vania-janet/multiturn-rag-retrieval-data huggingface dataset:
NASA Astrophysics - NASA Science
Black holes are now known to be present at the center of most galaxies, including the Milky Way galaxy. The age, size and shape of the universe have been mapped based on the primordial radiation left by the big bang. And it has been learned that most of the matter in the universe is dark and invisible, and the universe is not only expanding, but accelerating in an unexpected way.For the long term future, the Astrophysics goals will be guided based on the results of the 2020 Decadal survey Pathways to Discovery in Astronomy and Astrophysics for the 2020s. It identifies the most compelling science goals and presents an ambitious program of ground- and space-based activities for future investment. The report recommends critical near-term actions to support the foundations of the profession as well as the technologies and tools needed to carry out the science.In 2012 the Astrophysics Implementation Plan was released which describes the activities currently being undertaken in response to the decadal survey recommendations within the current budgetary constraints. The plan was updated in 2014, 2016, and in 2018.The Astrophysics roadmap Enduring Quests, Daring Visions was developed by a task force of the Astrophysics Subcommittee (APS) in 2013.
What Is a Gravitational Wave? | NASA Space Place – NASA Science for Kids
Each LIGO observatory has two “arms” that are each more than 2 miles (4 kilometers) long. A passing gravitational wave causes the length of the arms to change slightly. The observatory uses lasers, mirrors, and extremely sensitive instruments to detect these tiny changes.
Watch the animation below to see how this works!

Related Resources for Educators

Modeling Gravitational Waves

Dropping In With Gravitational Waves

 	article last updated June 4, 2020
 

More about space!

What is a black hole?

What is the Big Bang?

What is a galaxy?

If you liked this, you may like:

What Is a Barycenter?

What Is Gravity?

Explore the Electromagnetic Spectrum

	 Games	 

	 Crafts	 

	 Activities	 

	 Videos	 

	 Glossary	 

	 Mystery	 

About Us
Privacy Policy
Image Use
Accessibility

Contact NASA Space Place

 Last Updated: May 6th, 2024 

 

More
Less

By Subject

Space
Sun
Earth
Solar System
People & Technology
Parents & Educators

By Type

Explore
Do
Play

More
Less

More about space!

What is a black hole?

What is the Big Bang?

What is a galaxy?
Gravitational Waves - Introduction
Gravitational waves are helping physicists and astronomers to understand some of the most fundamental laws of physics. They tell us about the dynamics of large-scale events in the universe like the formation and growth of galaxies and the supermassive black holes at their centers. With LISA, scientists will be able to probe through space and time, to observe the universe just a fraction of a second after the Big Bang. Using this information, we may be able to learn more about how the universe began and evolved.
Text updated: October 2017

 

 

 
 

 

 

A service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Andy Ptak (Director), within the Astrophysics Science Division (ASD) at NASA/GSFC

The Imagine Team
Project Leader: Dr. Barbara Mattson
Web Curator: J.D. Myers
Responsible NASA Official : Dr. Andy Ptak

Privacy Policy & Important Notices
Useful plugins
Contact Us
Page Last Updated: 11-Oct-2017
Overview | What is an Exoplanet? – Exoplanet Exploration: Planets Beyond our Solar System
Overview | What is an Exoplanet? – Exoplanet Exploration: Planets Beyond our Solar System

Opens in a new window
Opens an external site
Opens an external site in a new window

Toggle navigation
Close audio options
Play video
Close modal
Previous
Next
Toggle audio voice over
Toggle ambient music

NASA

Exoplanet Exploration

Skip Navigation

menu

close modal

What is an Exoplanet?

Overview

In Depth

Planet Types

Stars

What is the Universe?

MENU

Overview

In Depth

Planet Types

Stars

What is the Universe?

What is an exoplanet?

Fast facts

What is an exoplanet?

An exoplanet is any planet beyond our solar system. Most orbit other stars, but free-floating exoplanets, called rogue planets, orbit the galactic center and are untethered to any star.

