms. ESTY. Thank you. And I have to confess I have a son who 

did astrophysics and did exoplanet things, so I have a personal— 

I know he has a personal interest in discovering if this manned 

mission is going to keep up with his fourth-grade project from, you 

know, about 15 years ago. 

Dr. Lunine, I was particularly struck by your comment that a 

key issue is whether in a habitable environment life actually does 

develop, which is sort of the opposite of where we start. We started 

with this search is there any life out there, and now it seems to 

me you’re asking a very different question, which is we see a lot 

of components that we would think ought to lead to life; does it 

lead to life or does it not? What are the technological breakthroughs you see us needing to support—to answer that somewhat 

different question? It seems to me that’s a different question than 

I certainly would have thought about five years ago. 

Dr. LUNINE. Well, it’s a different question but it’s a related question. We really have no laboratory model for how life began on the 

Earth. No one has done this in the laboratory. And so one of the 

reasons for going out to environments in our solar system where 

the conditions for life are apparently there and possible is to see 

whether life actually began, essentially to do the experiment in the 
57 

field instead of in the laboratory. And the critical things we need 

for that are devices to analyze abundances of amino acids, fatty 

acids, to look for patterns in other molecules that might be part of 

an exotic biochemistry, for example, on Titan. 

Part of the problem is that it’s not entirely clear what we want 

to look for in some environments. In other environments like Mars, 

Europa, Enceladus it’s very clear what we want to look for. So 

chemical analysis is critical and the ability to get out to these planets and sample planets and moons and sample them is also critical. 

Ms. ESTY. Thank you. And if we might be able to follow up afterwards with some more detail because, again, our job is in part to 

try to set funding priorities and they need to take into account 

these changes, so I think, Dr. Stofan, your comments about the 

near-surface presence of water compared with, say, Europa where 

it’s so deep and that presents harder technological challenges may 

help guide us with the—as I’m afraid we have to say the notenough money that we have to do this research. I wish we had 

more, but with what we have, we want to make sure it has the 

most impact and rely on your judgment in guiding us. Thank you 

all very much. 

Chairman SMITH. Um-hum. Thank you, Ms. Esty. 

The gentleman from Louisiana, Mr. Abraham, is recognized. 

Mr. ABRAHAM. Thank you, Mr. Chairman. 

I’m one of those teenagers that rushed home to see the original 

Star Trek with William Shatner and Leonard Nimoy, so this is fascinating. Like the Chairman said, we have a million questions. 

Dr. Stofan, like you, I’m of the opinion you’re going to have to 

have boots on the ground so to speak to finally answer the questions. So let’s bring it a little bit closer to home. You referenced the 

possible meteor asteroid in Antarctica. I’m assuming you’re referencing the Allan Hills meteor back in, what, ’84 I think it was 

when it was discovered. 

And if we go to a synthetic biology topics such as XNA as opposed to DNA, RNA, would our funding be more appropriate in a 

realistic term as to funding projects in that realm as opposed to, 

you know, something that maybe 100 years off as far as time travel 

or space travel is concerned? 

Dr. STOFAN. Well, I certainly think that this is a multi—as I 

said, it’s a so interdisciplinary that you really need a multipronged 

approach. And so I think that’s what NASA has developed by saying we do need boots on the ground. I personally think it’s achievable that we meet the President’s goal of getting humans in the 

Mars vicinity in the 2030s. I think it’s completely doable. And in 

the meantime of course continuing our robotic exploration like 

we’re doing with the Mars 2020, moving with the Europa mission 

to go and explore Europa. 

So I don’t think it’s an either/or; I think it’s an ‘‘and.’’ We need 

to do the technology research here on the ground. We need to do 

biological research, and certainly synthetic biology is an amazing 

expanding field at this point in time. But I think it’s all of those 

things together that help us move forward scientifically and help 

us refine scientific questions as we move forward. 

Mr. ABRAHAM. And you’ve got DARPA, you’ve got USAR MED 

you’ve got NASA, you’ve got all these agencies looking for other life 
58 

forms, doing research on genetic engineering and those types of 

deals. Is there any one agency that is spearheading or that these 

other agencies report to? Is there any hurding of the cat so to 

speak where this research can come under one big umbrella and 

people talk to other agencies and actually come up with some formulations? 

Dr. STOFAN. Well, I think in the area of astrobiology this is why 

community roadmaps like the Astrobiology Community Roadmap 

that is coming out this year—because in my mind, going to the 

community, whether it’s through the Decadal Survey process 

through the Academies, the astrobiology roadmap is going out to 

the community, who—in general, the scientists know where all the 

funding streams are coming from. They’re the ones who are truly 

pulling and doing this multidisciplinary work. So when you get the 

community together and say here are the priorities, here are the 

areas that we think have the most potential for advancement in 

the next five to ten years, it’s that voice of the scientific community 

that I think helps guide—— 

Mr. ABRAHAM. But is there one voice at this point or is anybody 

at the top of the heap so to speak? 

