An exoplanet is a planet orbiting a star other than the Sun. Of particular interest are planets that may orbit in their star’s habitable zone, the distance from a star where temperatures allow liquid water to persist on a planet’s surface, given a suitable atmosphere. Since water is necessary for life as we know it, its presence is required for worlds to be considered capable of supporting life. Exoplanets can also teach us more about planets in the universe, such as the diversity of planets in the galaxy, how they interact with their host stars and with each other, and how common solar systems like ours really are. Using a wide variety of methods, astronomers have discovered more than 3,700 exoplanets to date, largely thanks to NASA's Kepler/K2 mission. Other NASA missions also play a key role in detecting exoplanets. The Transiting Exoplanet Survey Satellite, which launched in April 2018, will monitor 200,000 of the brightest dwarf stars for transiting exoplanets. Future missions like the James Webb Space Telescope will be able to study these discovered planets in greater detail, helping determine their composition. Researchers in NASA Goddard Space Flight Center's Sellers Exoplanet Environments Collaboration are leveraging work across disciplines to better understand exoplanets. Areas like planet-star interactions, planetary formation, and even study of the Earth itself enable researchers to develop tools to learn more about how exoplanets evolve, and what ingredients are necessary to support life.

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Artist's Illustrations

Artist's illustrations of exoplanets, NASA exoplanet missions, and detection methods. Includes animations and stills.
  • TESS Discovery Leads to Surprising Find of Promising World
    A planet discovered by NASA’s Transiting Exoplanet Survey Satellite (TESS) has pointed the way to additional worlds orbiting the same star, one of which is located in the star’s habitable zone. If made of rock, this planet may be around twice Earth’s size. The new worlds orbit a star named GJ 357, an M-type dwarf about one-third the Sun’s mass and size and about 40% cooler that our star. The system is located 31 light-years away in the constellation Hydra. In February, TESS cameras caught the star dimming slightly every 3.9 days, revealing the presence of a transiting exoplanet — a world beyond our solar system — that passes across the face of its star during every orbit and briefly dims the star’s light. The transits TESS observed belong to GJ 357 b, a planet about 22% larger than Earth. It orbits 11 times closer to its star than Mercury does our Sun. But while researchers were looking at ground-based data to confirm the existence of the hot Earth, they uncovered two additional worlds. The farthest-known planet, named GJ 357 d, is especially intriguing. The planet’s size and composition are unknown, but a rocky world with this mass would range from about one to two times Earth’s size. GJ 357 d is located within the outer edge of its star’s habitable zone, where it receives about the same amount of stellar energy from its star as Mars does from the Sun. If the planet has a dense atmosphere, which will take future studies to determine, it could trap enough heat to warm the planet and allow liquid water on its surface. GJ 357 c, the middle planet, has a mass at least 3.4 times Earth’s, orbits the star every 9.1 days at a distance a bit more than twice that of GJ 357 b. TESS did not observe transits from this planet, which suggests its orbit is slightly tilted — perhaps by less than 1 degree — relative to the hot Earth’s orbit, so it never passes across the star from our perspective.
  • TESS Discovers Its Tiniest World To Date
    NASA’s Transiting Exoplanet Survey Satellite (TESS) has discovered a world between the sizes of Mars and Earth orbiting a bright, cool, nearby star. The planet, called L 98-59b, marks the smallest found by TESS yet. Two other worlds orbit the same star. While all three planets’ sizes are known, further study with other telescopes will be needed to determine if they have atmospheres and, if so, which gases are present. The L 98-59 worlds nearly double the number of small exoplanets — that is, planets beyond our solar system — that have the best potential for this kind of follow-up. L 98-59b is around 80% Earth’s size and about 10% smaller than the previous record holder discovered by TESS. Its host star, L 98-59, is an M dwarf about one-third the mass of the Sun and lies about 35 light-years away in the southern constellation Volans. While L 98-59b is a record for TESS, even smaller planets have been discovered in data collected by NASA’s Kepler satellite, including Kepler-37b, which is only 20% larger than the Moon. The two other worlds in the system, L 98-59c and L 98-59d, are respectively around 1.4 and 1.6 times Earth’s size. All three were discovered by TESS using transits, periodic dips in the star’s brightness caused when each planet passes in front of it.
  • Exoplanet HD 21749 c Animation
    NASA’s Transiting Exoplanet Survey Satellite (TESS) has discovered its first Earth-size world, named HD 21749 c. It’s about 89% of Earth’s size and orbits HD 21749, a K-type star with about 70% of the Sun’s mass located 53 light-years away in the southern constellation Reticulum, and is the second planet TESS has identified in the system. The new world is likely rocky and circles very close to its star, completing one orbit in just under eight days. The planet’s surface is likely very hot, with temperatures perhaps as high as 800 F (427 C). HD 21749 c's host star is bright and relatively nearby, and is therefore well suited to more detailed follow-up studies, which could provide critical information about the planet’s properties.
  • Animations of TESS's First Exoplanets
    Illustration of the exoplanet LHS 3844 b. It is a rocky planet about 1.3 times Earth’s size located about 49 light-years away in the constellation Indus, making it among the closest transiting exoplanets known. The star is a cool M-type dwarf star about one-fifth the size of our Sun. Completing an orbit every 11 hours, the planet lies so close to its star that some of its rocky surface on the daytime side may form pools of molten lava.

    Credit: NASA/MIT/TESS

  • Exoplanet Animations
    Animation imagining what an ice-covered exoplanet might look like.
  • HD 189733b Exoplanet Animation
    The exoplanet HD 189733b lies so near its star that it completes an orbit every 2.2 days. In late 2011, NASA's Hubble Space Telescope found that the planet's upper atmosphere was streaming away at speeds exceeding 300,000 mph. Just before the Hubble observation, NASA's Swift detected the star blasting out a strong X-ray flare, one powerful enough to blow away part of the planet's atmosphere.
  • Exoplanet scale
    This illustration compares the sizes of various exoplanets with Earth and the Moon.

    Credit: NASA's Goddard Space Flight Center

  • TESS Spacecraft Animations
    The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey of the solar neighborhood, TESS will monitor more than 200,000 stars for temporary drops in brightness caused by planetary transits. This first-ever spaceborne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances. No ground-based survey can achieve this feat.
  • TESS Coverage Animations
    Animation showing the TESS spacecraft and the coverage of its four cameras. Each camera covers a 24 degrees-square patch of sky and the four cameras are arranged in a vertical strip called an observation sector.
  • TESS-Kepler Field-of-View Animation
    This animation begins with Kepler's first observation zone and the constellation Cygnus. It adds a single TESS camera field for comparison, and then pulls back to show all four TESS camera fields--called an observation sector--and the amount of sky they cover. The sphere of the sky unwraps into a flat projection and all the regions observed by Kepler appear. TESS's full 2 year coverage appears, starting in the southern hemisphere and ending in the northern. Finally, the map is rewrapped into a sphere.

    Credit: NASA/JPL-Caltech/T. Pyle (IPAC)

  • TESS Artist Concept Images
    Artist concept images of the Transiting Exoplanet Survey Satellite.
  • TESS Beauty Pass Animation
    The Transiting Exoplanet Survey Satellite (TESS) is an Explorer-class planet finder. In the first-ever spaceborne all-sky transit survey, TESS will identify planets ranging from Earth-sized to gas giants, orbiting a wide range of stellar types and orbital distances. The principal goal of the TESS mission is to detect small planets with bright host stars in the solar neighborhood, so that detailed characterizations of the planets and their atmospheres can be performed.
  • WFIRST Updated Spacecraft Beauty Pass Animations
    Animation video and stills based off the Mission Concept Review (MCR) design of the WFIRST spacecraft.
  • WFIRST MCR Spacecraft Animations
    Articulated spin of spacecraft in "warehouse" setting with human silhouette for scale.
  • Gravitational Microlensing Animation
    Gravitational microlensing is an observational effect that was predicted in 1936 by Einstein using his General Theory of Relativity. When one star in the sky appears to pass nearly in front of another, the light rays of the background source star become bent due to the gravitational "attraction" of the foreground star. This star is then a virtual magnifying glass, amplifying the brightness of the background source star, so we refer to the foreground star as the lens star. If the lens star harbors a planetary system, then those planets can also act as lenses, each one producing a short deviation in the brightness of the source. Thus we discover the presence of each exoplanet, and measure its mass and separation from its star. This technique will tell us how common Earth- like planets are, and will guide the design of future exoplanet imaging missions. More than 20 planets have been discovered from the ground using this technique. The WFIRST microlensing survey will detect many more such planets, including smaller mass planets since the planet "spike" will be far more likely to be observed from a space-based platform. This will lead to a statistical census of exoplanets with masses greater than a tenth of the Earth's mass from the outer habitable zone out to free floating planets. The results from the WFIRST microlensing survey will complement the exoplanet statistics from Kepler, and will provide answers to questions about planet formation, evolution, and the prevalence of planets in the galaxy.
  • WFIRST Coronagraph Animation
    A coronagraph works by blocking the bright light of a star to allower dimmer objects, like orbiting exoplanets, to become visible. This in turn allows cameras to directly image the exoplanet. Direct imaging provides the critical approach to studying the detailed properties of exoplanets. Images and spectra of directly imaged planets provide some of the most powerful information about the structure, composition, and physics of planetary atmospheres. This information can in turn help scientists better understand the origin and evolution of these systems. The direct imaging technique is also naturally applicable to the nearest and brightest, and thus best-characterized, solar systems. Advancing the technology for direct imaging of exoplanets was the top priority medium-scale space investment recommended by NWNH. Coronagraphy on WFIRST will be a major step towards the long-term goal of a mission that can image habitable Earth-mass planets around nearby stars and measure their spectra for signs of life.
  • WFIRST Milky Way Exoplanet Locations Animation
    The first exoplanets to be discovered were gas giants, but today it is becoming clear that there are probably many more "small" planets, in the Earth to Super-Earth range, than there are giants. Discovering the statistics of these planets is crucial for understanding their formation and commonality. Gravitational microlensing is a method of finding exoplanets by watching for when their gravity slightly magnifies the light from background stars. This technique will tell us how common Earth- like planets are, and will guide the design of future exoplanet imaging missions. More than 20 planets have been discovered from the ground using this technique. The WFIRST microlensing survey will detect many more such planets, including smaller mass planets since the planet "spike" will be far more likely to be observed from a space-based platform. This will lead to a statistical census of exoplanets with masses greater than a tenth of the Earth's mass from the outer habitable zone out to free floating planets. The results from the WFIRST microlensing survey will complement the exoplanet statistics from Kepler, and will provide answers to questions about planet formation, evolution, and the prevalence of planets in the galaxy.
  • Pluto's Underground Ocean
    Pluto and Charon may keep their interiors warm enough to support liquid water oceans.
  • Planets of Red Dwarf Stars May Face Oxygen Loss in Habitable Zones
    The search for life beyond Earth starts in habitable zones, the regions around stars where conditions could potentially allow liquid water – which is essential for life as we know it – to pool on a planet’s surface. New NASA research suggests some of these zones might not actually be able to support life due to frequent stellar eruptions – which spew huge amounts of stellar material and radiation out into space – from young red dwarf stars. Now, an interdisciplinary team of NASA scientists wants to expand how habitable zones are defined, taking into account the impact of stellar activity, which can threaten an exoplanet’s atmosphere with oxygen loss. This research was published in The Astrophysical Journal Letters on Feb. 6, 2017. To determine a star’s habitable zone, scientists have traditionally considered how much heat the star emits. Stars more massive than our sun produce more heat and light, so the habitable zone must be farther out. Smaller, cooler stars yield close-in habitable zones. But along with heat and visible light, stars emit X-ray and ultraviolet radiation, and produce stellar eruptions such as flares and coronal mass ejections – collectively called space weather. One possible effect of this radiation is atmospheric erosion, in which high-energy particles drag atmospheric molecules – such as hydrogen and oxygen, the two ingredients for water – out into space. Airapetian and his team's new model for habitable zones now takes this effect into account. The search for habitable planets often hones in on red dwarfs, as these are the coolest, smallest and most numerous stars in the universe – and therefore relatively amenable to small planet detection. Because these stars undergo little change over many billions of years, any habitable planets around them would enjoy stable conditions thought to be conducive to the development of life.
  • Hubble Detects "Sunscreen" Layer on Distant Planet
    Using NASA’s Hubble Space Telescope, scientists have detected a stratosphere, one of the primary layers of Earth’s atmosphere, on a massive and blazing-hot exoplanet known as WASP-33b. The presence of a stratosphere can provide clues about the composition of a planet and how it formed. This atmospheric layer includes molecules that absorb ultraviolet and visible light, acting as a kind of “sunscreen” for the planet it surrounds. Until now, scientists were uncertain whether these molecules would be found in the atmospheres of large, extremely hot planets in other star systems.
    Learn more on NASA.gov.
  • Mercury Transit May 9, 2016
    This animation shows the May 9, 2016 transit of Mercury across the face of the Sun.
  • Mars Transition
    Billions of years ago when the Red Planet was young, it appears to have had a thick atmosphere that was warm enough to support oceans of liquid water – a critical ingredient for life. The animation shows how the surface of Mars might have appeared during this ancient clement period, beginning with a flyover of a Martian lake. The artist's concept is based on evidence that Mars was once very different. Rapidly moving clouds suggest the passage of time, and the shift from a warm and wet to a cold and dry climate is shown as the animation progresses. The lakes dry up, while the atmosphere gradually transitions from Earthlike blue skies to the dusty pink and tan hues seen on Mars today.
  • Astronomers Directly Image Jovian Planet Around GJ 504
    Using infrared data from the Subaru Telescope in Hawaii, an international team of astronomers has imaged a giant planet around the bright star GJ 504. Several times the mass of Jupiter and similar in size, the new world, dubbed GJ 504b, is the lowest-mass planet ever detected around a star like the sun using direct imaging techniques.

    If we could travel to this giant planet, we would see a world still glowing from the heat of its formation with a color reminiscent of a dark cherry blossom, a dull magenta.

    GJ 504b orbits its star at nearly nine times the distance Jupiter orbits the sun, which poses a challenge to theoretical ideas of how giant planets form.

    According to the most widely accepted picture, called the core-accretion model, Jupiter-like planets get their start in the gas-rich debris disk that surrounds a young star. A core produced by collisions among asteroids and comets provides a seed, and when this core reaches sufficient mass, its gravitational pull rapidly attracts gas from the disk to form the planet.

    While this model works fine for planets out to where Neptune orbits, about 30 times Earth's average distance from the sun (30 astronomical units, or AU), it's more problematic for worlds located farther from their stars. GJ 504b lies at a projected distance of 43.5 AU from its star; the actual distance depends on how the system tips to our line of sight, which is not precisely known.

    The research is part of the Strategic Explorations of Exoplanets and Disks with Subaru (SEEDS), a project to directly image extrasolar planets and protoplanetary disks around several hundred nearby stars using the Subaru Telescope on Mauna Kea, Hawaii. The five-year project began in 2009 and is led by Motohide Tamura at the National Astronomical Observatory of Japan (NAOJ).

    While direct imaging is arguably the most important technique for observing planets around other stars, it is also the most challenging.

    The SEEDS project images at near-infrared wavelengths with the help of the telescope's novel adaptive optics system, which compensates for the smearing effects of Earth's atmosphere, and two instruments: the High Contrast Instrument for the Subaru Next Generation Adaptive Optics and the InfraRed Camera and Spectrograph. The combination allows the team to push the boundary of direct imaging toward fainter planets.

    GJ 504b is about four times more massive than Jupiter and has an effective temperature of about 460 degrees Fahrenheit (237 Celsius). It orbits the G0-type star GJ 504, which is slightly hotter than the sun and is faintly visible to the unaided eye in the constellation Virgo. The star lies 57 light-years away and the team estimates the system is about 160 million years old, based on methods that link the star's color and rotation period to its age.

  • Astronomers Directly Image a Massive Star's 'Super-Jupiter'
    Astronomers using infrared data from the Subaru Telescope in Hawaii have discovered a "super-Jupiter" around the bright star Kappa Andromedae, which now holds the record for the most massive star known to host a directly imaged planet or lightweight brown dwarf companion.

    Designated Kappa Andromedae b (Kappa And b, for short), the new object has a mass about 12.8 times greater than Jupiter's. This places it teetering on the dividing line that separates the most massive planets from the lowest-mass brown dwarfs. That ambiguity is one of the object's charms, say researchers, who call it a super-Jupiter to embrace both possibilities.

    Direct imaging of exoplanets is rare because the dim objects are usually lost in the star's brilliant glare. Massive planets slowly radiate the heat leftover from their own formation. For example, the planet Jupiter emits about twice the energy it receives from the sun. But if the object is massive enough, it's able to produce energy internally by fusing a heavy form of hydrogen called deuterium. (Stars like the sun, on the other hand, produce energy through a similar process that fuses the lighter and much more common form of hydrogen.) The theoretical mass where deuterium fusion can occur — about 13 Jupiters — marks the lowest possible mass for a brown dwarf.

    Young star systems are attractive targets for direct exoplanet imaging because young planets have not been around long enough to lose much of the heat from their formation, which enhances their brightness in the infrared. The team focused on the star Kappa And because of its relative youth — estimated at the tender age of 30 million years, or just 0.7 percent the age of our solar system, based on its likely membership in a stellar group known as the Columba Association. The star is located 170 light-years away in the direction of the constellation Andromeda and is visible to the unaided eye.

    Kappa And b orbits its star at a projected distance of 55 times Earth's average distance from the sun and about 1.8 times as far as Neptune; the actual distance depends on how the system is oriented to our line of sight, which is not precisely known. The object has a temperature of about 2,600 degrees Fahrenheit (1,400 Celsius) and would appear bright red if seen up close by the human eye.

    Carson's team detected the object in independent observations at four different infrared wavelengths in January and July of this year. Comparing the two images taken half a year apart showed that Kappa And b exhibits the same motion across the sky as its host star, which proves that the two objects are gravitationally bound and traveling together through space. Comparing the brightness of the super-Jupiter between different wavelengths revealed infrared colors similar to those observed in the handful of other gas giant planets successfully imaged around stars.

    The research is part of the Strategic Explorations of Exoplanets and Disks with Subaru (SEEDS), a five-year effort to directly image extrasolar planets and protoplanetary disks around several hundred nearby stars using the Subaru Telescope on Mauna Kea, Hawaii. The SEEDS research team is continuing to study Kappa And b to better understand the chemistry of its atmosphere, constrain its orbit, and search for possible secondary planets.

  • Debris Disks Make Patterns Without Planets
    A study by NASA scientists sounds a cautionary note in interpreting rings and spiral arms as signposts for new planets. Thanks to interactions between gas and dust, a debris disk may, under the right conditions, produce narrow rings on its own, no planets needed.

    Many young stars known to host planets also possess disks containing dust and icy grains, particles produced by collisions among asteroids and comets also orbiting the star. These debris disks often show sharply defined rings or spiral patterns, features that could signal the presence of orbiting planets. Astronomers study the structures as a way to better understand the physical properties of known planets and possibly uncover new ones.

    When the mass of gas is roughly equal to the mass of dust, the two interact in a way that leads to clumping in the dust and the formation of patterns. Effectively, the gas shepherds the dust into the kinds of structures astronomers would expect to see if a planet were present.

    Lyra and Kuchner refer to this as the photoelectric instability and developed a simulation to explore its effects. This animation shows how the process alters the density of dust in a debris disk and rapidly leads to the formation of rings, arcs and oval structures.

  • Spiral Arms Point to Possible Planets in a Star's Dusty Disk
    A new image of the disk of gas and dust around a sun-like star is the first to show spiral-arm-like structures. These features may provide clues to the presence of embedded but as-yet-unseen planets.

    The newly imaged disk surrounds SAO 206462, an 8.7-magnitude star located about 456 light-years away in the constellation Lupus. Astronomers estimate that the system is only about 9 million years old. The gas-rich disk spans some 14 billion miles, which is more than twice the size of Pluto's orbit in our own solar system.

    The Subaru near-infrared image reveals a pair of spiral features arcing along the outer disk. Theoretical models show that a single embedded planet may produce a spiral arm on each side of a disk. The structures around SAO 206462 do not form a matched pair, suggesting the presence of two unseen worlds, one for each arm.

Research Model Visualizations

Visualizations of exoplanets and models. Based on real data from modeling tools and/or missions. Learn more about the latest exoplanet modeling tools.
  • Exoplanet Disks In Formation
    These visualizations were developed using a simulation run from the SMACK (Superparticle-Method Algorithm for Collisions in Kuiper belts) code.
  • Exploring Exoplanet Parameters
    A presentation by Rachel Akeson at AAS in January 2015
  • Kepler Stares at Neptune
    The Kepler spacecraft, launched in March of 2009, is a telescope designed to search for exoplanets, planets orbiting stars other than our sun. It does this by continuously measuring the brightness of over 100,000 stars, waiting for momentary dimming that might indicate a planet has crossed in front of its host star. Scientists can infer the size and orbital period of an exoplanet from the depth and frequency of such dips in the star's light curve. For the first four years of the mission, Kepler stared at a single 12° patch of the sky between the bright stars Deneb, in the constellation Cygnus, and Vega, in Lyra, where it found several thousand exoplanet candidates. But when the second of the spacecraft's four reaction wheels failed in 2013, Kepler was no longer able to point accurately at its original target, so scientists devised a new way to point the spacecraft using the remaining two reaction wheels and photon pressure from sunlight. The new mission was dubbed K2. Because of the new pointing method, K2 is limited to looking at fields along the plane of our solar system, but this also offers new ways to use the telescope's sensitive detectors. From November 2014 to January 2015, Kepler's field included the planet Neptune. Amy Simon, a planetary scientist at NASA’s Goddard Space Flight Center, looked for the faint signal of moving clouds embedded within Neptune's light curve. The Kepler observations are unique, said Simon, because they allow us to see the light curve of an object close enough to image and resolve cloud features. These observations prove that rapid variations in light curves of brown dwarfs and exoplanets can be caused by changing clouds. Kepler is in an Earth-trailing heliocentric orbit, which just means that it's in orbit around the Sun and lagging behind the Earth, falling behind at the rate of 7.3 days per year. At the time of the Neptune observations, the spacecraft was trailing the Earth by about 6 weeks, or a little over 100 million kilometers. From this orbit, the K2 mission has identified hundreds of new exoplanet candidates.

    Learn more about Kepler's observation of Neptune.

  • The Planet Around Beta Pictoris Makes Waves
    A new NASA supercomputer simulation of the planet and debris disk around the nearby star Beta Pictoris reveals that the planet's motion drives spiral waves throughout the disk, a phenomenon that greatly increases collisions among the orbiting debris. Patterns in the collisions and the resulting dust appear to account for many observed features that previous research has been unable to fully explain. Astronomers Erika Nesvold (UMBC) and Marc Kuchner (NASA Goddard) essentially created a virtual Beta Pictoris in the computer and watched it evolve over millions of years. It is the first full 3-D model of a debris disk where scientists can watch the development of asymmetric features formed by planets, like warps and eccentric rings, and also track collisions among the particles at the same time.
  • Solar Wind Strips the Martian Atmosphere
    Today, Mars is a global desert with an atmosphere far too thin to support bodies of flowing water, but evidence shows that Mars was considerably wetter in the ancient past. Scientists think that climate change on Mars was caused by the loss of an early, thick atmosphere, and NASA’s MAVEN mission is investigating whether it was driven into space. One of the prime suspects is the solar wind, a stream of electrically charged particles continuously blowing outward from the Sun. Unlike Earth, Mars lacks a global magnetic field to deflect the incoming solar wind. Instead, charged particles from the Sun crash into the Mars upper atmosphere, and can accelerate Martian ions into space. Now, MAVEN has observed this process in action – by measuring the velocity of ions escaping from Mars. The movies on this page compare simulations of ion escape with MAVEN’s observations of oxygen ion flux. The results closely fit the expected pattern, with the most energetic ions (in red) accelerated in a plume above Mars, while the majority of escaping ions (green) are lost along the “tail” region in the wake of the solar wind. MAVEN’s observations confirm that the solar wind is a significant contributor to atmosphere loss on Mars, and they bring scientists closer to solving the mystery of the ancient Martian climate. Read the full press release about this finding.

    Watch the November 2015 MAVEN Science Update.

  • Disk Detective Tutorial
    Have you discovered a planetary system today? At DiskDetective.org, you can help NASA scientists find new planetary systems, by searching for disks of dust around nearby stars using images from the WISE space telescope and other telescopes. This tutorial, made by top citizen scientists based on their experience, will help you get started working together with professional astronomers on cutting-edge research, hunting through the Galaxy.
  • Debris Disks Generate Spirals, Rings and Arcs in Simulations
    When exoplanet scientists first spotted patterns in disks of dust and gas around young stars, they thought newly formed planets might be the cause. But a recent NASA study cautions that there may be another explanation one that doesn’t involve planets at all. An alternative explanation suggests the dust and gas in the disk can form the patterns themselves when they interact with starlight. When high-energy UV starlight hits dust grains, it strips away electrons. Those electrons collide with and heat nearby gas. As the gas warms, its pressure increases and it traps more dust, which in turn heats more gas. The resulting cycle, called the photoelectric instability (PeI), can work in tandem with other forces to create some of the features astronomers have previously associated with planets in debris disks. A 2013 study suggested PeI could explain the narrow rings seen in some disks. The model also predicted that some disks would have arcs, or incomplete rings, which weren’t directly observed in a disk until 2016. The new simulation includes an additional new factor: radiation pressure, a force caused by starlight striking dust grains. Light exerts a minute physical force on everything it encounters. This radiation pressure propels solar sails and helps direct comet tails so they always point away from the Sun. The same force can push dust into highly eccentric orbits, and even blow some of the smaller grains out of the disk entirely. The new research modeled how radiation pressure and PeI work together to affect the movement of dust and gas, and also found that the two forces manifest different patterns depending on the physical properties of the dust and gas.
  • Resonant Dust Ring Sculpted by a Super-Earth
    A planet twice the mass of Earth shepherds dust near its orbit into a circumstellar ring structure. Both the planet and the dust structure orbit the host star with a period of 5.2 years. Two regions of enhanced dust density lead and trail the planet, which causes periodic localized brightening.

    This simulation was computed using NASA GSFC's 420-processor Thunderhead cluster. Stark used the cluster to create a catalog of debris-disk structures caused by Earth-like planets.

    The catalog is available at http://asd.gsfc.nasa.gov/Christopher.Stark/catalog.php

Exoplanet Videos

Informational videos on exoplanets and the search for life in our solar system and beyond.
  • Alien Atmospheres
    Since the early 1990's, astronomers have known that extrasolar planets, or "exoplanets," orbit stars light-years beyond our own solar system. Although most exoplanets are too distant to be directly imaged, detailed studies have been made of their size, composition, and even atmospheric makeup - but how? By observing periodic variations in the parent star's brightness and color, astronomers can indirectly determine an exoplanet's distance from its star, its size, and its mass. But to truly understand an exoplanet astronomers must study its atmosphere, and they do so by splitting apart the parent star's light during a planetary transit.
  • Looking for the Shadows of New Worlds
    Astronomers have used many different methods to discover planets beyond the solar system, but the most successful by far is transit photometry, which measures changes in a star's brightness caused by a mini-eclipse. When a planet crosses in front of its star along our line of sight, it blocks some of the star's light. If the dimming lasts for a set amount of time and occurs at regular intervals, it likely means an exoplanet is passing in front of, or transiting, the star once every orbital period. NASA’s Kepler Space Telescope has used this technique to become the most successful planet-hunting spacecraft to date, with more than a thousand established discoveries and many more awaiting confirmation. Missions carrying improved technology are now planned, but how much more can they tell us about alien planetary systems similar to our own? A great deal, according to recently published studies by Michael Hippke at the Institute for Data Analysis in Neukirchen-Vluyn, Germany, and Daniel Angerhausen, a postdoctoral researcher at NASA's Goddard Space Flight Center in Greenbelt, Maryland. They show that in the best-case scenarios upcoming missions could uncover planetary moons, ringed worlds similar to Saturn, and even large collections of asteroids.
  • NASA's New Planet Hunter: TESS
    NASA’s Transiting Exoplanet Survey Satellite (TESS) will find undiscovered worlds around bright nearby stars, providing targets where future studies will assess their capacity to harbor life. TESS is a NASA Astrophysics Explorer mission led and operated by MIT and managed by Goddard. With the help of a gravitational assist from the Moon, the spacecraft will settle into a 13.7-day orbit around Earth. Four wide-field cameras will give TESS a field-of-view that covers 85 percent of the entire sky. Within this vast visual perspective, the sky has been divided into 26 sectors that TESS will observe one by one. The first year of observations will map the 13 sectors encompassing the southern sky, and the second year will map the 13 sectors of the northern sky. The spacecraft will be looking for a phenomenon known as a transit, where a planet passes in front of its star, causing a periodic and regular dip in the star’s brightness. NASA’s Kepler spacecraft used the same method to spot more than 2,600 confirmed exoplanets, most of them orbiting faint stars 300 to 3,000 light-years away TESS will concentrate on stars less than 300 light-years away and 30 to 100 times brighter than Kepler’s targets. The brightness of these target stars will allow researchers to use spectroscopy, the study of the absorption and emission of light, to determine a planet’s mass, density and atmospheric composition. Water and other key molecules in its atmosphere can give us hints about a planets’ capacity to harbor life.
  • TESS Shorts

    The Unique Orbit of NASA’s Newest Planet Hunter

    NASA's Transiting Exoplanet Survey Satellite - TESS will fly in an orbit that completes two circuits around the Earth every time the Moon orbits. This special orbit will allow TESS’s cameras to monitor each patch of sky continuously from nearly a month at a time. To get into this orbit, TESS will make a series of loops culminating in a lunar gravitational-assist, which will give it the push it needs. TESS will reach its orbit about 60 days after launch.

    Music: "Drive to Succeed" from Killer Tracks

    Complete transcript available.

    Watch this video on the NASA Goddard YouTube channel.

  • TESS Undergoes Integration and Testing
    The Transiting Exoplanet Survey Satellite (TESS) is the next step in the search for planets outside of our solar system, including those that could support life. The mission will find exoplanets that periodically block part of the light from their host stars, events called transits. TESS will survey 200,000 of the brightest stars near the sun to search for transiting exoplanets. The mission is scheduled to launch in 2018.
  • NASA's Planet-Hunting TESS Catches a Comet Before Starting Science
    Before NASA’s Transiting Exoplanet Survey Satellite (TESS) started science operations on July 25, 2018, the planet hunter sent back a stunning sequence of serendipitous images showing the motion of a comet. Taken over the course of 17 hours on July 25, these TESS images helped demonstrate the satellite’s ability to collect a prolonged set of stable periodic images covering a broad region of the sky — all critical factors in finding transiting planets orbiting nearby stars. Over the course of these tests, TESS took images of C/2018 N1, a comet discovered by NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) satellite on June 29. The comet, located about 29 million miles (48 million kilometers) from Earth in the southern constellation Piscis Austrinus, is seen to move across the frame from right to left as it orbits the Sun. The comet’s tail, which consists of gases carried away from the comet by an outflow from the Sun called the solar wind, extends to the top of the frame and gradually pivots as the comet glides across the field of view. In addition to the comet, the images reveal a treasure trove of other astronomical activity. The stars appear to shift between white and black as a result of image processing. The shift also highlights variable stars — which change brightness either as a result of pulsation, rapid rotation, or by eclipsing binary neighbors. Asteroids in our solar system appear as small white dots moving across the field of view. Towards the end of the video, one can see a faint broad arc of light moving across the middle section of the frame from left to right. This is stray light from Mars, which is located outside the frame. The images were taken when Mars was at its brightest near opposition, or its closest distance, to Earth. These images were taken during a short period near the end of the mission’s commissioning phase, prior to the start of science operations. The movie presents just a small fraction of TESS’s active field of view. The team continues to fine-tune the spacecraft’s performance as it searches for distant worlds. TESS is a NASA Astrophysics Explorer mission led and operated by MIT in Cambridge, Massachusetts, and managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Dr. George Ricker of MIT’s Kavli Institute for Astrophysics and Space Research serves as principal investigator for the mission. Additional partners include Northrop Grumman, based in Falls Church, Virginia; NASA’s Ames Research Center in California’s Silicon Valley; the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts; MIT’s Lincoln Laboratory in Lexington, Massachusetts; and the Space Telescope Science Institute in Baltimore. More than a dozen universities, research institutes and observatories worldwide are participants in the mission.
  • WFIRST: Uncovering the Mysteries of the Universe
    The Wide-Field Infrared Survey Telescope (WFIRST) is an upcoming space telescope designed to perform wide-field imaging and spectroscopy of the infrared sky. One of WFIRST’s objectives will be looking for clues about dark energy—the mysterious force that is accelerating the expansion of the universe. Another objective of the mission will be finding and studying exoplanets. WFIRST uses the same 2.4 meter telescope size as Hubble, but with 18 cutting-edge fourth-generation image sensors compared to Hubble's single first-generation sensor. As a result, each WFIRST image will cover over 200 times as much as a Hubble Wide Field Camera 3/IR image and be 300 megapixels in size. Hubble images reveal thousands of galaxies; a single WFIRST image will uncover millions. To help uncover the mystery of dark energy, WFIRST will make incredibly precise measurements of the universe. These measurements, like the distance and position of galaxies, can be compared to other measurements—such as the cosmic microwave background from the WMAP mission—to determine how dark energy has changed over time. WFIRST can also measure the slight distortions in light from distant galaxies as it passes more nearby mass concentrations. These data will build a three dimensional picture of how mass is distributed throughout the universe, and provide independent confirmation of its structure. Because WFIRST has such a large and sensitive field of view, it can find thousands of new exoplanets through a process called microlensing. When one star in the sky appears to pass nearly in front of another, the light rays of the background source star become bent due to the gravitational "attraction" of the foreground star. This "lens" star is then a virtual magnifying glass, amplifying the brightness of the background source star. If the lens star harbors a planetary system, then those planets can also act as lenses, each one producing a short deviation in the brightness of the source. For closer planets, WFIRST will open a new era of direct observation. Currently only a handful of planets are observable in light reflected off of them, and they are all large planets close to their stars. WFIRST will be able to detect planets as small as Neptune, and as far from their stars as Saturn is from the sun. This is possible thanks to newly developed coronagraphs, which block the bright light from the star to make the planet more visible.
  • WFIRST: The Best of Both Worlds
    NASA officially is beginning work on an astrophysics mission designed to help unlock the secrets of the universe -- the Wide Field Infrared Survey Telescope (WFIRST). With a view 100 times bigger than that of NASA’s Hubble Space Telescope, the Wide Field Infrared Survey Telescope WFIRST will aid researchers in their efforts to unravel the secrets of dark energy and dark matter, and explore the evolution of the cosmos. It also will discover new worlds outside our solar system and advance the search for worlds that could be suitable for life. WFIRST is the agency's next major astrophysics observatory, following the launch of the James Webb Space Telescope in 2018. The observatory will survey large regions of the sky in near-infrared light to answer fundamental questions about the structure and evolution of the universe, and expand our knowledge of planets beyond our solar system – known as exoplanets. It will carry a Wide Field Instrument for surveys, and a Coronagraph Instrument designed to block the glare of individual stars and reveal the faint light of planets orbiting around them. By blocking the light of the host star, the Coronagraph Instrument will enable detailed measurements of the chemical makeup of planetary atmospheres. Comparing these data across many worlds will allow scientists to better understand the origin and physics of these atmospheres, and search for chemical signs of environments suitable for life. The telescope’s sensitivity and wide view will enable a large-scale search for exoplanets by monitoring the brightness of millions of stars in the crowded central region of our galaxy. The survey will net thousands of new exoplanets similar in size and distance from their star as those in our own solar system, complementing the work started by NASA's Kepler mission and the upcoming work of the Transiting Exoplanet Survey Satellite. Employing multiple techniques, astronomers also will use WFIRST to track how dark energy and dark matter have affected the evolution of our universe. Dark energy is a mysterious, negative pressure that has been speeding up the expansion of the universe. Dark matter is invisible material that makes up most of the matter in our universe. By measuring the distances of thousands of supernovae, astronomers can map in detail how cosmic expansion has increased with time. WFIRST also can precisely measure the shapes, positions and distances of millions of galaxies to track the distribution and growth of cosmic structures, including galaxy clusters and the dark matter accompanying them. WFIRST is slated to launch in the mid-2020s. The observatory will begin operations after traveling to a gravitational balance point known as Earth-Sun L2, which is located about one million miles from Earth in a direction directly opposite the Sun. WFIRST is managed at Goddard, with participation by the Jet Propulsion Laboratory (JPL) in Pasadena, California, the Space Telescope Science Institute in Baltimore, the Infrared Processing and Analysis Center, also in Pasadena, and a science team comprised of members from U.S. research institutions across the country.
  • WFIRST Will See the Big Picture of the Universe
    Scheduled to launch in the mid-2020s, the Wide Field Infrared Survey Telescope (WFIRST) will function as Hubble’s wide-eyed cousin. While just as sensitive as Hubble's cameras, WFIRST's 300-megapixel Wide Field Instrument will image a sky area 100 times larger. This means a single WFIRST image will hold the equivalent detail of 100 pictures from Hubble. The mission’s wide field of view will allow it to generate a never-before-seen big picture of the universe, which will help astronomers explore some of the greatest mysteries of the cosmos, like why the expansion of the universe seems to be accelerating. Some scientists attribute the speed-up to dark energy, an unexplained pressure that makes up 68 percent of the total content of the cosmos. The Wide Field Instrument will also allow WFIRST to measure the matter in hundreds of millions of distant galaxies through a phenomenon dictated by Einstein’s relativity theory. Massive objects like galaxies curve space-time in a way that bends light passing near them, creating a distorted, magnified view of far-off galaxies behind them. WFIRST will paint a broad picture of how matter is structured throughout the universe, allowing scientists to put the governing physics of its assembly to the ultimate test. WFIRST can use this same light-bending phenomenon to study planets beyond our solar system, known as exoplanets. In a process called microlensing, a foreground star in our galaxy acts as the lens. When its motion randomly aligns with a distant background star, the lens magnifies, brightens and distorts the background star. WFIRST's microlensing survey will monitor 100 million stars for hundreds of days and is expected to find about 2,500 planets, well targeted at rocky planets in and beyond the region where liquid water may exist. These results will make WFIRST an ideal companion to missions like NASA's Kepler and the upcoming Transiting Exoplanet Survey Satellite (TESS), which are designed to study larger planets orbiting closer to their host stars. Together, discoveries from these three missions will help complete the census of planets beyond our solar system. The combined data will also overlap in a critical area known as the habitable zone, the orbiting distance from a host star that would permit a planet's surface to harbor liquid water — and potentially life. By pioneering an array of innovative technologies, WFIRST will serve as a multipurpose mission, formulating a big picture of the universe and helping us answer some of the most profound questions in astrophysics, such as how the universe evolved into what we see today, its ultimate fate and whether we are alone.
  • Hubble Observes Atmospheres of TRAPPIST-1 Exoplanets in the Habitable Zone
    Astronomers using the Hubble Space Telescope have conducted the first spectroscopic survey of Earth-sized planets in the TRAPPIST-1 system's habitable zone. Hubble reveals that at least the inner five planets do not seem to contain puffy, hydrogen-rich atmospheres similar to gaseous planets such as Neptune. This means the atmospheres may be more shallow and rich in heavier gases like carbon dioxide, methane, and oxygen. Find the full story and press release at hubblesite.org. Read the joint Hubble and Spitzer findings on nasa.gov. The science paper is available from Nature Astronomy.
  • Europa Water Vapor Plumes - More Hubble Evidence
    The Hubble Space Telescope has captured even more evidence of water vapor plumes on Jupiter's icy moon Europa. The probable plumes appear to be repeating in the same location and correspond with a relatively warm region on Europa's surface observed by the Galileo spacecraft. Read the press release here - https://www.nasa.gov/press-release/nasa-missions-provide-new-insights-into-ocean-worlds-in-our-solar-system View the release images on the HubbleSite here - http://hubblesite.org/news_release/news/2017-17 Read the science paper here - http://iopscience.iop.org/article/10.3847/2041-8213/aa67f8/pdf
  • Hubble Directly Images Possible Plumes on Europa
    NASA's Hubble Space Telescope took direct ultraviolet images of the icy moon Europa transiting across the disk of Jupiter. Out of ten observations, Hubble saw what may be water vapor plumes on three of the images. This adds another piece of supporting evidence to the existence of water vapor plumes on Europa - Hubble also detected spectroscopic signatures of water vapor in 2012. The existence of water vapor plumes could provide NASA's Europa flyby mission the opportunity to study the conditions and habitability of Europa's subsurface ocean. Read the full nasa.gov story here: http://www.nasa.gov/press-release/nasa-s-hubble-spots-possible-water-plumes-erupting-on-jupiters-moon-europa Read the full science paper here: http://hubblesite.org/pubinfo/pdf/2016/33/pdf.pdf Full details on the images can be found on HubbleSite.org: http://hubblesite.org/newscenter/archive/releases/2016/33/ Additional Resources: JPL's "Europa: Tempting Target for Future Exploration" video file is downloadable here: https://vimeo.com/118505538 Read the Dec 2013 press release about Hubble's previous observations of Europa here: http://www.nasa.gov/content/goddard/hubble-europa-water-vapor
  • Hubble, Swift Detect First-ever Changes in an Exoplanet Atmosphere
    An international team of astronomers using data from NASA's Hubble Space Telescope has detected significant changes in the atmosphere of a planet located beyond our solar system. The scientists conclude the atmospheric variations occurred in response to a powerful eruption on the planet's host star, an event observed by NASA's Swift satellite.

    The exoplanet is HD 189733b, a gas giant similar to Jupiter, but about 14 percent larger and more massive. The planet circles its star at a distance of only 3 million miles, or about 30 times closer than Earth's distance from the sun, and completes an orbit every 2.2 days. Its star, named HD 189733A, is about 80 percent the size and mass of our sun.

    Astronomers classify the planet as a "hot Jupiter." Previous Hubble observations show that the planet's deep atmosphere reaches a temperature of about 1,900 degrees Fahrenheit (1,030 C).

    HD 189733b periodically passes across, or transits, its parent star, and these events give astronomers an opportunity to probe its atmosphere and environment. In a previous study, a group led by Lecavelier des Etangs used Hubble to show that hydrogen gas was escaping from the planet's upper atmosphere. The finding made HD 189733b only the second-known "evaporating" exoplanet at the time.

    The system is just 63 light-years away, so close that its star can be seen with binoculars near the famous Dumbbell Nebula. This makes HD 189733b an ideal target for studying the processes that drive atmospheric escape.

    When HD 189733b transits its star, some of the star's light passes through the planet's atmosphere. This interaction imprints information on the composition and motion of the planet's atmosphere into the star's light.

    In April 2010, the researchers observed a single transit using Hubble's Space Telescope Imaging Spectrograph (STIS), but they detected no trace of the planet's atmosphere. Follow-up STIS observations in September 2011 showed a surprising reversal, with striking evidence that a plume of gas was streaming away from the exoplanet.

    The researchers determined that at least 1,000 tons of gas was leaving the planet's atmosphere every second. The hydrogen atoms were racing away at speeds greater than 300,000 mph.

    Because X-rays and extreme ultraviolet starlight heat the planet's atmosphere and likely drive its escape, the team also monitored the star with Swift's X-ray Telescope (XRT). On Sept. 7, 2011, just eight hours before Hubble was scheduled to observe the transit, Swift was monitoring the star when it unleashed a powerful flare. It brightened by 3.6 times in X-rays, a spike occurring atop emission levels that already were greater than the sun's. Astronomers estimate that HD 189733b encountered about 3 million times as many X-rays as Earth receives from a solar flare at the threshold of the X class.

  • Planetary Studies Web Feature
    The Webb Space Telescope will study planetary bodies with our solar system and planets orbiting other stars to help scientists better understand how planets form and how they evolve.
  • JWST Feature - Planetary Evolution
    A fully produced video about planetary evolution and how the Webb Telelscope's ability to see inside dense clouds of gas and dust will help us better understand solar system formation and evolution.
  • Hubble Makes First Measurements of Earth-Sized Exoplanet Atmospheres
    On May 4th, 2016, the Hubble Space Telescope made the first spectroscopic measurements of two of the three known Earth-sized exoplanets in the TRAPPIST-1 system just 40 light-years away. Now the results are in: a thick, puffy, hydrogen-helium atmosphere is likely ruled out from the possible range of atmospheres for these two planets. Additional visuals from the European Southern Observatory can be downloaded here: http://www.eso.org/public/news/eso1615/E
  • 'Winking' Star May Be Devouring Wrecked Planets
    Astronomers studying the star RZ Piscium have found evidence suggesting its strange, unpredictable dimming episodes may be caused by vast orbiting clouds of gas and dust, the remains of one or more destroyed planets. Young stars are often prodigious X-ray sources. Observations using the European Space Agency's XMM-Newton satellite, show that RZ Piscium is, too. Its total X-ray output is roughly 1,000 times greater than our Sun's. Ground-based observations show the star's surface temperature to be about 9,600 degrees Fahrenheit (5,330 degrees Celsius), only slightly cooler than the Sun's. They also show RZ Piscium is enriched in the tell-tale element lithium, which is slowly destroyed by nuclear reactions inside stars and serves as a clock indicating the elapsed time since a star's birth. Ground-based telescopes also reveal large amounts of dust and hydrogen-rich gas in the system, suggesting that large blobs of this material are orbiting the star and causing the brightness dips. The best explanation that accounts for all of the available data, say the researchers, is that the star is encircled by debris representing the aftermath of a disaster of planetary proportions. It's possible the star's tides may be stripping material from a close substellar companion or giant planet, producing intermittent streams of gas and dust, or that the companion is already completely dissolved. Another possibility is that one or more massive gas-rich planets in the system underwent a catastrophic collision in the astronomically recent past.
  • Microlensing Study: Most Common Outer Planets Likely Neptune-mass
    A new statistical study of planets found by a technique called gravitational microlensing suggests that Neptune-mass worlds are likely the most common type of planet to form in the icy outer realms of planetary systems. The study provides the first indication of the types of planets waiting to be found far from a host star, where scientists suspect planets form most efficiently. Contrary to some theoretical predictions, the most numerous cold exoplanets have masses similar to Neptune, and there doesn't seem to be the expected increase in number at lower masses. Lead scientist Daisuke Suzuki, a post-doctoral researcher at NASA's Goddard Space Flight Center in Greenbelt, Maryland, infer this from current detections. The team concludes that Neptune-mass planets in outer orbits are about 10 times more common than Jupiter-mass planets in Jupiter-like orbits. Gravitational microlensing takes advantage of the light-bending effects of massive objects predicted by Einstein's general theory of relativity. It occurs when a foreground star, the lens, randomly aligns with a distant background star, the source, as seen from Earth. As the lensing star drifts along in its orbit around the galaxy, the alignment shifts over days to weeks, changing the apparent brightness of the source. The precise pattern of these changes provides astronomers with clues about the nature of the lensing star, including any planets it may host. Typically, the technique provides the mass ratio of the planet to the host star and their separation. Microlensing holds great potential. It can detect planets hundreds of times more distant than most other methods, allowing astronomers to investigate a broad swath of our Milky Way galaxy. The technique can locate exoplanets at smaller masses and greater distances from their host stars, and it's sensitive enough to find planets floating through the galaxy on their own, unbound to stars. Microlensing surveys complement other methods best suited to find planets closer to their stars. From 2007 to 2012, the Microlensing Observations in Astrophysics (MOA) group, a collaboration between researchers in Japan and New Zealand, issued 3,300 alerts informing the astronomical community about ongoing microlensing events. Suzuki's team identified 1,474 well-observed microlensing events, with 22 displaying clear planetary signals. This includes four planets that were never previously reported. To study these events in greater detail, the team included data from the other major microlensing project operating over the same period, the Optical Gravitational Lensing Experiment (OGLE), as well as additional observations from other projects designed to follow up on MOA and OGLE alerts. From this information, the researchers determined the frequency of planets compared to the mass ratio of the planet and star as well as the distances between them. For a typical planet-hosting star with about 60 percent the sun's mass, the typical microlensing planet is a world between 10 and 40 times Earth's mass. For comparison, Neptune in our own solar system has the equivalent mass of 17 Earths. The results imply that cold Neptune-mass worlds are the most common types of planets beyond the so-called snow line, the point where water remained frozen during planetary formation. In the solar system, the snow line is thought to have been located at about 2.7 times Earth's mean distance from the sun, placing it in the middle of the main asteroid belt today. NASA's Wide Field Infrared Survey Telescope (WFIRST), slated to launch in the mid-2020s, will conduct an extensive microlensing survey. Astronomers expect it will deliver mass and distance determinations of thousands of planets, completing the work begun by NASA's Kepler mission and providing the first galactic census of planetary properties.
  • Disk Detective: Search for Planetary Habitats
    A new NASA-sponsored website, DiskDetective.org, lets the public discover embryonic planetary systems hidden among data from NASA's Wide-field Infrared Survey Explorer (WISE) mission.

    The site is led and funded by NASA and developed by the Zooniverse, a collaboration of scientists, software developers and educators who collectively develop and manage the Internet's largest, most popular and most successful citizen science projects.

    WISE, located in Earth orbit and designed to survey the entire sky in infrared light, completed two scans between 2010 and 2011. It took detailed measurements of more than 745 million objects, representing the most comprehensive survey of the sky at mid-infrared wavelengths currently available. Astronomers have used computers to search this haystack of data for planet-forming environments and narrowed the field to about a half-million sources that shine brightly in the infrared, indicating they may be "needles": dust-rich circumstellar disks that are absorbing their star's light and reradiating it as heat.

    Planets form and grow within these disks. But galaxies, interstellar dust clouds, and asteroids also glow in the infrared, which stymies automated efforts to identify planetary habitats.

    Disk Detective incorporates images from WISE and other sky surveys in the form of brief animations the website calls flip books. Volunteers view a flip book and then classify the object based on simple criteria, such as whether the image is round or includes multiple objects. By collecting this information, astronomers will be able to assess which sources should be explored in greater detail.

    The project aims to find two types of developing planetary environments. The first, known as young stellar object disks, typically are less than 5 million years old, contain large quantities of gas, and are often found in or near young star clusters. For comparison, our own solar system is 4.6 billion years old.

    The other type of habitat is called a debris disk. These systems tend to be older than 5 million years, possess little or no gas, and contain belts of rocky or icy debris that resemble the asteroid and Kuiper belts found in our own solar system. Vega and Fomalhaut, two of the brightest stars in the sky, host debris disks.

    Through Disk Detective, volunteers will help the astronomical community discover new planetary nurseries that will become future targets for NASA's Hubble Space Telescope and its successor, the James Webb Space Telescope.

  • Beta Pictoris: Icy Debris Suggests 'Shepherd' Planet
    An international team of astronomers exploring the disk of gas and dust the bright star Beta Pictoris have uncovered a compact cloud of poisonous gas formed by ongoing rapid-fire collisions among a swarm of icy, comet-like bodies. The researchers suggest the comet swarm may be frozen debris trapped and concentrated by the gravity of an as-yet-unseen planet.

    Using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, astronomers mapped millimeter-wavelength light from dust and carbon monoxide (CO) molecules in a disk surrounding the star. Located about 63 light-years away and only 20 million years old, Beta Pictoris hosts one of the closest, brightest and youngest debris disks known, making it an ideal laboratory for studying the early development of planetary systems.

    The ALMA images reveal a vast belt of carbon monoxide located at the fringes of the system. Much of the gas is concentrated in a single clump located about 8 billion miles (13 billion kilometers) from the star, or nearly three times the distance between the planet Neptune and the sun. The total amount of CO observed, the scientists say, exceeds 200 million billion tons, equivalent to about one-sixth the mass of Earth’s oceans.

    The presence of all this gas is a clue that something interesting is going on because ultraviolet starlight breaks up CO molecules in about 100 years, much faster than the main cloud can complete a single orbit around the star. Scientists calculate that a large comet must be completely destroyed every five minutes to offset the destruction of CO molecules. Only an unusually massive and compact swarm of comets could support such an astonishingly high collision rate.

    The researchers think these comet swarms formed when a as-yet-undetected planet migrated outward, sweeping icy bodies into resonant orbits. When the orbital periods of the comets matched the planet's in some simple ratio – say, two orbits for every three of the planet – the comets received a nudge from the planet at the same location each orbit. Like the regular push of a child's swing, these accelerations amplify over time and work to confine the comets in a small region.

  • 'Disk Detectives' Top 1 Million Classifications in Search for Planetary Habitats
    Citizen scientists using the NASA-sponsored website DiskDetective.org have logged 1 million classifications of potential debris disks and disks surrounding young stellar objects (YSO). This data will help provide a crucial set of targets for future planet-hunting missions. By combing through objects identified in an infrared survey made with NASA's Wide-field Infrared Survey Explorer (WISE) mission, Disk Detective aims to find two types of developing planetary environments: YSO disks, which are less than 5 million years old and contains large quantities of gas, and debris disks, which tend to be older than 5 million years, and contain belts of rocky or icy debris. Computer searches already have identified some objects seen by the WISE survey as potential dust-rich disks. But software can't distinguish them from other infrared-bright sources, such as galaxies, interstellar dust clouds and asteroids. There may be thousands of potential planetary systems in the WISE data, but the only way to know for sure is to inspect each source by eye. At DiskDetective.org, volunteers watch a 10-second "flip book" of a disk candidate shown at several different wavelengths as observed from three different telescopes, including WISE. They then click one or more buttons that best describe the object's appearance. Each classification helps astronomers decide which images may be contaminated by background galaxies, interstellar matter or image artifacts, and which may be real disks that should be studied in more detail. Some 28,000 visitors around the world have participated in the project to date. The project has so far netted 478 objects of interest, which the team is investigating with a variety of ground-based telescopes in Arizona, California, New Mexico, Argentina and Chile. Disk Detective currently includes about 278,000 WISE sources. The team expects to wrap up the current project sometime in 2018, with a total of about 3 million classifications and perhaps 1,000 disk candidates. The researchers then plan to add an additional 140,000 targets to the site.
  • How to Find a Living Planet
    The more we see other planets, the more the question comes into focus: Maybe we're the weird one? Decades of observing Earth from space has informed our search for signs of habitability and life on exoplanets and even planets in our own solar system. We're taking a closer look at what we've learned about Earth - our only example of a planet with life - to search for life in the universe.
  • Using Color to Search for Alien Earths
    NASA astronomer Lucy McFadden and UCLA graduate Carolyn Crow recently made a discovery that will help identify characteristics of extrasolar planets, such as the compositions of their surfaces and atmospheres. By comparing the reflected red, blue, and green light from planets in our solar system, a team led by Crow and McFadden was able to group the planets according to their similarities. As it turns out, the planets fall into very distinct regions on this plot, where the vertical direction indicates the relative amount of blue light, and the horizontal direction the relative amount of red light.

    This technique works even when the source of the reflected light is visible only as a point, like exoplanets appear when observed through a telescope. Therefore, scientists can use it to identify earthlike planets more easily.

  • MAVEN Reveals Mars Argon Loss to Space
    Solar wind and radiation are responsible for stripping the Martian atmosphere, according to results from NASA's MAVEN mission. By measuring light and heavy isotopes of argon in the Martian atmosphere, scientists have determined that the majority of the planet's air and water were removed to space by sputtering. In this process, ions from the Mars atmosphere get picked up by the solar wind and slammed into other atoms at the top of the atmosphere, knocking them into space.

    Scientists used measurements of light and heavy argon from MAVEN and NASA's Curiosity rover to determine that sputtering has removed 65% of Mars' argon to space, along with the majority of other gases like carbon dioxide. Over billions of years, this transformed Mars from a hospitable environment into the cold, dry planet that we see today.
    Learn more about the MAVEN argon loss finding.
  • Ultraviolet Mars Reveals Cloud Formation
    Images from MAVEN's Imaging UltraViolet Spectrograph were used to make this movie of rapid cloud formation on Mars on July 9-10, 2016. The ultraviolet colors of the planet have been rendered in false color, to show what we would see with ultraviolet-sensitive eyes. The movie uses four MAVEN images to show about 7 hours of Mars rotation during this period, and interleaves simulated views that would be seen between the four images. Mars' day is similar to Earth’s, so the movie shows just over a quarter day. The left part of the planet is in morning and the right side in afternoon. Mars’ prominent volcanoes, topped with white clouds, can be seen moving across the disk. Mars’ tallest volcano, Olympus Mons, appears as a prominent dark region near the top of the images, with a small white cloud at the summit that grows during the day. Olympus Mons appears dark because the volcano rises up above much of the hazy atmosphere which makes the rest of the planet appear lighter. Three more volcanoes appear in a diagonal row, with their cloud cover merging to span up to a thousand miles by the end of the day. These images are particularly interesting because they show how rapidly and extensively the clouds topping the volcanoes form in the afternoon. Similar processes occur at Earth, with the flow of winds over mountains creating clouds. Afternoon cloud formation is a common occurrence in the American West, especially during the summer.
  • Investigating the Martian Atmosphere
    The Martian surface bears ample evidence of flowing water in its youth, from crater lakes and riverbeds to minerals that only form in water. But today Mars is cold and dry, and scientists think that the loss of Mars' water may have been caused by the loss of its early atmosphere. NASA's Mars Atmosphere and Volatile EvolutioN mission, or MAVEN, will be the first spacecraft devoted to studying the Red Planet's upper atmosphere, in an effort to understand how the Martian climate has changed over time.
  • MAVEN: Mars Atmospheric Loss
    When you take a look at Mars, you probably wouldn't think that it looks like a nice place to live. It's dry, it's dusty, and there's practically no atmosphere. But some scientists think that Mars may have once looked like a much nicer place to live, with a thicker atmosphere, cloudy skies, and possibly even liquid water flowing over the surface. So how did Mars transform from a warm, wet world to a cold, barren desert? NASA's MAVEN spacecraft will give us a clearer idea of how Mars lost its atmosphere (and thus its water), and scientists think that several processes have had an impact.

    Learn more about these processes in the videos below!

Interviews with Researchers

Scientists discuss the latest advances in exoplanet research.
  • Mercury Transit Live Shots May 9, 2016

    NASA will broadcast a stunning view of Mercury on May 9 as it journeys across the sun. The event, known as a transit, occurs when Mercury passes directly between Earth and the sun. This rare phenomenon will cause Mercury to look like a black dot gliding across the sun’s face. Mercury’s last transit was in 2006, and it won’t happen again until 2019!

    Starting at 7:12 a.m. EDT, Mercury will spend more than seven hours travelling across the sun. NASA’s Solar Dynamics Observatory will take the first near real time, ultra-high definition images ever for this event. This is also an opportunity for NASA scientists to fine tune the spacecraft’s cameras, using a method that can only be done during a transit.

    NASA scientists are available Monday, May 9 from 6:00 a.m. – 11:30 a.m. EDT to show your viewers amazing images of this event as it unfolds. Scientists will also share why transits are important, and how they’re being used to learn more about planets in our solar system—and beyond.

    Scientists have been using transits for hundreds of years to study the planets in our solar system. When a planet crosses in front of the sun, it causes the sun’s brightness to dim. Scientists can measure similar brightness dips from other stars to find planets orbiting them, and can calculate their sizes, how far away the planets are from their stars, and even get hints of what they’re made of. Upcoming NASA missions will watch for transits outside our solar system in order to find new planets, including some that could resemble Earth.

    ****To book a window*** Contact Claire Saravia – claire.g.desaravia@nasa.gov Suggested questions:

    1. Mercury is trekking across the sun today for the first time in 10 years. How can we see this transit? 2. Why are transits so important to astronomers? 3. Why does NASA watch the sun? 4. NASA is using the transit method to study planets beyond our solar system. What do we expect to learn from future missions doing this? 5. Where can we learn more?

    HD Satellite Coordinates for AMC9-K17: AMC-9 Ku-band Xp 17 Slot AB| 83.0 ° W Longitude | DL 12045.8 MHz | Horizontal Polarity | QPSK/DVB-S | FEC 3/4 | SR 13.235 Mbps | DR 18.2954 MHz | HD 720p | Format MPEG2 | Chroma Level 4:2:0 | Audio Embedded

    Mercury Transit Gallery Page

  • 2017 Spring Equinox Live Shots
    March 20 Equinox Marks the Start of Spring in the Northern Hemisphere

    Dance of the Solar System is the First Solar Event of 2017

    Stay Tuned for the Big Event of 2017, the August Solar Eclipse!

    It may not feel like it this week in parts of the country, but spring begins in just a few days. March 20 kicks off the first day of astronomical spring in the Northern Hemisphere. On March 20, the day of the spring Equinox, the sun will pass directly over the Earth’s equator, giving the entire planet equal hours of day and night. This is the seasonal marker in Earth’s orbit around the sun when daylight hours begin to get longer than night.

    This dance of the solar system is just one celestial event we’ll see this year. On August 21 all 50 states in the U.S. will be in prime position to see a partial or even a total solar eclipse, which happens when the moon is in perfect position to blot out the sun’s bright disk. The last time the U.S. saw a coast-to-coast solar eclipse was in 1918! The path of totality runs from Oregon to South Carolina.

    NASA will lead an unprecedented science initiative during the eclipse that will draw on the collaboration of the public to help collect images, data and even temperature readings from across the nation during the hour-and-a-half it takes to cross the continent.

    NASA scientists are available on Monday, March 20 from 6:00 a.m. – 11:30 a.m. EDT to help your viewers ring in the new season and talk about the big solar event this August.

    ***To book a window contact*** Michelle Handleman / michelle.z.handleman@nasa.gov/ 301-286-0918

    HD Satellite Coordinates for G17-K18Upper: Galaxy 17 Ku-band Xp 18 Slot Upper| 91.0 ° W Longitude | DL 12069.0 MHz | Vertical Polarity | QPSK/DVB-S | FEC 3/4 | SR 13.235 Mbps | DR 18.2954 MHz | HD 720p | Format MPEG2 | Chroma Level 4:2:0 | Audio Embedded

    Suggested Questions:

    1. What is an equinox?

    2. There is an exciting event happening this year: a total solar eclipse! When is this happening?

    3. NASA will be doing some pretty cool science during the eclipse. How is NASA using the eclipse to study the sun and Earth?

    4. How do eclipses help us find planets orbiting other stars?

    5. Where can we learn more?

    Live Shot Details:

    Location: NASA’s Goddard Space Flight Center/Greenbelt, Maryland


    Dr. Alex Young/ NASA Scientist

    Dr. Yari Collado-Vega / NASA Scientist [Interviews in Spanish]

    Dr. Nicholeen Viall / NASA Scientist

    Video: NASA will roll all insert videos during live interviews. If needed, stations can roll a clean feed of all video at 5:45 a.m. EDT on March 20, at the above listed satellite.

  • Exoplanet Live Shots 2.23.17
    NASA's Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water. You can find graphics HERE that go with this story. The discovery sets a new record for greatest number of habitable-zone planets found around a single star outside our solar system. All of these seven planets could have liquid water–key to life as we know it–under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.

    Scientists are available for live TV or radio interviews on Thursday, Feb. 23, from 6:00 a.m. – 11:30 a.m. EST to share these exciting results with your morning viewers, and talk about how NASA is exploring these strange new worlds. We will also give you a sneak peek into upcoming NASA missions that will further the search for life in the universe.

    HD Satellite Coordinates for G17-K18Upper: Galaxy 17 Ku-band Xp 18 Slot Upper| 91.0 ° W Longitude | DL 12069.0 MHz | Vertical Polarity | QPSK/DVB-S | FEC 3/4 | SR 13.235 Mbps | DR 18.2954 MHz | HD 720p | Format MPEG2 | Chroma Level 4:2:0 | Audio Embedded

    **** To book a window contact **** Michelle Handleman/ michelle.z.handleman@nasa.gov/ 301-286-0918

    Live Shot Details:

    Location: NASA’s Goddard Space Flight Center/Greenbelt, Maryland


    Dr. Paul Hertz / Director, Astrophysics Science Division, NASA Headquarters Washington

    Dr. Padi Boyd / Chief , Exoplanets and Stellar Astrophysics Laboratory

    Dr. Nikole Lewis / Astronomer, Space Telescope Science Institute

    Dr. Hannah Wakeford / NASA Scientist

  • NASA Preparing to Launch New Planet-Hunting Mission Live Shots
    NASA Preparing to Launch New Planet Hunting Mission Next Week
    Mission Expected to Discover Thousands of New Worlds Orbiting Nearby Stars
    NASA Scientists Available to Speak On the Hunt For New Worlds
    The hunt is on to discover new and exciting worlds! NASA’s Transiting Exoplanet Survey Satellite – TESS – is scheduled to launch April 16 to find thousands of planets orbiting stars outside our solar system, known as exoplanets. In the past ten years, NASA has discovered and studied thousands of these planets – including the TRAPPIST-1 system, which could have the ingredients to support life. TESS is expected to add thousands more planets to this growing list during its two-year mission, looking at the nearest and brightest stars in our galaxy to see if there are worlds hiding in their light.

    From molten lava and frigid icy planets, to bizarre places that rain rubies and sapphires and water-covered worlds, the possibilities of new worlds for the planet-hunter to find are limitless. Are Earth and the other planets in our solar system unique? Join NASA scientists from 6:00 a.m. to 12:00 p.m. EDT on Tuesday, April 10 – days before the launch – as they share some of the exciting discoveries they hope to find with the TESS mission.

    TESS will find promising planets that other NASA telescopes – like the Hubble Space Telescope and future James Webb Space Telescope – could look at in more detail to determine what their atmospheres are made of, and whether these unknown worlds could potentially support life. Suggested Questions:
    1. What is an exoplanet and why are scientists excited about them?
    2. How will this new mission help NASA in the search for life?
    3. Will this planet-hunter change the way we look at the stars in the night sky?
    4. Previous telescopes have found really unusual worlds. What kinds of planets are you looking forward to TESS discovering?
    5. Where can we learn more?
    Questions for longer interviews:
    1. Where will TESS orbit?
    2. What has been the biggest surprise in searching for exoplanets?
    3. How will TESS detect planets?
    4. What makes TESS different than other planet hunter missions?
    5. What does it look like when a planet crosses in front of the parent star?
    Live Shot Details: Location: NASA’s Goddard Space Flight Center/Greenbelt, Maryland

    Dr. Paul Hertz / NASA Director of Astrophysics
    Dr. Joshua Schlieder / NASA Scientist
    Dr. Jennifer Burt / MIT Torres postdoctoral fellow
    Natalia Guerrero / MIT Kavli TESS Objects of Interest Deputy Manager [ en Español ]z

  • MAVEN Results Live Shot Page
    On Thursday, November 5, 2015, NASA's Mars Atmosphere and Volatile Evolution Mission (MAVEN) has released its first results showing how Mars is losing its atmosphere to space. These results will help scientists understand why Mars' climate has changed, and why the planet has evolved from being warm and wet to cold and dry. Scientists were available Friday, November 6 to discuss these results, and what we can learn from them.

Exoplanet Missions

Learn more about the different NASA missions to study exoplanets.
  • Transiting Exoplanet Survey Satellite (TESS)
    The Transiting Exoplanet Survey Satellite (TESS) is a NASA Explorer mission launching in 2018 to study exoplanets, or planets orbiting stars outside our solar system. TESS will discover thousands of exoplanets in orbit around the brightest stars in the sky. It will monitor more than 200,000 stars, looking for temporary dips in brightness caused by planets transiting across these stars. This first-ever spaceborne all-sky transit survey will identify a wide range of planets, from Earth-sized to gas giants. The mission will find exoplanet candidates for follow-up observation from missions like the James Webb Space Telescope, which will determine whether these candidates could support life.

    For more information, please visit the TESS website.

  • Hubble Space Telescope
    The Hubble Space Telescope has been providing world-renowned science observations since 1990. Hubble is run by the NASA Goddard Space Flight Center, the Space Telescope Science Institute, and the European Space Agency (ESA).

    NASA's Hubble website - nasa.gov/hubble
    Space Telescope Science Institute's Hubble website - hubblesite.org
    ESA's Hubble website - spacetelescope.org


    The Wide Field Infrared Survey Telescope

    WFIRST is a NASA observatory designed to perform Wide Field imaging and surveys of the near infrared (NIR) sky. The current design of the mission makes use of an existing 2.4m telescope, which is the same size as the Hubble Space Telescope. WFIRST is the top-ranked large space mission in the New Worlds, New Horizon Decadal Survey of Astronomy and Astrophysics. The Wide Field Instrument will provide a field of view of the sky that is 100 times larger than images provided by HST. The coronagraph will enable astronomers to detect and measure properties of planets in other solar systems.

    More information about WFIRST

  • James Webb Space Telescope
    The James Webb Space Telescope (sometimes called JWST) is a large, infrared-optimized space telescope. The project is working to a 2021 launch date. Webb will find the first galaxies that formed in the early Universe, connecting the Big Bang to our own MIlky Way Glaxy. Webb will peer through dusty clouds to see stars forming planetary systems, connecting the Milky Way to our own Solar System. Webb's instruments are designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range. Webb will have a large primary mirror, 6.5 meters (21.3 feet) in diameter and a sunshield the size of a tennis court. Both the mirror and sunshade won't fit onto the Ariane 5 rocket fully open, so both will fold up and open once Webb is in outer space. Webb will operate in an orbit about 1.5 million km (1 million miles) from the Earth. The James Webb Space Telescope was named after the NASA Administrator who crafted Apollo program, and who was a staunch supporter of space science.

Exoplanet Presentations

Presentations given by scientists describing the latest developments in exoplanet research.
  • 2017 AGU Habitability Press Conference
    Spanning Disciplines to Search for Life Beyond Earth The search for life beyond Earth is riding a surge of creativity and innovation. Following a gold rush of exoplanet discovery over the past two decades, it is time to tackle the next step: determining which of the known exoplanets are proper candidates for life.

    Scientists from NASA and two universities presented new results dedicated to this task in fields spanning astrophysics, Earth science, heliophysics and planetary science — demonstrating how a cross-disciplinary approach is essential to finding life on other worlds — at the fall meeting of the American Geophysical Union on Dec. 13, 2017, in New Orleans, Louisiana. PANELISTS: • Giada Arney, NASA’s Goddard Space Flight Center • Stephen Kane, University of California-Riverside • Katherine Garcia-Sage, NASA’s Goddard Space Flight Center/Catholic University of America • Dave Brain, University of Colorado-Boulder

  • WFIRST 2017 AAS Hyperwall Presentation
    New hyperwall resources for Neil Gehrels' 2017 AAS talk. Most visuals are 5760x3240 and designed for a 3x3 hyperwall with 1920x1080 screens.
  • NASM 2016: The Search For Life
    On September 21, 2016, NASA scientists and stakeholders came together at the Smithsonian National Air and Space Museum for a presentation on the agency’s search for life beyond Earth. “The Search for Life” featured presentations from some of NASA’s leading scientists, including the late former astronaut, Dr. Piers Sellers. Through compelling visualizations, “The Search for Life” takes you on a journey through the solar system and beyond, exploring the possibility of life existing on Mars, the solar system’s outer moons, and exoplanets.

Hyperwall Materials

Exoplanet-related resources that can be used for presentations on the hyperwall or other high-resolution formats.
  • TRAPPIST-1 Exoplanet Lineup
    This artist's concept shows what the TRAPPIST-1 planetary system may look like, based on available data about the planets’ diameters, masses and distances from the host star. The system has been revealed through observations from NASA's Spitzer Space Telescope and the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope, as well as other ground-based observatories. The system was named for the TRAPPIST telescope. The seven planets of TRAPPIST-1 are all Earth-sized and terrestrial, according to research published in 2017 in the journal Nature. TRAPPIST-1 is an ultra-cool dwarf star in the constellation Aquarius, and its planets orbit very close to it. They are likely all tidally locked, meaning the same face of the planet is always pointed at the star, as the same side of our moon is always pointed at Earth. This creates a perpetual night side and perpetual day side on each planet. TRAPPIST-1b and c receive the most light from the star and would be the warmest. TRAPPIST-1e, f and g all orbit in the habitable zone, the area where liquid water is most likely to be detected. But any of the planets could potentially harbor liquid water, depending on their compositions. In the imagined planets shown here, TRAPPIST-1b is shown as a larger analogue to Jupiter’s moon Io. TRAPPIST-1d is depicted with a narrow band of water near the terminator, the divide between a hot, dry day and an ice-covered night side. TRAPPIST-1e and TRAPPIST-1f are both shown covered in water, but with progressively larger ice caps on the night side. TRAPPIST-1g is portrayed with an atmosphere like Neptune's, although it is still a rocky world. TRAPPIST-1h, the farthest from the star, would be the coldest. It is portrayed here as an icy world, similar to Jupiter's moon Europa, but the least is known about it.
  • TRAPPIST-1 Exoplanets Illustration
    This illustration shows the seven TRAPPIST-1 planets as they might look as viewed from Earth using a fictional, incredibly powerful telescope. The sizes and relative positions are correctly to scale: This is such a tiny planetary system that its sun, TRAPPIST-1, is not much bigger than our planet Jupiter, and all the planets are very close to the size of Earth. Their orbits all fall well within what, in our solar system, would be the orbital distance of our innermost planet, Mercury. With such small orbits, the TRAPPIST-1 planets complete a “year” in a matter of a few Earth days: 1.5 for the innermost planet, TRAPPIST-1b, and 20 for the outermost, TRAPPIST-1h. This particular arrangement of planets with a double-transit reflect an actual configuration of the system during the 21 days of observations made by NASA’s Spitzer Space Telescope in late 2016. The system has been revealed through observations from NASA's Spitzer Space Telescope and the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope, as well as other ground-based observatories. The system was named for the TRAPPIST telescope.
  • TRAPPIST-1 Exoplanets Infrared Observations
    This data plot shows infrared observations by NASAs Spitzer Space Telescope of a system of seven planets orbiting TRAPPIST-1, an ultracool dwarf star. Over 21 days, Spitzer measured the drop in light as each planet passed in front of the star. Spitzer was able to identify a total of seven rocky worlds, including three in the habitable zone where liquid water might be found. This plot shows the change in light as each planet passes in front of its star. A diagram of the layouts of the orbits is shown on the right. The study established the planets' size, distance from their sun and, for some of them, their approximate mass and density. It also established that some, if not all, these planets are tidally locked, meaning one face of the planet permanently faces their sun. The system has been revealed through observations from NASA's Spitzer Space Telescope and the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope, as well as other ground-based observatories. The system was named for the TRAPPIST telescope.
  • TRAPPIST-1 Exoplanets Statistics
    This chart shows, on the top row, artist concepts of the seven planets of TRAPPIST-1 with their orbital periods, distances from their star, radii and masses as compared to those of Earth. On the bottom row, the same numbers are displayed for the bodies of our inner solar system: Mercury, Venus, Earth and Mars. The TRAPPIST-1 planets orbit their star extremely closely, with periods ranging from 1.5 to only about 20 days. This is much shorter than the period of Mercury, which orbits our sun in about 88 days. The artist concepts show what the TRAPPIST-1 planetary system may look like, based on available data about their diameters, masses and distances from the host star. The system has been revealed through observations from NASA's Spitzer Space Telescope and the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope, as well as other ground-based observatories. The system was named for the TRAPPIST telescope. The seven planets of TRAPPIST-1 are all Earth-sized and terrestrial, according to research published in 2017 in the journal Nature. TRAPPIST-1 is an ultra-cool dwarf star in the constellation Aquarius, and its planets orbit very close to it.
  • TRAPPIST-1 Exoplanets Comparison to Our Solar System
    All seven planets discovered in orbit around the red dwarf star TRAPPIST-1 could easily fit inside the orbit of Mercury, the innermost planet of our solar system. In fact, they would have room to spare. TRAPPIST-1 also is only a fraction of the size of our sun; it isn’t much larger than Jupiter. So the TRAPPIST-1 system’s proportions look more like Jupiter and its moons than those of our solar system. The seven planets of TRAPPIST-1 are all Earth-sized and terrestrial, according to research published in 2017 in the journal Nature. TRAPPIST-1 is an ultra-cool dwarf star in the constellation Aquarius, and its planets orbit very close to it. The system has been revealed through observations from NASA's Spitzer Space Telescope and the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope, as well as other ground-based observatories. The system was named for the TRAPPIST telescope.
  • TRAPPIST-1 Exoplanets and the Habitable Zone
    The TRAPPIST-1 system contains a total of seven planets, all around the size of Earth. Three of them -- TRAPPIST-1e, f and g -- dwell in their star’s so-called “habitable zone.” The habitable zone, or Goldilocks zone, is a band around every star (shown here in green) where astronomers have calculated that temperatures are just right -- not too hot, not too cold -- for liquid water to pool on the surface of an Earth-like world. While TRAPPIST-1b, c and d are too close to be in the system’s likely habitable zone, and TRAPPIST-1h is too far away, the planets’ discoverers say more optimistic scenarios could allow any or all of the planets to harbor liquid water. In particular, the strikingly small orbits of these worlds make it likely that most, if not all of them, perpetually show the same face to their star, the way our moon always shows the same face to the Earth. This would result in an extreme range of temperatures from the day to night sides, allowing for situations not factored into the traditional habitable zone definition. The illustrations shown for the various planets depict a range of possible scenarios of what they could look like. The system has been revealed through observations from NASA's Spitzer Space Telescope and the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope, as well as other ground-based observatories. The system was named for the TRAPPIST telescope.
  • Other Earths
    NASA's Kepler mission has discovered two new planetary systems that include three super-Earth-size planets in the habitable zone, the range of distance from a star where the surface temperature of an orbiting planet might be suitable for liquid water. Two of the newly discovered planets orbit a star smaller and cooler than the sun. Kepler-62f is only 40 percent larger than Earth, making it the exoplanet closest to the size of our planet known in the habitable zone of another star. Kepler-62f is likely to have a rocky composition. Kepler-62e, orbits on the inner edge of the habitable zone and is roughly 60 percent larger than Earth. The third planet, Kepler-69c, is 70 percent larger than the size of Earth, and orbits in the habitable zone of a star similar to our sun. Astronomers are uncertain about the composition of Kepler-69c, but its orbit of 242 days around a sun-like star resembles that of our neighboring planet Venus. Scientists do not know whether life could exist on the newfound planets, but their discovery signals we are another step closer to finding a world similar to Earth around a star like our sun.