vania-janet/multiturn-rag-retrieval-data huggingface dataset:
Discovering Alien Oceans: Density – NASA's Europa Clipper
Discovering Alien Oceans: Density – NASA's Europa Clipper

NASA

Europa Clipper

Skip Navigation

menu

close modal

All Resources

Discovering Alien Oceans: Density

Scientists believe that Jupiter's icy moon, Europa, has a liquid-water ocean underneath its frozen surface. While we can’t see that ocean directly, we can use the mass and density of known substances to predict what exists underneath the surface. In this activity, students will use the fundamentals of density to propose a model for the interior structure of Europa.
View the full classroom activity on the JPL Education website ›

Additional Resources

Europa Up Close

Meet Europa Clipper

Participate

ENLARGE

Related

Europa Clipper's propulsion module arrives in its shipping container in the cleanroom receiving bay at the Johns Hopkins Applied Physics Laboratory.

Europa Clipper Propulsion Module

The images used for the base of this globe were chosen from coverage supplied by the Galileo solid-state imaging (SSI) camera and Voyager 1 and 2 spacecraft.

Europa Hemispherical Globes 

This artist's concept shows a simulated view from the surface of Jupiter's moon Europa. Europa's potentially rough, icy surface, tinged with reddish areas that scientists hope to learn more about, ...

Simulated View from Europa's Surface (Artist's Concept) 

This mosaic of a region in the northern hemisphere of Jupiter's moon, Europa, displays many of the features which are typical on the satellite's icy surface.

Double Ridges, Dark Spots, and Smooth Icy Plains on Europa 

Europa Clipper’s surface dust analyzer instrument is examined following delivery to JPL in September 2022.

Europa Clipper's Dust Analyzer Delivered to JPL

An engineer makes an electrical connection to the sensor head for Europa Clipper’s dust analyzer.

Assembling the Sensor Head for Europa Clipper's Dust Analyzer

Dark crisscrossing bands on Jupiter's moon Europa represent widespread disruption from fracturing and the possible eruption of gases and rocky material from the moon's interior in this four-frame m...

Dark Bands on Europa
NASA’s Juno Provides High-Definition Views of Europa’s Icy Shell - NASA
This annotated image of Europa’s surface from Juno’s SRU shows the location of a double ridge running east-west (blue box) with possible plume stains and the chaos feature the team calls “the Platypus” (orange box). These features hint at current surface activity and the presence of subsurface liquid water on the icy Jovian moon. 

A giant ocean is thought to reside below Europa’s icy exterior, and these surface features have been associated with “true polar wander,” a theory that Europa’s outer ice shell is essentially free-floating and moves.
“True polar wander occurs if Europa’s icy shell is decoupled from its rocky interior, resulting in high stress levels on the shell, which lead to predictable fracture patterns,” said Candy Hansen, a Juno co-investigator who leads planning for JunoCam at the Planetary Science Institute in Tucson, Arizona. “This is the first time that these fracture patterns have been mapped in the southern hemisphere, suggesting that true polar wander’s effect on Europa’s surface geology is more extensive than previously identified.”
The high-resolution JunoCam imagery has also been used to reclassify a formerly prominent surface feature from the Europa map.
“Crater Gwern is no more,” said Hansen. “What was once thought to be a 13-mile-wide impact crater — one of Europa’s few documented impact craters — Gwern was revealed in JunoCam data to be a set of intersecting ridges that created an oval shadow.”
The Platypus
Although all five Europa images from Juno are high-resolution, the image from the spacecraft’s black-and-white SRU offers the most detail. Designed to detect dim stars for navigation purposes, the SRU is sensitive to low light. To avoid over-illumination in the image, the team used the camera to snap the nightside of Europa while it was lit only by sunlight scattered off Jupiter (a phenomenon called “Jupiter-shine”).
This innovative approach to imaging allowed complex surface features to stand out, revealing intricate networks of cross-cutting ridges and dark stains from potential plumes of water vapor.
NASA’s Webb Finds Carbon Source on Surface of Jupiter’s Moon Europa - NASA
Back