Dr. STOFAN. In astrobiology I would argue that NASA is really 

guiding what we’re doing and what the next steps are. We certainly 

work closely with other agencies, though. 

Mr. ABRAHAM. Does NASA have any rules or regulations that 

they foresee that would limit or harness this potential breakthrough? I mean I could see where with what we have available 

even now with some of the genetic engineering that, you know, 

some of this stuff could turn out to be kind of bad stuff. 

Dr. STOFAN. We certainly don’t have any regulatory authority 

but I’d have to take that question for the record because I don’t 

know the answer to it. 

Mr. ABRAHAM. Okay. Thank you. 

Dr. Lunine, just a quick comment on what you had spoken with 

the Congressman earlier about potential life developing in an environment. Just a personal question: What is your theory on 

panspermia, the bringing of life forms into our Earth atmosphere 

on an asteroid or meteor? 

Dr. LUNINE. I think that panspermia has occurred certainly between the Earth and Mars. We know that materials are exchanged 

between those two planets. We have the Allan Hills meteorite. And 

there are some good studies that have been done that show that 

amino acids will survive the trip to the Earth through the atmosphere on an asteroid and possibly bacteria as well, so there may 

well have been extensive exchange of life and biological materials 

between the Earth and Mars, particularly in the early history of 

the solar system when impacts were more frequent. 

Mr. ABRAHAM. Okay. Thank you, Mr. Chairman. I yield back. 

Chairman SMITH. Thank you, Mr. Abraham. 

The gentleman from Virginia, Mr. Beyer, is recognized. 

Mr. BEYER. Thank you, Mr. Chairman. I thank all of you for 

coming today. It’s a fascinating hearing. Mr. Chairman, thank you 

very much for structuring this. And I look forward to our Science, 

Space, and Technology CODEL for low-Earth orbit. I’m counting on 

you to assist me in this. 
59 

To go quickly, Dr. Siemion, you know, for years we had the PCs 

at our home following SETI, doing the analysis of the work, and 

it was fun. We have no successful conclusion yet. I’m fascinated by 

the $100 million for the Breakthrough project. But what happens 

when we discover extraterrestrial intelligence? Do we have a plan 

about what happens next? 

Dr. SIEMION. Well, I’ll just mention that—so SETI at home, the 

program on PCs, is still around and you’re all welcome to download 

it. It runs on cellular telephones now, as well as home PCs. 

I think a lot of people have put a lot of thought into what to do 

when we potentially eventually discover intelligent life or any kind 

of life beyond the Earth. I think there will be a range of reactions. 

I think for my part my personal opinion is that probably the most 

common reaction will sort of be I sort of—I told you so. I think 

many people probably believe that life is out there and maybe even 

intelligent life, and certainly the more we learn about the 

exoplanet population and water on Mars and these kinds of things 

I think reinforced with people the possibility. But the truth is is 

that we really don’t know for now, and I think to see what the reaction will actually be we’ll probably have to wait and see. 

Mr. BEYER. It’d be interesting to have protocols in place for when 

we finally get the breakthrough, what do we say back and the like 

so—yeah. 

And, Dr. Lunine, you talked about Titan and all the methane 

and ethane and all that, and I sort of basically understand that 

most elements only come from the explosion of stars, so you’ll get 

the carbon, but are methane and ethane—can they develop other 

than biologically? 

Dr. LUNINE. Yes. Actually, methane is a very simple organic molecule, and so it occurs in many environments, in interstellar clouds, 

in—they’re in comets. It’s measured there. And so these are evidently sources of methane that are not from biology. It’s simple to 

make in the laboratory, for example, and carbon is very abundant, 

as you alluded to, as one of the products of stellar nucleosynthesis. 

So we think that Titan is—has an enormous inventory of methane that is not biological, that was produced by abiotic sources. 

And the ethane that is also part of that system was produced from 

the methane, and that’s something that Cassini has confirmed for 

us by measuring the places in the atmosphere where the ethane is 

produced from the methane by ultraviolet chemistry. So Titan is a 

huge repository of abiotic methane. 

Now, from those and other organic molecules, does some form of 

life occur on the surface or arise in the seas of Titan? That’s the 

part we don’t know. 

Mr. BEYER. All right. Thank you. 

Dr. Stofan, I think this is for you but maybe Dr. Lunine. Dr. 

Abraham talked about the panspermia, and I know there was a 

project that evolved out of Harvard or MIT a few years ago trying 

to replicate the early origin of life on Earth, you know, the primordial soup, organic soup thing. Is there much evidence that—or 

any evidence that life on Earth may have started someplace else? 