Overview
Overview
Most of the exoplanets discovered so far are in a relatively small region of our galaxy, the Milky Way. We know from NASA’s Kepler Space Telescope that there are more planets than stars in the galaxy.
By measuring exoplanets’ sizes (diameters) and masses (weights), we can see compositions ranging from very rocky (like Earth and Venus) to very gas-rich (like Jupiter and Saturn). Exoplanets are made up of elements similar to those of the planets in our solar system, but their mixes of those elements may differ. Some planets may be dominated by water or ice, while others are dominated by iron or carbon. We’ve identified lava worlds covered in molten seas, puffy planets the density of Styrofoam and dense cores of planets still orbiting their stars.

There's a huge amount of variety among exoplanets – planets outside our solar system. There are water worlds, lava planets, egg-shaped worlds, planets with multiple suns, and even planets with no sun at all!
Types - NASA Science
Close to the black hole, a small fraction of the infalling gas can be driven outward, perpendicular to the disk, as jets of particles that move near the speed of light.During the early 20th century, astronomers began classifying active galaxies based on the distinctive characteristics and behaviors they observed. Scientists now think viewing the centers of these galaxies at different angles – for example, seeing directly into the torus versus seeing it from the side – produce many of the signature traits.Active galaxies can also be categorized by their brightness in radio wavelengths. Radio-loud galaxies typically emit from both the accretion disk and the jets. Radio-quiet galaxies tend to have little-to-no emission from jets. The observed luminosity is also thought to be another aspect of our viewing angle. Jets directed more toward our line of sight, viewed “down the barrel,” appear brighter and more variable than those viewed at wider angles.Seyfert GalaxiesThe Hubble Space Telescope captured this image of spiral galaxy NCG 5728, which is also a Seyfert-type active galaxy.ESA/Hubble, A. Riess et al., J. GreeneSeyfert galaxies, first identified in 1943 by American astronomer Carl Seyfert, are the most common active galaxies and also exhibit the lowest energies. All Seyferts look like normal galaxies in visible light, but they emit considerable infrared radiation. When observed in the infrared, some reveal bright emission from the donut-shaped torus. Some also emit X-rays. Seyfert galaxies tend to have lower radio luminosities, although some produce radio jets.Scientists divide Seyferts into two classes. Type I Seyfert galaxies display unusual features in their visible light that imply rapid motion near the accretion disk. Type II Seyferts show features that imply much slower motion.
Galaxies Actively Forming in Early Universe Caught Feeding on Cold Gas - NASA Science
This gas will likely end up fueling the formation of new stars in the galaxies.“These galaxies are like sparkling islands in a sea of otherwise neutral, opaque gas,” explained Kasper Heintz, the lead author and an assistant professor of astrophysics at the Cosmic Dawn Center (DAWN) at the University of Copenhagen in Denmark. “Without Webb, we would not be able to observe these very early galaxies, let alone learn so much about their formation.”“We’re moving away from a picture of galaxies as isolated ecosystems. At this stage in the history of the universe, galaxies are all intimately connected to the intergalactic medium with its filaments and structures of pristine gas,” added Simone Nielsen, a co-author and PhD student also based at DAWN.Image: Galaxy Forming in the Early Universe (Artist’s Concept)This illustration shows a galaxy forming only a few hundred million years after the big bang, when gas was a mix of transparent and opaque during the Era of Reionization. Data from NASA’s James Webb Space Telescope shows that cold gas is falling onto these galaxies.NASA, ESA, CSA, Joseph Olmsted (STScI)In Webb’s images, the galaxies look like faint red smudges, which is why extra data, known as spectra, were critical for the team’s conclusions. Those spectra show that light from these galaxies is being absorbed by large amounts of neutral hydrogen gas. “The gas must be very widespread and cover a very large fraction of the galaxy,” said Darach Watson, a co-author who is a professor at DAWN. “This suggests that we are seeing the assembly of neutral hydrogen gas into galaxies. That gas will go on to cool, clump, and form new stars.”The universe was a very different place several hundred million years after the big bang during a period known as the Era of Reionization. Gas between stars and galaxies was largely opaque. Gas throughout the universe only became fully transparent around 1 billion years after the big bang. Galaxies’ stars contributed to heating and ionizing the gas around them, causing the gas to eventually become completely transparent.By matching Webb’s data to models of star formation, the researchers also found that these galaxies primarily have populations of young stars.
Printed Product Downloads | NASA Space Place – NASA Science for Kids
The front is an infrared view of a ring of dust and gas at the center of the Milky Way galaxy that, with imagination, appears to be twisted into something like an infinity sign. Articles on back of poster explain the electromagnetic spectrum and how infrared astronomy reveals aspects of the universe not apparent in visible or other wavelengths of light. The poster includes a classroom version of Sir Frederick Herschel's 1800 experiment in which he discovers invisible infrared light. 
 Full-dimension .pdf of front and back (33 x 25.5 inches).
 8-1/2x11 printable .pdf of poster front and back pages.