MissionsSearch All NASA MissionsA to Z List of MissionsUpcoming Launches and LandingsSpaceships and RocketsCommunicating with MissionsArtemisJames Webb Space TelescopeHubble Space TelescopeInternational Space StationHumans in SpaceWhy Go to SpaceAstronauts HomeCommercial SpaceDestinationsSpaceships and RocketsLiving in SpaceEarth & ClimateExplore Earth ScienceClimate ChangeEarth, Our PlanetEarth Science in ActionEarth MultimediaEarth DataEarth Science ResearchersThe Solar SystemThe SunMercuryVenusEarthThe MoonMarsJupiterSaturnUranusNeptunePluto & Dwarf PlanetsAsteroids, Comets & MeteorsThe Kuiper BeltThe Oort CloudSkywatchingThe UniverseExoplanetsThe Search for Life in the UniverseStarsGalaxiesBlack HolesThe Big BangDark Energy & Dark MatterScienceEarth SciencePlanetary ScienceAstrophysics & Space ScienceThe Sun & HeliophysicsBiological & Physical SciencesLunar ScienceCitizen ScienceAstromaterialsAeronautics ResearchHuman Space Travel ResearchAeronauticsScience in the AirNASA AircraftFlight InnovationSupersonic FlightAir Traffic SolutionsGreen Aviation TechDrones & YouTechnologyTechnology Transfer & SpinoffsSpace Travel TechnologyTechnology Living in SpaceManufacturing and MaterialsRoboticsScience InstrumentsComputingLearning ResourcesFor Kids and StudentsFor EducatorsFor Colleges and UniversitiesFor ProfessionalsScience for EveryoneRequests for Exhibits, Artifacts, or SpeakersSTEM Engagement at NASAAbout NASANASA's ImpactsCenters and FacilitiesDirectoratesOrganizationsPeople of NASACareersInternshipsOur HistoryDoing Business with NASAGet InvolvedContactEspañolCienciaAeronáuticaCiencias TerrestresSistema SolarUniversoNews & EventsAll NASA NewsVideo Series on NASA+PodcastsBlogsNewslettersSocial MediaMedia ResourcesUpcoming Launches & LandingsVirtual EventsMultimediaNASA+ImagesNASA TVSounds and RingtonesInteractivesNASA AppsPodcastse-BooksSTEM Multimedia 

Highlights

 

5 min read

Clare Luckey: Shaping the Future of Mars Missions and Inspiring the Artemis Generation 

article

1 day ago
Instruments | Spacecraft – NASA's Europa Clipper
By collecting ultraviolet light with a telescope, and creating images, the mission’s ultraviolet spectrograph will help determine the composition of Europa’s atmospheric gases and surface materials. It will also search near Europa for signs of plume activity.
learn more ›

Mapping Imaging Spectrometer for Europa (MISE)

The mission’s infrared spectrometer will map the distribution of ices, salts, organics, and the warmest hotspots on Europa. The maps will help scientists understand the moon’s geologic history and determine if Europa’s suspected ocean is suitable for life.
learn more ›

Plasma and Magnetic Field
Plasma and Magnetic Field
Jupiter’s magnetic field, the largest in the solar system, traps the charged particle gas – plasma – that fills the space surrounding Europa (and the rest of the Jupiter system). As Europa moves in its orbit, the magnetic field varies. Time-variations of the magnetic field induce Europa to produce its own magnetic field that, in turn, will provide clues to the structure of the moon’s interior.

Europa Clipper Magnetometer (ECM)

The magnetometer investigation aims to confirm that Europa’s ocean exists, measure its depth and salinity, and measure the moon’s ice shell thickness. It will also study Europa’s ionized atmosphere and how it interacts with Jupiter’s ionized atmosphere.
learn more ›

Plasma Instrument for Magnetic Sounding (PIMS)

Europa’s ionosphere, and plasma trapped in Jupiter’s magnetic field, distort magnetic fields near Europa. PIMS Faraday cups will distinguish those distortions from Europa’s induced magnetic field, which carries information about Europa’s ocean.
learn more ›

Radar & Gravity
Radar & Gravity
Europa’s physical properties affect radio signals, which will help reveal the moon’s interior. A gravity experiment will analyze frequency shifts in the spacecraft’s signals to Earth (the same signals used in communication and navigation) to study Europa’s internal structure. A radar instrument will transmit radio into Europa’s icy shell and analyze the bounced signals to “see” internal features.