Dr. STOFAN. You know, we just don’t know the answer to that. 

You know, we know—what we do know is that life evolved very 

rapidly here on Earth after conditions stabilized. And again, that’s 
60 

a factor that makes us optimistic that there’s life elsewhere in the 

solar system knowing that life arose relatively rapidly here. 

But we honestly don’t know if, again, did Mars—you know, bacteria come from Mars, bacteria from Earth go to Mars? We just 

don’t know that, and that’s why it’s so critical we think to continue 

this search for life on Mars, the other bodies of our solar system 

to answer that very question. 

Mr. BEYER. Great, thank you. 

Dr. Bean, you’re—it’s fascinating your photos of Enceladus and 

the fissure, and the—I was trying to—if you could go a little deeper 

on—are those gases that are being released from—through the fissure that—— 

Dr. BEAN. So I think that would be more appropriately addressed 

to Dr. Lunine if you want to— 

Mr. BEYER. Okay. Was it—I’m sorry. 

Dr. LUNINE. Yeah, that’s okay. I think it was my slide. So—— 

Mr. BEYER. Okay, great. 

Dr. LUNINE. —in the case of Enceladus, those fissures at the 

south pole have jets of gas and ice emanating from them, and those 

jets merged to make this a very large plume that was discovered 

by Cassini. We did not know of the existence of this plume until 

the Cassini mission. And once the plume was discovered, Cassini 

was directed to actually fly through the plume multiple times and 

sample the material in the plume with its instruments. One of the 

important lessons that we get from this is that these flagship missions with large numbers of instruments are able to respond very 

flexibly to new discoveries. The instruments actually tasted the 

material in the plume or designed it to sample the atmosphere of 

Titan, but once the plume was discovered, Cassini could actually 

use those same instruments to tell us what the plume is made of. 

Mr. BEYER. Okay, great. Thank you very much. Chairman, I 

yield back. 

Chairman SMITH. Thank you, Mr. Beyer. 

The gentleman from Florida, Mr. Posey, is recognized. 

Mr. POSEY. Thank you, Mr. Chairman, and thank the witnesses 

for their testimony today. 

I just wonder if each of you would give me your definition of life. 

Dr. STOFAN. I think it’s a something the scientific community 

really struggles with. You know, certainly there are signs that everybody agrees on, you know, something that is self-replicating, 

something that consumes a something and excretes something else, 

but the problem is life here on Earth, what we’ve learned from 

doing research here on Earth is that life and the boundary of 

what’s not life and what is life is a little blurry, and that’s why this 

is going to be so challenging to go find life on other planets. 

Dr. LUNINE. Life is a self-replicating system that undergoes evolution or mutation and which also seeks to minimize its local entropy, maximize its order in the sense that chemically we use a 

very small fraction of the possible compounds that can be produced 

from carbon, and the fact that we’re alive is because we can take 

in large amounts of nutrients, process them to make this very 

small, specific set of molecules that build our structure, control energy in and out, control the information needed to build these other 

molecules, and then we expel the rest. So for me as—with my phys-
61 

ics background, it’s a very high order, very low entropy in a chemical system. 

Dr. BEAN. I would say that astronomers use a very basic definition of life because the information that we can get when we study 

the atmospheres of exoplanets will also be very basic. And so we 

use a very Earth-centric, even human-centric point of view for life, 

and that’s the thing that we’re looking for evidence for in the 

atmospheres of other worlds. 

Dr. SIEMION. I guess there’s some advantage to going last on a 

question like that. I don’t know that I have a lot to add to what 

Dr. Stofan, Lunine, and Bean said. I certainly appreciate the thermodynamic definition of life that Dr. Lunine articulated. I guess 

maybe the only thing that I would add to that is that I think many 

of us in the astrobiology community assume that life is something 

that we’ll know when we see it, and hopefully that’s true, but we’re 

not sure. And it’s quite possible that the first life that we encounter 

beyond the Earth will be very different than any kind of life that 

we have on Earth. 

Mr. POSEY. Thank you. This question is for each of you. If you 

could pick a mission, this person would say I want a mission that 

will do this, achieve this, you know, what particular type of mission 

would you choose? 

Dr. STOFAN. You know, I’m going to go with the geologists on the 

surface of Mars looking—you know, cracking open lots of rocks 

looking for life. That’s my big payoff mission. 

Dr. LUNINE. So I would go with the Europa mission, and the reason for that is we have so much tantalizing evidence that Europa 

is a habitable environment but there are missing pieces, including 

whether there are organics and where to actually go search for life. 

And I personally—and I think we have been waiting since 1998 for 

a mission to follow up on the Galileo orbiter Discovery of the ocean 

under Europa. And so from my point of view I think it’s a critical 

mission to do and I would make that my number one right now. 

Dr. BEAN. So I would like to see a large space telescope that can 

take spectra of other Earth-like planets orbiting nearby stars, 

something very similar to the previously proposed and discussed 

Terrestrial Planet Finder mission, or TPF, which you may have 

heard about. I think the advantage of studying extrasolar planets 

is that we have a chance to look for—to do an experiment so to say 

on how life arises on terrestrial planets in a variety of environments. So that’s what I would like to see. 

Dr. SIEMION. I’m not sure what list I’m choosing from here, but 

as a radio astronomer and someone interested in SETI, I think it 

would—I’d be remiss to not suggest that it would be wonderful to 

put a radio telescope on the far side of the Moon. That region of 

the Moon is protected from radio frequency interference from the 

Earth, something that confuses us in SETI experiments and allows 

us to observe at very, very low frequencies very effectively. 

Mr. POSEY. Y’all make the choices really tough, don’t you? 

Following up on the last answer, some people think because 

we’ve been to the Moon, we shouldn’t return to the Moon. There’s 

some—obviously some strategic reasons for going there for future 

transportation as a steppingstone to Mars, but I’d like to ask each 
62 

of you your opinion of whether or not we still have a lot to learn 

from our own Moon? 

Dr. STOFAN. I chaired the Inner Planets Panel for the last Planetary Science Decadal Survey, and in—listed in the New Frontiers 

collapse of missions is a mission to look at the terrain around the 

south pole of the Moon where we think the lunar mantle has come 

very close to the surface to help us understand the origin of the 

Moon and what that tells us about the origin and evolution of our 

own planet. So scientifically, we certainly have lots of outstanding 

questions about the Moon that the scientific community has articulated through the Decadal Surveys. 

Dr. LUNINE. The Moon contains the geologic record of the first 2 

billion years of the history of the Earth, and that record has been 

more or less lost on the Earth because the Earth has been so active. And so that is for me the critical aspect of the scientific value 

of the Moon. That’s the time when life began on Earth, and to understand what was happening geologically, we can do no better 

than turn to the Moon. 

Dr. BEAN. I’d like to answer the question in terms of human 

spaceflight. Dr. Stofan and Dr. Lunine, you gave great scientific answers, but for me, if we can combine science with the human element, I think that’s a very powerful thing. That will reach out to 

the public. That will excite our schoolchildren to follow math and 

science, and so for me that’s an exciting ‘‘yes’’ to that question. 

Dr. SIEMION. I think I would agree with Dr. Bean. I think a 

manned mission to the Moon would be a wonderful steppingstone 

to future missions to perhaps Mars. 

Mr. POSEY. I want to thank y’all again for your testimony. It’s 

really been wonderful and I think everyone enjoyed it. 

Thank you, Mr. Chairman. 

Chairman SMITH. Thank you, Mr. Posey. 

The gentleman from California, Mr. Bera, is recognized for his 

questions. 

Mr. BERA. Thank you, Chairman, and Ranking Member. And I 

really want to thank both the Chairman and Ranking Member for 

this topic. You know, it comes at a very timely time—and the witnesses. 

You know, as a child growing up in Southern California at the 

heart of the aerospace industry in the ’60s and ’70s, you know, the 

space race captivated us, the Apollo missions, Apollo-Soyuz, Skylab, 

going to the space shuttle. And, you know, as someone who went 

into the sciences and became a doctor, you know, it really was pivotal in, you know, fostering our curiosity. I mean if we think about 

who we are as a race, as human beings, we are naturally curious. 

We are natural explorers and we want to find those answers. 

And I think it’s incredibly important, the work that NASA is 

doing, the work that our scientists are doing and fostering the 

imagination of the next generation. I think we need to do more of 

that in fact because, you know, in listening to some of the—your 

testimony, as well as how you answer the questions, we don’t know 

what life is going to look like. We don’t know what we are going 

to discover. We don’t know what frequencies we should be listening 

for. But we do know that something is out there, and if we don’t, 

you know, continue to push our imagination, if we don’t continue 
63 

to—we don’t know how we’re going to get to Mars, let alone how 

we’re going to send a human being to Mars and bring them back, 

but we do know if we challenge ourselves, we will discover that. We 

will—we always have. And I think that is the importance of what 

we’re doing here on the Science and Technology Committee but 

also in Congress and also working with our colleagues around this 

world because this is not just a U.S. mission; it is a human mission 

to find and discover, you know, where we came from, how life 

evolved, but also how life becomes extinct as well, as we’re looking 

at these planets, the impacts of those discoveries on, you know, 

what is affecting our own planet right now as we deal with climate 

change, as we deal with a changing atmosphere. Those discoveries 

will help us manage our own issues on our planet. 