The Art of space Imagery. The front is a mosaic of hundreds of thousands of frames of the Milky Way galaxy capture in infrared light by the Spitzer Space Telescope. On the back is a tutorial on how images captured in non-visible light are translated to visible light colors so that people can see, study, and enjoy them. 
 Full-dimension .pdf of poster (35 x 11 inches).

The Infrared Universe. The front is a montage of the different kinds of questions that infrared astronomy can address, regarding the cosmos, galaxies, star formation, star remains, and extrasolar planets. On the back are descriptions of how infrared astronomy works, why it is important, and some of the discoveries made so far. It also includes a classroom version of the Herschel experiment in which infrared light was discovered. 
 Full-dimension .pdf of poster (33 x 25.5 inches).

The Multiwavelength Universe. The front shows a composite image of the Pinwheel Galaxy that includes X-ray, ultraviolet, visible, and infrared light. Each wavelength reveals something different about the galaxy. The back of poster explains how different telescopes that detect different wavelengths are all necessary in order for us to begin to understand galaxies, stars, planets, and the evolution of the universe. 
 Full-dimension .pdf of poster (33.5 x 26 inches).

The North America Nebula. A stunning image in infrared and visible light shows a region of stars and dusty clouds that are hidden in visible light alone.
Imagine the Universe!
Imagine the Universe!

Skip navigation and go straight to page content. 
 
 

National Aeronautics and Space Administration
Goddard Space Flight Center

 
 

 
 
 

 

Home
Science

Astronomer's Toolbox
Cosmic Objects
Big Questions
Featured Science

Observatories

Learning Centers
Satellite Showcase
How Scientists Get Data
Detection Technology
History of High Energy Observatories

Special Exhibits

Coloring Pages
Scientist Profiles
You Be the Astrophysicist
Cosmic Distance Scale

Educators

Lesson Plans
Materials
Programs

Ask An Astrophysicist
Resources

Other Resources
Dictionary

Search

 
 
 

 

Ask an Astrophysicist
This is the "Ask an Astrophysicist" service of the Imagine the Universe! web site. We are a small group of volunteers who work on space-based astronomical observations, including cosmic-ray, gamma-ray, and X-ray astrophysics. Our research subjects are often exotic, like black holes, dark matter, and the origin of the universe.

We have already answered many questions, and have an extensive archive of past questions and answers. Please consult the archive first to see if your question has already been answered. We attempt to answer as many questions as possible, but we are a small group of volunteers and cannot afford the time to answer all the incoming questions.
We will not respond to questions whose answers may be found in our archive or on our site, or questions unrelated to space-based astrophysics.

We do not accept more than 1 question per email and no more than 1 question per week from an individual user.
Educators, please see Special Guidelines for Teachers.
It usually takes 1-2 weeks for our volunteers to answer a question.

Which topic area are you interested in?
(Please select one to search for the answer to your question)
♦ General Astronomy & Astrophysics *

Astronomy as a Profession
Binary Star Systems
Black Holes
Cosmic Rays
Cosmology
Dark Matter and Dark Energy
Earth and Moon (also calendars) *
Exoplanets
Gamma-ray Bursts
Milky Way and other Galaxies

Neutron Stars/Pulsars
Universe - NASA Science
Black HolesConcentrations of matter with gravity so powerful not even light can escape.GalaxiesCollections of stars, planets, and vast clouds of gas and dust bound together by gravity.The Search for LifeEarth is the only planet we know of with life on it ... so farThe Big BangLearn about he history of the universe according to cosmology’ current theoriesDark Matter and Dark EnergyMysterious substances that affect and shape the cosmos.The Universe StoriesExplore All Universe StoriesArticle2 min readHubble Captures a Bright Spiral in the Queen’s HairArticle5 min readGalaxies Actively Forming in Early Universe Caught Feeding on Cold Gas5 min readNASA’s TESS Finds Intriguing World Sized Between Earth, VenusArticle2 days ago6 min readNew Images From Euclid Mission Reveal Wide View of the Dark UniverseArticle2 days ago5 min readSpotted: ‘Death Star’ Black Holes in ActionImage ArticleReturn to topThe National Aeronautics and Space AdministrationNASA explores the unknown in air and space, innovates for the benefit of humanity, and inspires the world through discovery.About NASA's MissionJoin UsHomeNews & EventsMultimediaNASA+MissionsHumans in SpaceEarth & ClimateThe Solar SystemThe UniverseScienceAeronauticsTechnologyLearning ResourcesAbout NASANASA en EspañolFollow NASAMore NASA Social AccountsNASA NewslettersSitemapFor MediaPrivacy PolicyFOIANo FEAR ActOffice of the IGBudget & Annual ReportsAgency Financial ReportsContact NASAAccessibilityPage Last Updated:3 weeks agoPage Editor:SMD Content EditorsResponsible NASA Official for Science:Dana Bolles
Imagine the Universe!
These points are stable because centrifugal pseudo-forces work against gravity to cancel it out.
laser
Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. It's a device that produces a coherent beam of optical radiation by stimulating electronic, ionic, or molecular transitions to higher levels so that when they return to lower energy levels they emit energy.
LHEA
Laboratory for High Energy Astrophysics, located at NASA's Goddard Space Flight Center. The scientists, programmers and technicians working here study the astrophysics of objects which emit cosmic ray, x-ray and gamma-ray radiation.
light
The common term for electromagnetic radiation, usually referring to that portion visible to the human eye. However, other bands of the e-m spectrum are also often referred to as different forms of light.
light curve
A graph showing how the radiation from an object varies over time.

 Tell me about light curves

light year
A unit of length used in astronomy which equals the distance light travels in a year. At the rate of 300,000 kilometers per second (671 million miles per hour), 1 light-year is equivalent to 9.46053 x 1012 km, 5,880,000,000,000 miles or 63,240 AU (see scientific notation).
limb
The outer edge of the apparent disk of a celestial body.
LISA (Laser Interferometer Space Antenna)
A NASA mission which will detect gravitational waves. LISA will consist of three satellites that use laser interferometry to monitor their positions relative to each other. Gravitational waves passing by the satellites cause small changes in the distances between the satellites.

 Tell me more about LISA

luminosity
The rate at which a star or other object emits energy, usually in the form of electromagnetic radiation.

M
M0
A representation of the mass of an object in terms of Solar mass. The average mass of the Sun is about 2x1033 grams. Astronomers often express units for other objects in terms of solar units, since it makes the resulting numbers smaller and easier to deal with.
magnetic field
A description of the strength of the magnetic force exerted by an object.
NASA Astrophysics - NASA Science
Life in the UniverseStarsGalaxiesBlack HolesThe Big BangDark Matter &amp; Dark EnergyThe Solar System The SunMercuryVenusEarthThe MoonMarsJupiterSaturnUranusNeptunePluto &amp; Dwarf PlanetsAsteroids, Comets &amp; MeteorsThe Kuiper BeltThe Oort CloudSkywatchingEspañol CienciaAeronáuticaCiencias TerrestresSistema SolarUniversoScience All NASA ScienceEarth SciencePlanetary ScienceAstrophysics & Space ScienceThe Sun & HeliophysicsBiological & Physical SciencesLunar ScienceCitizen ScienceAstromaterialsAeronautics ResearchHuman Space Travel ResearchExploreSearchSubmitNews & EventsMultimediaNASA+HomeNASA AstrophysicsOverviewBig QuestionsOrganization and StaffFocus AreasDark Energy, Dark MatterBlack HolesThe Big BangGalaxiesStarsExoplanets ProgramsPrograms OverviewPhysics of the CosmosCosmic OriginsExoplanet ExplorationExplorersAstrophysics ResearchAstrophysics PioneersAstrophysics Division TechnologyHabitable Worlds Observatory Astrophysics Strategic Missions ProgramDataResourcesDocuments2020 Decadal SurveyAPD Responses to DecadalPre 2020 Decadal ReportsFleet ChartThe UniverseExplore This SectionOverviewFocus AreasProgramsDataResourcesThe UniverseNASA AstrophysicsIn the Science Mission Directorate (SMD), the Astrophysics Division studies the universe.The universe is everything. It includes all of space, matter, energy, time, and you.NASA’s Astrophysics Division is dedicated to exploring the universe, pushing the boundaries of what is known of the cosmos, and sharing its discoveries with the world. The Division continues expanding humanity’s understanding of how the universe began and evolved, how it works, and whether there are places beyond Earth where life might thrive.
Hubble Spots the Spider Galaxy - NASA Science
The first used Hubble’s Advanced Camera for Surveys to look at relatively nearby galaxies in an effort to build color versus brightness diagrams of the stars in these galaxies. Each observation only took one Hubble orbit (about 95 minutes) but provided a valuable archival record of the types of stars in different galaxies and therefore different environments.The second program used Hubble’s Wide Field Camera 3 to look at star clusters in dwarf galaxies. Their observations leveraged Hubble’s ultraviolet capabilities along with its ability to see fine details to better understand the environment where stars form in dwarf galaxies. The star-forming regions of UGC 5829 are readily visible in this image as bright-pink nebulae or clouds.Text credit: European Space Agency (ESA)Download this imageMedia Contact:Claire AndreoliNASA's Goddard Space Flight Center, Greenbelt, MDclaire.andreoli@nasa.govShareDetailsLast UpdatedMar 22, 2024EditorAndrea GianopoulosRelated TermsAstrophysicsGalaxiesGoddard Space Flight CenterHubble Space TelescopeIrregular GalaxiesMissionsThe UniverseKeep ExploringDiscover More Topics From NASAHubble Space TelescopeGalaxies StoriesStars StoriesNASA AstrophysicsReturn to topThe National Aeronautics and Space AdministrationNASA explores the unknown in air and space, innovates for the benefit of humanity, and inspires the world through discovery.About NASA's MissionJoin UsHomeNews & EventsMultimediaNASA+MissionsHumans in SpaceEarth & ClimateThe Solar SystemThe UniverseScienceAeronauticsTechnologyLearning ResourcesAbout NASANASA en EspañolFollow NASAMore NASA Social AccountsNASA NewslettersSitemapFor MediaPrivacy PolicyFOIANo FEAR ActOffice of the IGBudget & Annual ReportsAgency Financial ReportsContact NASAAccessibilityPage Last Updated:2 months agoPage Editor:SMD Content EditorsResponsible NASA Official for Science:Dana Bolles
Globular Cluster NGC 6355
NGC 6355 is a galactic globular cluster that resides in our Milky Way galaxy's inner regions. It is less than 50,000 light-years from Earth in the constellation Ophiuchus.

Globular clusters are stable, tightly bound groups of tens of thousands to millions of stars that are associated with all types of galaxies. Their dense populations of stars and mutual gravitational attraction give these clusters a roughly spherical shape that holds a bright, central concentration of stars surrounded by an increasingly sparse sprinkling of stars. The dense, bright core of NGC 6355 shines in crystal-clear detail as Hubble is able to resolve individual stars in the crowded area toward the center of this image.

For more information, visit: https://www.nasa.gov/image-feature/goddard/2023/hubble-gazes-at-colorful-cluster-of-scattered-starsCredits: ESA/Hubble & NASA, E. Noyola, R. Cohen Download Share Tags Hubble Space TelescopeTakenJanuary 2, 2023Image CreditESA/Hubble & NASA, E. Noyola, R. CohenSize640x377pxReturn to topThe National Aeronautics and Space AdministrationNASA explores the unknown in air and space, innovates for the benefit of humanity, and inspires the world through discovery.About NASA's MissionJoin UsHomeNews & EventsMultimediaNASA+MissionsHumans in SpaceEarth & ClimateThe Solar SystemThe UniverseScienceAeronauticsTechnologyLearning ResourcesAbout NASANASA en EspañolFollow NASAMore NASA Social AccountsNASA NewslettersSitemapFor MediaPrivacy PolicyFOIANo FEAR ActOffice of the IGBudget & Annual ReportsAgency Financial ReportsContact NASAAccessibilityPage Last Updated:10 months agoPage Editor:SMD Content EditorsResponsible NASA Official for Science:Dana Bolles