Gravity/Radio Science
NASA’s Juno Provides High-Definition Views of Europa’s Icy Shell - NASA
“These features hint at present-day surface activity and the presence of subsurface liquid water on Europa,” said Heidi Becker, lead co-investigator for the SRU at NASA’s Jet Propulsion Laboratory in Southern California, which also manages the mission. “The SRU’s image is a high-quality baseline for specific places NASA’s Europa Clipper mission and ESA’s (European Space Agency’s) Juice missions can target to search for signs of change and brine.”
Europa Clipper’s focus is on Europa — including investigating whether the icy moon could have conditions suitable for life. It is scheduled to launch on the fall of 2024 and arrive at Jupiter in 2030. Juice (Jupiter Icy Moons Explorer) launched on April 14, 2023. The ESA mission will reach Jupiter in July 2031 to study many targets (Jupiter’s three large icy moons, as well as fiery Io and smaller moons, along with the planet’s atmosphere, magnetosphere, and rings) with a special focus on Ganymede.
Juno executed its 61st close flyby of Jupiter on May 12. Its 62nd flyby of the gas giant, scheduled for June 13, includes an Io flyby at an altitude of about 18,200 miles (29,300 kilometers).
More About the Mission
JPL, a division of Caltech in Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of the Southwest Research Institute in San Antonio. Juno is part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington. The Italian Space Agency (ASI) funded the Jovian InfraRed Auroral Mapper. Lockheed Martin Space in Denver built and operates the spacecraft.
More information about Juno is available at:
https://www.nasa.gov/juno
News Media Contacts
DC AgleJet Propulsion Laboratory, Pasadena, Calif.818-393-9011agle@jpl.nasa.gov
NASA’s Juno Provides High-Definition Views of Europa’s Icy Shell - NASA
Although all five Europa images from Juno are high-resolution, the image from the spacecraft’s black-and-white SRU offers the most detail. Designed to detect dim stars for navigation purposes, the SRU is sensitive to low light. To avoid over-illumination in the image, the team used the camera to snap the nightside of Europa while it was lit only by sunlight scattered off Jupiter (a phenomenon called “Jupiter-shine”).
This innovative approach to imaging allowed complex surface features to stand out, revealing intricate networks of cross-cutting ridges and dark stains from potential plumes of water vapor. One intriguing feature, which covers an area 23 miles by 42 miles (37 kilometers by 67 kilometers), was nicknamed by the team “the Platypus” because of its shape.
Characterized by chaotic terrain with hummocks, prominent ridges, and dark reddish-brown material, the Platypus is the youngest feature in its neighborhood. Its northern “torso” and southern “bill” — connected by a fractured “neck” formation — interrupt the surrounding terrain with a lumpy matrix material containing numerous ice blocks that are 0.6 to 4.3 miles (1 to 7 kilometers) wide. Ridge formations collapse into the feature at the edges of the Platypus.
For the Juno team, these formations support the idea that Europa’s ice shell may give way in locations where pockets of briny water from the subsurface ocean are present beneath the surface.
About 31 miles (50 kilometers) north of the Platypus is a set of double ridges flanked by dark stains similar to features found elsewhere on Europa that scientists have hypothesized to be cryovolcanic plume deposits.
“These features hint at present-day surface activity and the presence of subsurface liquid water on Europa,” said Heidi Becker, lead co-investigator for the SRU at NASA’s Jet Propulsion Laboratory in Southern California, which also manages the mission. “The SRU’s image is a high-quality baseline for specific places NASA’s Europa Clipper mission and ESA’s (European Space Agency’s) Juice missions can target to search for signs of change and brine.”
Europa Glows: Radiation Does a Bright Number on Jupiter's Moon – NASA's Europa Clipper
To the naked eye, this glow would look sometimes slightly green, sometimes slightly blue or white and with varying degrees of brightness, depending on what material it is.