I’ll ask a quick question of each of the panelists, and each of you 

can answer this. In explaining why it is important to search for life 

beyond our planet, beyond just the philosophical elements, if you 

were to explain this to an elementary school student or the public 

in general, how might you put why this is such an important endeavor? And we’ll start with Dr. Stofan. 

Dr. STOFAN. You know, I certainly always mention this fact, that 

ever since I think there have been people looking up at the sky, 

we’ve wondered are we alone, and so there is that huge philosophical piece. The other piece I like to talk about is, you know, 

when we find life, does it have RNA? Does it have DNA? Is its cell 

structure like our cell structure? And then how can we take that 

information and look back at life here on Earth and try to understand better how life here involved, what the conditions are? And 

so to me you do get a tremendous learning about life in general by 

finding life on other planets. 

Obviously also I try to point out to audiences if they don’t buy 

the science and the philosophy stuff, I try to point out to them that 

when we do great human endeavors, whether it’s, you know, exploring the Moon, building the next great telescope, we challenge 

technology. We bring good technology jobs to this country. We move 

this country forward in our reputation both internationally and at 

home. And I think there’s that inspiration part of just doing really 

hard things, accomplishing great things, which this country has 

demonstrated so ably that were so capable of. 

And I will say I also like to tell schoolchildren when I go and talk 

to them, I say oh, my gosh, you guys have so much work to do. We 

have 5,000 planets we need you to go study. You know, we’ve got 

entries and landings for humans on Mars. You guys better grow up 

and get to work. We need help. 

Mr. BERA. Great. 

Dr. LUNINE. This might be a philosophical answer so I apologize 

for violating the ground rule, but, you know, for the last 500 years 

we’ve lived in a kind of a Copernican worldview where the Earth 

was not the center of the universe or even the solar system; it’s a 

planet in the solar system. The Sun is not at the center of the galaxy; it’s just a common star in the galaxy. The galaxy is one of 

hundreds of billions of galaxies in the cosmos, and yet we are singular. I mean life and intelligent life and ourselves at the moment 

we know of no other form of life, intelligent life, and the Copernican worldview would say they’re all over the place. And it’s cru-
64 

cial to test that because if that turns out not to be the case, that’s 

going to shatter our worldview. 

Dr. BEAN. So my answer would be more along the lines—of 

course, those are excellent reasons why we want to do that, and 

finding out the answer would he absolutely fascinating and change 

our worldview. But I think also the process of doing it tells us a 

lot about ourselves, tells us about our hopes and dreams and about, 

you know, how we can work together as a country and as a society 

and the world. So for me I want to emphasize the process of looking for that answer, whatever the answer may be, if it’s a positive 

or a negative. But the process—through the process we find out a 

lot about ourselves. 

Dr. SIEMION. So I may be a bit biased but I think that life is the 

most interesting property of the universe, the idea that somehow 

in this largely mechanical universe that we live in, that we understand to great detail, some sort of an organism came to be that 

could question its own existence, that could wonder about the universe itself and where it came from. You know, if we don’t understand that, then I think we don’t understand perhaps one of the 

most fundamental properties of the universe that we live in, and 

so we must answer that question. 

Mr. BERA. Great. Thank you. 

Chairman SMITH. Thank you, Dr. Bera. And just to follow up on 

that question if other Members will allow me, just real quickly, yes 

or no, do you think intelligent life does exist elsewhere in the universe? Dr. Stofan? 

Dr. STOFAN. Maybe. 

Chairman SMITH. Okay. Dr. Lunine? 

Dr. LUNINE. Mr. Chairman, am I allowed to answer by saying I 

honestly don’t know? 

Chairman SMITH. No, that’s a legitimate answer. Members of 

Congress should give that more often themselves. Dr. Bean? 

Dr. BEAN. I don’t know either. 

Chairman SMITH. And Dr. Siemion? I’m not asking you if you 

know; I’m just asking you if you think. 

Dr. SIEMION. I also don’t know but I think it would be incredibly 

strange if we were the only example of intelligent life in the universe. And—— 

Chairman SMITH. Okay. 

Dr. SIEMION. —I’ll quote Stephen Hawking just very, very briefly, someone much smarter than I am. A universe in which intelligent life only exists in one place and a universe in which intelligent life potentially exists in many, many places are very, very 

different places. 

Chairman SMITH. Very good. Thank you, Dr. Siemion. 

We’ll go now to a gentleman from California, Mr. Swalwell, for 

his questions. 

Mr. SWALWELL. Thank you, Chair. And thank you to our panelists. Congratulations. I have to say it’s refreshing to have a hearing 

about something so big, so exciting and further than the eye can 

see, and so, you know, in Washington it gets quite frustrating here. 

It feels like we are so focused on just very small, incremental 

things and people at home get quite frustrated that that seems to 

rule the day here. But the work that you’re doing is so important, 
65 

so big, and will inspire so many future scientists. So congratulations. 