Scientists use a spectrometer to separate the light into wavelengths and connect the distinct "signatures," or spectra, to different compositions of ice. Most observations using a spectrometer on a moon like Europa are taken using reflected sunlight on the moon's dayside, but these new results illuminate what Europa would look like in the dark.
"We were able to predict that this nightside ice glow could provide additional information on Europa's surface composition. How that composition varies could give us clues about whether Europa harbors conditions suitable for life," said JPL's Murthy Gudipati, lead author of the work published Nov. 9 in Nature Astronomy.
That's because Europa holds a massive, global interior ocean that could percolate to the surface through the moon's thick crust of ice. By analyzing the surface, scientists can learn more about what lies beneath.
Shining a Light
Scientists have inferred from prior observations that Europa's surface could be made of a mix of ice and commonly known salts on Earth, such as magnesium sulfate (Epsom salt) and sodium chloride (table salt). The new research shows that incorporating those salts into water ice under Europa-like conditions and blasting it with radiation produces a glow.
That much was not a surprise. It's easy to imagine an irradiated surface glowing. Scientists know the shine is caused by energetic electrons penetrating the surface, energizing the molecules underneath. When those molecules relax, they release energy as visible light.
"But we never imagined that we would see what we ended up seeing," said JPL's Bryana Henderson, who co-authored the research. "When we tried new ice compositions, the glow looked different. And we all just stared at it for a while and then said, 'This is new, right? This is definitely a different glow?' So we pointed a spectrometer at it, and each type of ice had a different spectrum."
NASA’s Webb Finds Carbon Source on Surface of Jupiter’s Moon Europa - NASA
“We now think that we have observational evidence that the carbon we see on Europa’s surface came from the ocean. That’s not a trivial thing. Carbon is a biologically essential element,” added Samantha Trumbo of Cornell University in Ithaca, New York, lead author of the second paper analyzing these data.
NASA plans to launch its Europa Clipper spacecraft, which will perform dozens of close flybys of Europa to further investigate whether it could have conditions suitable for life, in October 2024.
A Surface-Ocean Connection
Webb finds that on Europa’s surface, carbon dioxide is most abundant in a region called Tara Regio – a geologically young area of generally resurfaced terrain known as “chaos terrain.” The surface ice has been disrupted, and there likely has been an exchange of material between the subsurface ocean and the icy surface.
“Previous observations from the Hubble Space Telescope show evidence for ocean-derived salt in Tara Regio,” explained Trumbo. “Now we’re seeing that carbon dioxide is heavily concentrated there as well. We think this implies that the carbon probably has its ultimate origin in the internal ocean.”
“Scientists are debating how much Europa’s ocean connects to its surface. I think that question has been a big driver of Europa exploration,” said Villanueva. “This suggests that we may be able to learn some basic things about the ocean’s composition even before we drill through the ice to get the full picture.”
Both teams identified the carbon dioxide using data from the integral field unit of Webb’s Near-Infrared Spectrograph (NIRSpec). This instrument mode provides spectra with a resolution of 200 x 200 miles (320 x 320 kilometers) on the surface of Europa, which has a diameter of 1,944 miles, allowing astronomers to determine where specific chemicals are located.
Carbon dioxide isn’t stable on Europa’s surface. Therefore, the scientists say it’s likely that it was supplied on a geologically recent timescale – a conclusion bolstered by its concentration in a region of young terrain.
Discovering Alien Oceans: Density – NASA's Europa Clipper
A view of the outward-facing side of the Europa Clipper vault plate.