I had the opportunity to go with the Chairman and a few others 

to Antarctica. One of your colleagues, John Gunderson, joined us 

on a trip and he told us as we went through the McMurdo Dry Valleys, that that area—and he was excited to be on that trip and visit 

that area because it most closely resembled what we believe many 

of the parts of Mars to be. And so this discovery is another step 

forward in that effort. 

As far as the water that has been discovered, do we believe it 

could support life? Is it too salty? Do we know enough about its 

properties to make that conclusion yet? Dr. Stofan? 

Dr. STOFAN. It certainly makes us concerned that that water in 

particular had a lot of perchlorates in it and salts, and so based 

on—you know, and this is where everything we say—you know, 

based on what we know about life on Earth, that would not be a 

very habitable type of water. That being said, what we know about 

the Earth is like this. What could be is like that. So fundamentally 

we don’t know. 

Mr. SWALWELL. Great. Any other thoughts from the panelists on 

that question? 

Dr. LUNINE. Well, just very briefly, if I talk about the possibility 

of looking for exotic biochemistries on Titan, I’d better not say that 

life is impossible in the perchlorate solutions on Mars, which would 

be a lot easier to imagine the biochemistries. So, yes, terrestrial life 

as we know it, bacteria, et cetera, would all be sterilized by that 

solution. But is there a form of life that has evolved to live in that 

solution? That would be very interesting but not impossible. 

Mr. SWALWELL. And speaking of sterilizing, according to the New 

York Times, ‘‘NASA has no plans to examine closely any of these 

places which may contain water or could be potentially habitable 

places out of fear of contaminating them with Earth’s microbes.’’ So 

sterilizing probes is expensive. Do you think it’s time to reexamine 

this approach so we can follow up on this latest discovery? 

Dr. STOFAN. You know, I think the scientific community right 

now, not just in the United States but around the world is—you 

know, because obviously planetary protection is something that’s 

governed by international policies and procedures, we want to 

make sure that if we find life on Mars, we know that we’ve found 

life that is Martian life, not contamination we brought from the 

Earth. 

And so certainly in areas where there are water, we need to be 

cautious, extremely cautious as we move towards exploring them. 

However, those areas could potentially be the most interesting 

areas to explore. And so I think the scientific community is certainly going through a process right now of saying, okay, right now, 

we don’t think that’s the place to run to and potentially contaminate so let’s take a really measured, very scientific approach to how 

we might get at exploring those regions. Obviously, when we eventually send humans to Mars, that’s going to lead to much likely 

broader-scale contamination, and so I think it’s important as we 

lead up to sending humans to Mars we try to keep Mars as pristine 

as we can. 
66 

Mr. SWALWELL. Great. And finally, 38 million Californians are 

wondering: Can we get that water to California? 

Dr. STOFAN. Certainly the California drought is something that 

NASA is very concerned about. We’ve been using our satellites to 

do what we can to help to certainly monitor with the GRACE data. 

And we’ve certainly seen the alarming reduction in the amount of 

water in the aquifers. And we’ve been working on some projects 

with farmers in California that have—and some pilot projects that 

have reduced water usage by as much as 30 percent. So NASA is 

trying to help. 

Mr. SWALWELL. That’s great. Thank you. I yield back. Thank you, 

Chairman. 

Chairman SMITH. Thank you, Mr. Swalwell. 

The gentlewoman from Maryland, the Vice—excuse me, the 

Ranking Member of the Space Subcommittee is recognized for her 

questions. 

Ms. EDWARDS. Thank you very much, Mr. Chairman, and thank 

you to the members. 

I was sort of curious. I don’t know if Mr. Foster had a chance 

to—we were kind of speculating over here as to whether there’s 

value in doing the kind of marking of all of these different sources 

to determine whether there was at some point sort of one general 

dispersion so that there is a relationship between potential life that 

we might detect one place and another, and so I don’t know if that 

kind of work is going on. And I wondered, Dr. Lunine, if you could 

speak to that. 

Dr. LUNINE. Sure. I’d be happy to. I assume you’re talking about 

in our solar system? 

Ms. EDWARDS. Yes. 

Dr. LUNINE. So there’s been quite a lot of work done of course 

to understand how frequently material has been exchanged between the Earth and Mars, as I alluded to, but also for Europa, is 

it possible to get material from Europa to the Earth and vice versa? 

And then Enceladus and Titan. And the answer is that the farther 

out you go, the less likely it is. So the most recent studies that 

have been done, which are all computer models, say that the 

chance of cross contamination between the Saturn system and the 

Earth is very, very small, and the chance of contamination between 

Europa and the Earth is a little bit higher but still relatively small. 

So one of the advantages of going to the outer solar system, in 

addition to exploring Mars, is that we may be going to habitable 

environments which have not been contaminated by either the 

Earth or Mars, and so if we find life there or the signs of life, we 

have somewhat higher assurance that that life had an independent 

origin of life on Earth, which of course is one of the important 

questions. Could life have begun more than once in our own solar 

system? And that’s one of the attractions of going to the outer solar 

system. 

Ms. EDWARDS. So then that leads me to another question. And, 

Dr. Lunine and Dr. Bean, in a 2007 National Academies report 

called ‘‘The Limits of Organic Life in Planetary Systems,’’ there 

was a caution against searching for a model of life that’s based on 

the model that we know here on Earth and a conclusion that life 

is possible in forms different from those on Earth. And so I wonder 
67 

if you could talk to me about the recommendations that came from 

the report to further inform investigations to detect and identify 

possible forms of life and other planetary environments? 

And I think, Dr. Lunine, in your testimony, in your prepared 

statement you asked whether the seas of Titan should be included 

in our search for life because of the Titan’s use of methane as a 

working fluid in place of water? So I guess my question is to what 

extent would missions to Titan and other potentially habitable environments be able to investigate habitats of life forms that are different—that may be different from those on Earth? 

Dr. LUNINE. So the 2007 report came out very strongly in favor, 

as you noted, of looking in environments that had the general conditions for habitability: energy, liquid, organic molecules, and that 

if in fact those environments were found not to have a form of life, 

that that would tell us that there’s something indeed very special 

about liquid water. And so that was I think one of the recommendations, as I recall, of that report. 

The challenge of course is how to look for biochemistry in a 

methane/ethane liquid. What do we actually look for? There’s no 

guideline that terrestrial biology gives us except for the guideline 

that life will be very selective in the chemical compound that it 

uses for catalysts, for building structures, and so on. And so therefore, if we go back to Titan, for example, with a boat or a submarine or whatever to explore these seas, if we find that the organic molecules in the seas are just like what’s in the atmosphere, 

you know, basically everything, that’s not going to be very promising in terms of life. But if there’s a suite of particular molecules 

and structures that are made over and over again, then that might 

suggest that if not life itself, at least a chemical evolution toward 

life is happening in those seas. Beyond that, it’s hard to say very 

much because we have our one example of life on the Earth. 

Now, just very briefly, in places like Enceladus and Europa, 

which have very Earth-like environments, we would expect that 

many of the basic molecules that terrestrial life uses like amino 

acids, which are abundant in the cosmos, that we would see that 

in life in those environments. 

Ms. EDWARDS. Dr. Bean, in the time remaining. 

Dr. BEAN. Right. In the context of the search for life on 

extrasolar planets, astronomy, my field, is a very discovery-driven 

field. We want to build space telescopes and instruments that are 

designed to be able to answer a question and we inform, you know, 

the design of those instruments with what we know about on 

Earth. But we also know that we’re going to find unexpected things 

and so we want to have as flexible of instruments as possible and 

we want to make as complete a characterization of these planets 

as we can. 

Just to give you an example, the Hubble Space Telescope and the 

Spitzer Space Telescopes were never designed to look in the 

atmospheres of extrasolar planets, but that has become one of the 

most impactful things that those telescopes have done just because 

they were built with a suite of instruments that were very flexible. 

And so we have to benchmark our design for these instruments 

based on what we know, and what we know is limits of the Earth. 

But we also want to remain open-minded and flexible and do this 
68 

complete characterization of the planets to try to answer this question in as holistic away as possible. 

Ms. EDWARDS. And I’ve greatly exceeded my time. 

Chairman SMITH. Thank you, Ms. Edwards. 

The gentleman from Colorado is recognized for his questions not 

with trepidation but with curiosity and expectation because I’m 

never sure where he’s going to go with his questions. But he is recognized. 

Mr. PERLMUTTER. And, Mr. Chairman and to the Ranking Member, I’ve served on a lot of committees in the Congress, and this 

Committee is by far the most exciting, stimulating, energizing committee in the Congress. And as I’m sitting down here and looking 

up at the top row and reading Tennyson, ‘‘For I dipped into the future, far as human eye could see, saw the vision of the world, and 

all the wonder that would be.’’ Listening to you all, that’s what this 

is about. This is—this gives me goose bumps. The versatility of 

your instruments or your minds to say, you know what, this was 

really intended to do that but we could use it for this. And I just 

enjoy this Committee. 

So—and Dr. Bera talked about the challenge and the desire of 

all of us to explore. I mean I have some differences with the Chairman on prioritizing and actually funding because I see what you 

all do and your research and your service to be investments in the 

future, and that will pay for a long time to come. And I don’t think 

it’s a zero-sum game pitting the astronomers against the physicists 

and all that stuff. And I don’t think the Chairman does either, but 

I really would like to see us move forward obviously with the Orion 

project and get humans to Mars. 

And with that, I’m going to yield to my friend from Maryland for 

her questions. 

Ms. EDWARDS. And I thank the gentleman from Colorado. We 

pulled a fast one on the Chairman there. 

Dr. Stofan, I just had one question about how you’re planning to 

use the Astrobiology Roadmap that’s going to be released later this 

year and a year later than initially thought. Will it be a major vehicle that NASA is going to use to establish priority and—priorities? And then what kind of challenges did the agency face that 

caused a one-year delay to the issuance of the roadmap? 

Dr. STOFAN. The Astrobiology Roadmap that again will come out 

shortly, the reason that it’s taken longer is because this science is 

evolving so rapidly and how the scientific community looks at it, 

bringing in all these multiple disciplines that want to have a voice 

in astrobiology because you might have thought ten years ago if 

you’re a heliophysicist that nothing you do has anything to do with 

astrobiology. All of a sudden you say, wait, I can actually contribute. And so that’s been—the reason for the delay of the roadmap is we’ve just been trying to get the best science from the scientific community, get it properly reviewed, and get it out as soon 

as we can. And so we’re happy that it’s done and it’s about ready 

to go. 

How we use those roadmaps is—definitely comes in several different ways. Basically, when anybody then proposes to NASA, 

whether it’s to do research, to do a mission, they then say here’s 

how my mission that I’m proposing maybe to a competitive line at 
69 

NASA. Here’s how I’m consistent with the goals of what the community is saying. And then we can use that at NASA and say is 

this really high priority? Because we look to the community 

through these community roadmaps, through the decadal process 

to say what is the best science, what’s the latest science, the most 

up-to-date science, and then how can we use that to inform our decision-making? 

Ms. EDWARDS. So just really quickly, is there a plan to have the 

National Academies review the roadmap as well? 

Dr. STOFAN. I don’t know that. I can take that for the record. 

Ms. EDWARDS. All right. And with that, I will yield back to the 

gentleman from Colorado and just say I am—I do get a little bit 

concerned with these, you know, constant discoveries which are 

really great and we find incredibly fascinating, that the public then 

becomes numb to it in a way that would harm us in terms of making sure that you have the resources that you need. 

And with that, I yield back to the gentleman—— 

Mr. PERLMUTTER. Thanks. 

Ms. EDWARDS. —from Colorado. 

Mr. PERLMUTTER. And to the Chairman and the Ranking Member, the thing that I enjoy about this is we are so—looking so forward and towards the future. And tonight, I don’t know if you 

talked about The Martian or not, but the thing that is so fun about 

that book, one, he’s a wise guy; and two, in that book, it’s about 

problem-solving, whether it’s math or engineering or physics or biology. 

And that’s what is so enjoyable about this Committee and about 

the panels that come and speak to us because I see you all as looking to the future and solving problems, and I just thank you for 

that. And I thank the Chairman and the Ranking Member for this 

Committee because it gives me energy every time I come in here. 

Chairman SMITH. Thank you, Mr. Perlmutter. You actually beat 

me in quoting Alfred Lord Tennyson because I was going to end by 

doing that. However, just to add one more tidbit of information 

here, this quote that you see behind us on the wall is from a poem 

called Locksley Hall and of course written by Alfred Lord Tennyson 

who lived from 1809 to 1892. I have the entire poem right here. It’s 

multiple pages but that is a wonderful excerpt of it. 

That brings us to the end of our hearing, which was obviously 

informative and exciting to all of us. And let me just simply add 

that when we think that we’re somehow limited in what we might 

explore or what we might detect elsewhere in the cosmos, I think 

it’s helpful to remember that we here in the United States went 

from the Wright Brothers to Apollo in 66 years. In 1903 we had 

the Wright Brothers. We had two guys flying a contraption a couple hundred feet, 20 feet above the ground. Sixty-six years later, 

we had 12 people walking on the Moon over several years. And any 

country that can do that can certainly continue to explore and 

learn from that exploration, and who knows, maybe even detect 

some form of life elsewhere. 

So thank you all for being here, most enjoyable hearing, and I 

thank the Members who are here as well. And we stand adjourned. 

[Whereupon, at 11:42 a.m., the Committee was adjourned.] 

(71) 

Appendix I 

ANSWERS TO POST-HEARING QUESTIONS
72 

ANSWERS TO POST-HEARING QUESTIONS

Responses by Dr. Ellen Stofan 
73 
74 
75 
76 
77 
78 
79 
80 
81 
82 
83 
84 
85 
86 
87 

Responses by Dr. Jonathan Lunine 
88 
89 
90 
91 

Responses by Dr. Jacob Bean, 
92 
93 
94 
95 

Responses by Dr. Andrew Siemion 
96 
97 
98 

Æ