Europa Clipper Vault Plate - Outward-Facing Side

The Europa Clipper Solar Array Mechanical Simulator is shown installed on the spacecraft’s propulsion module.

Solar Array Mechanical Simulator

Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft.

Sulfuric Acid on Europa 

Europa Clipper science team members at the eleventh science team meeting. 

Europa Clipper Science Team

This true-color simulated view of Jupiter is composed of 4 images taken by NASA's Cassini spacecraft on Dec. 7, 2000. 

High Resolution Globe of Jupiter 

Join team members from NASA’s Europa Clipper mission behind the scenes in a clean room at NASA’s Jet Propulsion Laboratory to learn about the design of this spacecraft that will visit Europa, an ic...

Spacecraft Makers: Introducing Europa Clipper

A JPL engineer holds one of four VHF radar antennas for Europa Clipper’s REASON instrument in its deployed configuration.

REASON VHF Radar Antenna

This animation shows a 360 of NASA’s Europa Clipper spacecraft. 

Mission Animation: Spacecraft 360

This view of Jupiter's moon Europa shows a portion of the surface that has been highly disrupted by fractures and ridges.

Ridges on Europa 

This colorized image of Europa is a product of clear-filter grayscale data from one orbit of NASA's Galileo spacecraft.

Reddish Bands on Europa

Stay Connected

Mission

Overview

Science

Timeline

The Team

History

FAQ

Spacecraft

Meet Europa Clipper

Instruments

Assembly

Vault Plate

Why Europa

Overview

Europa Up Close

Ingredients for Life

Evidence for an Ocean

News

Latest News

Mission Updates

Subscribe

Resources

All Resources

Images

Videos

Activities & Educational Resources

Posters, Stickers, & More

Participate

Participate

Feedback

|

Accessibility

Managed by the Jet Propulsion Laboratory
for
NASA’s Science Mission Directorate.

NASA Official/Program Executive: 
Dave Lavery

NASA Official/Program Scientist:
10 Things to Know About Europa Clipper's Science Instruments – NASA's Europa Clipper
…and a plasma instrument will study the flow of plasma near Europa, helping to calibrate data from the magnetometer. 
Jupiter’s magnetic field also carries charged particles in an ionized gas called plasma from the volcanic moon Io, Jupiter’s ionosphere, and Europa itself. This plasma distorts Europa’s induced magnetic field. The mission’s plasma instrument will study the density, temperature, and flow of plasma near Europa. The plasma instrument has four sensors called Faraday cups, which are metal cups designed to catch charged particles in space. Plasma creates an electrical current when it strikes a detector plate located within a Faraday cup, revealing the plasma’s speed and density. While interesting on its own, understanding the density, temperature, and flow of plasma will help calibrate data from the spacecraft’s magnetometer. The powerful combination of these two instruments is key to precisely determining Europa's ice shell thickness, and the depth and conductivity of its ocean.

Radio-frequency hardware, which will be used for gravity experiments, highlighted in red on the Europa Clipper spacecraft. 

6. Gravity experiments will also help determine the thickness of Europa’s ice shell. 
Finding out the thickness of Europa’s ice shell is important for understanding whether places exist below the moon’s surface that could support life today. Thinner ice or water passing through the ice would help essential chemical building blocks on Europa’s surface reach the ocean, improving the odds that the moon could sustain life. While the spacecraft’s ice-penetrating radar and magnetometer will provide complementary means of measuring the ice shell’s thickness, gravity experiments will also allow scientists to get detailed measurements of the varying shape of Europa’s surface as it orbits Jupiter as well as detailed information about Europa’s subsurface. 
+ read more

Europa Clipper will pass through Europa’s gravity field nearly 50 times while the moon is at various distances from Jupiter. Europa’s gravity field is in part a result of the shape of the moon itself. By studying how Europa’s gravity field changes shape, scientists are measuring how the moon itself responds to tidal forces by Jupiter, as a result of its interior structure.
Newly Reprocessed Images of Europa Show 'Chaos Terrain' in Crisp Detail
Three newly reprocessed images, taken by NASA's Galileo spacecraft in the late 1990s, reveal details in diverse surface features on Europa.Although the data captured by Galileo is more than two decades old, scientists are using modern image processing techniques to create new views of the moon's surface in preparation for the arrival of the Europa Clipper spacecraft. The orbiter of Jupiter will conduct dozens of flybys of Europa to learn more about the ocean beneath the moon's thick icy crust and how it interacts with the surface. The mission, set to launch in the next several years, will be the first return to Europa since Galileo."We've only seen a very small part of Europa's surface at this resolution. Europa Clipper will increase that immensely," said planetary geologist Cynthia Phillips of NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena. As a Europa project staff scientist, she oversees a long-term research project to reanalyze images of the moon. The above map shows locations where each image, showcasing a variety of features, was captured by Galileo during its eighth targeted flyby of Jupiter's moon Europa. Credit: NASA/JPL-Caltech The surface of Jupiter's moon Europa features a widely varied landscape, including ridges, bands, small rounded domes and disrupted spaces that geologists call "chaos terrain." Three newly reprocessed images, taken by NASA's Galileo spacecraft in the late 1990s, reveal details in diverse surface features on Europa.Although the data captured by Galileo is more than two decades old, scientists are using modern image processing techniques to create new views of the moon's surface in preparation for the arrival of the Europa Clipper spacecraft. The orbiter of Jupiter will conduct dozens of flybys of Europa to learn more about the ocean beneath the moon's thick icy crust and how it interacts with the surface. The mission, set to launch in the next several years, will be the first return to Europa since Galileo."We've only seen a very small part of Europa's surface at this resolution. Europa Clipper will increase that immensely," said planetary geologist Cynthia Phillips of NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena.