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Asteroid Belts of Just the Right Size are Friendly to Life
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By NASA
The IAU (International Astronomical Union), an international non-governmental research organization and global naming authority for celestial objects, has approved official names for features on Donaldjohanson, an asteroid NASA’s Lucy spacecraft visited on April 20. In a nod to the fossilized inspiration for the names of the asteroid and spacecraft, the IAU’s selections recognize significant sites and discoveries on Earth that further our understanding of humanity’s origins.
The asteroid was named in 2015 after paleoanthropologist Donald Johanson, discoverer of one of the most famous fossils ever found of a female hominin, or ancient human ancestor, nicknamed Lucy. Just as the Lucy fossil revolutionized our understanding of human evolution, NASA’s Lucy mission aims to revolutionize our understanding of solar system evolution by studying at least eight Trojan asteroids that share an orbit with Jupiter.
Postcard commemorating NASA’s Lucy spacecraft April 20, 2025, encounter with the asteroid Donaldjohanson. NASA’s Goddard Space Flight Center Donaldjohanson, located in the main asteroid belt between the orbits of Mars and Jupiter, was a target for Lucy because it offered an opportunity for a comprehensive “dress rehearsal” for Lucy’s main mission, with all three of its science instruments carrying out observation sequences very similar to the ones that will occur at the Trojans.
After exploring the asteroid and getting to see its features up close, the Lucy science and engineering team proposed to name the asteroid’s surface features in recognition of significant paleoanthropological sites and discoveries, which the IAU accepted.
The smaller lobe is called Afar Lobus, after the Ethiopian region where Lucy and other hominin fossils were found. The larger lobe is named Olduvai Lobus, after the Tanzanian river gorge that has also yielded many important hominin discoveries.
The asteroid’s neck, Windover Collum, which joins those two lobes, is named after the Windover Archeological Site near Cape Canaveral Space Force Station in Florida — where NASA’s Lucy mission launched in 2021. Human remains and artifacts recovered from that site revolutionized our understanding of the people who lived in Florida around 7,300 years ago.
Officially recognized names of geologic features on the asteroid Donaldjohanson. NASA Goddard/SwRI/Johns Hopkins APL Two smooth areas on the asteroid’s neck are named Hadar Regio, marking the specific site of Johanson’s discovery of the Lucy fossil, and Minatogawa Regio, after the location where the oldest known hominins in Japan were found. Select boulders and craters on Donaldjohanson are named after notable fossils ranging from pre-Homo sapiens hominins to ancient modern humans. The IAU also approved a coordinate system for mapping features on this uniquely shaped small world.
As of Sept. 9, the Lucy spacecraft was nearly 300 million miles (480 million km) from the Sun en route to its August 2027 encounter with its first Trojan asteroid called Eurybates. This places Lucy about three quarters of the way through the main asteroid belt. Since its encounter with Donaldjohanson, Lucy has been cruising without passing close to any other asteroids, and without requiring any trajectory correction maneuvers.
The team continues to carefully monitor the instruments and spacecraft as it travels farther from the Sun into a cooler environment.
Stay tuned at nasa.gov/lucy for more updates as Lucy continues its journey toward the never-before-explored Jupiter Trojan asteroids.
By Katherine Kretke
Southwest Research Institute
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What Would It Take to Say We Found Life?
We call this the podium test. What would it take for you personally to confidently stand up in front of an international audience and make that claim? When you put it in that way, I think for a lot of scientists, the bar is really high.
So of course, there would be obvious things, you know, a very clear signature of technology or a skeleton or something like that. But we think that a lot of the evidence that we might encounter first will be much more subtle. For example, chemical signs of life that have to be detected above a background of abiotic chemistry. And really, what we see might depend a lot on where we look.
On Mars, for example, the long history of exploration there gives us a lot of context for what we might find. But we’re potentially talking about samples that are billions of years old in those cases, and on Earth, those kinds of samples, the evidence of life is often degraded and difficult to detect.
On the ocean worlds of our outer solar system, so places like Jupiter’s moon Europa and Saturn’s moon Enceladus, there’s the tantalizing possibility of extant life, meaning life that’s still alive. But potentially we’re talking about exceedingly small amounts of samples that would have to be analyzed with a relatively limited amount of instrumentation that can be carried from Earth billions of miles away.
And then for exoplanets, these are planets beyond our own solar system. Really, what we’re looking for there are very large magnitude signs of life that can be detectable through a telescope from many light-years away. So changes like the oxygenation of Earth’s atmosphere or changes in surface color.
So any one of those things, if they rose to the suspicion of being evidence of life, would be really heavily scrutinized in a very sort of specific and custom way to that particular observation. But I think there are also some general principles that we can follow. And the first is just: Are we sure we’re seeing what we think we’re seeing? Many of these environments are not very well known to us, and so we need to convince ourselves that we’re actually seeing a clear signal that represents what we think it represents.
Carl Sagan once said, “Life is the hypothesis of last resort,” meaning that we ought to work hard for such a claim to rule out alternative possibilities. So what are those possibilities? One is contamination. The spacecraft and the instruments that we use to look for evidence of life are built in an environment, Earth, that is full of life. And so we need to convince ourselves that what we’re seeing is not evidence of our own life, but evidence of indigenous life.
If that’s the case, we should ask, should life of the type we’re seeing live there? And finally, we need to ask, is there any other way than life to make that thing, any of the possible abiotic processes that we know and even the ones that we don’t know? And as you can imagine, that will be quite a challenge.
Once we have a piece of evidence in hand that we really do think represents evidence of life, now we can begin to develop hypotheses. For example, do we have separate independent lines of evidence that corroborate what we’ve seen and increase our confidence of life?
Ultimately, all of this has to be looked at hard by the entire scientific community, and in that sense, I think the really operative word in our question is we. What does it take to say we found evidence of life? Because really, the answer, I think, depends on the full scientific community scrutinizing and skepticizing this observation to finally say that we scientists, we as a community and we as humanity found life.
[END VIDEO TRANSCRIPT]
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By NASA
Space changes you. It strengthens some muscles, weakens others, shifts fluids within your body, and realigns your sense of balance. NASA’s Human Research Program works to understand—and sometimes even counter—those changes so astronauts can thrive on future deep space missions.
NASA astronaut Loral O’Hara pedals on the Cycle Ergometer Vibration Isolation System (CEVIS) inside the International Space Station’s Destiny laboratory module.NASA Astronauts aboard the International Space Station work out roughly two hours a day to protect bone density, muscle strength and the cardiovascular system, but the longer they are in microgravity, the harder it can be for the brain and body to readapt to gravity’s pull. After months in orbit, returning astronauts often describe Earth as heavy, loud, and strangely still. Some reacclimate within days, while other astronauts take longer to fully recover.
Adjusting to Gravity
NASA’s SpaceX Crew-7 astronaut Jasmin Moghbeli after landing in the Gulf of America on March 12, 2024, completing 197 days in space.NASA/Joel Kowsky The crew of NASA’s SpaceX Crew-7 mission— NASA astronaut Jasmin Moghbeli, ESA (European Space Agency) astronaut Andreas Mogensen, JAXA (Japan Aerospace Exploration Agency) astronaut Satoshi Furukawa, and Roscosmos cosmonaut Konstantin Borisov—landed in March 2024 after nearly 200 days in space. One of the first tests volunteer crew members completed was walking with their eyes open and then closed.
“With eyes closed, it was almost impossible to walk in a straight line,” Mogensen said. In space, vision is the primary way astronauts orient themselves, but back on Earth, the brain must relearn how to use inner-ear balance signals. Moghbeli joked her first attempt at the exercise looked like “a nice tap dance.”
“I felt very wobbly for the first two days,” Moghbeli said. “My neck was very tired from holding up my head.” She added that, overall, her body readapted to gravity quickly.
Astronauts each recover on their own timetable and may encounter different challenges. Mogensen said his coordination took time to return. Furukawa noted that he could not look down without feeling nauseated. “Day by day, I recovered and got more stable,” he said.
NASA astronaut Loral O’Hara after landing in a remote area near the town of Zhezkazgan, Kazakhstan, on April 6, 2024.NASA/Bill Ingalls NASA astronaut Loral O’Hara returned in April 2024 after 204 days in space. She said she felt almost completely back to normal a week after returning to Earth. O’Hara added that her prior experience as an ocean engineer gave her insight into space missions. “Having those small teams in the field working with a team somewhere else back on shore with more resources is a good analog for the space station and all the missions we’re hoping to do in the future,” she said.
NASA astronaut Nichole Ayers, who flew her first space mission with NASA’s SpaceX Crew-10, noted that the brain quickly adapts to weightlessness by tuning out the vestibular system, which controls balance. “Then, within days of being back on Earth, it remembers again—it’s amazing how fast the body readjusts,” she said.
Expedition 69 NASA astronaut Frank Rubio outside the Soyuz MS-23 spacecraft after landing near the town of Zhezkazgan, Kazakhstan, on Sept. 27, 2023. NASA/Bill Ingalls When NASA astronaut Frank Rubio landed in Kazakhstan in September 2023, he had just completed a record 371-day mission—the longest single U.S. spaceflight.
Rubio said his body adjusted to gravity right away, though his feet and lower back were sore after more than a year without weight on them. Thanks to consistent workouts, Rubio said he felt mostly recovered within a couple of weeks.
Mentally, extending his mission from six months to a year was a challenge. “It was a mixed emotional roller coaster,” he said, but regular video calls with family kept him grounded. “It was almost overwhelming how much love and support we received.”
Crew-8 astronauts Matt Dominick, Jeanette Epps, Michael Barratt, and cosmonaut Alexander Grebenkin splashed down in October 2024 after 235 days on station. Dominick found sitting on hard surfaces uncomfortable at first. Epps felt the heaviness of Earth immediately. “You have to move and exercise every day, regardless of how exhausted you feel,” she said.
Barratt, veteran astronaut and board certified in internal and aerospace medicine, explained that recovery differs for each crew member, and that every return teaches NASA something new.
Still a Challenge, Even for Space Veterans
NASA astronaut Suni Williams is helped out of a SpaceX Dragon spacecraft aboard the SpaceX recovery ship after splashing down off the coast of Tallahassee, Florida, March 18, 2025. NASA/Keegan Barber Veteran NASA astronauts Suni Williams and Butch Wilmore returned from a nine-month mission with Crew-9 in early 2025. Despite her extensive spaceflight experience, Williams said re-adapting to gravity can still be tough. “The weight and heaviness of things is surprising,” she said. Like others, she pushed herself to move daily to regain strength and balance.
NASA astronaut Don Pettit arrives at Ellington Field in Houston on April 20, 2025, after returning to Earth aboard the Soyuz MS-25 spacecraft. NASA/Robert Markowitz NASA astronaut Don Pettit, also a veteran flyer, came home in April 2025 after 220 days on the space station. At 70 years old, he is NASA’s oldest active astronaut—but experience did not make gravity gentler. During landing, he says he was kept busy, “emptying the contents of my stomach onto the steppes of Kazakhstan.” Microgravity had eased the aches in his joints and muscles, but Earth’s pull brought them back all at once.
Pettit said his recovery felt similar to earlier missions. “I still feel like a little kid inside,” he said. The hardest part, he explained, isn’t regaining strength in big muscle groups, but retraining the small, often-overlooked muscles unused in space. “It’s a learning process to get used to gravity again.”
Recovery happens day by day—with help from exercise, support systems, and a little humor. No matter how long an astronaut is in space, every journey back to Earth is unique.
The Human Research Program help scientists understand how spaceflight environments affect astronaut health and performance and informs strategies to keep crews healthy for future missions to the Moon, Mars, and beyond. The program studies astronauts before, during, and after spaceflight to learn how the human body adapts to living and working in space. It also collects data through Earth-based analog missions that can help keep astronauts safer for future space exploration.
To learn more about how microgravity affects the human body and develop new ways to help astronauts stay healthy, for example, its scientists conduct bedrest studies – asking dozens of volunteers to spend 60 days in bed with their heads tilted down at a specific angle. Lying in this position tricks the body into responding as it would if the body was in space which allows scientists to trial interventions to hopefully counter some of microgravity’s effects. Such studies, through led by NASA, occur at the German Aerospace Center’s Cologne campus at a facility called :envihab – a combination of “environment” and “habitat.”
Additional Earth-based insights come from the Crew Health and Performance Exploration Analog (CHAPEA) and the Human Exploration Research Analog (HERA) at NASA’s Johnson Space Center in Houston. Both analogs recreate the remote conditions and scenarios of deep space exploration here on Earth with volunteer crews who agree to live and work in the isolation of ground-based habitats and endure challenges like delayed communication that simulates the type of interactions that will occur during deep space journeys to and from Mars. Findings from these ground-based missions and others will help NASA refine its future interventions, strategies, and protocols for astronauts in space.
NASA and its partners have supported humans continuously living and working in space since November 2000. After nearly 25 years of continuous human presence, the space station remains the sole space-based proving ground for training and research for deep space missions, enabling NASA’s Artemis campaign, lunar exploration, and future Mars missions.
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By NASA
Advancing Single-Photon Sensing Image Sensors to Enable the Search for Life Beyond Earth
A NASA-sponsored team is advancing single-photon sensing Complementary Metal-Oxide-Semiconductor (CMOS) detector technology that will enable future NASA astrophysics space missions to search for life on other planets. As part of their detector maturation program, the team is characterizing sensors before, during, and after high-energy radiation exposure; developing novel readout modes to mitigate radiation-induced damage; and simulating a near-infrared CMOS pixel prototype capable of detecting individual photons.
Single-photon sensing and photon-number resolving CMOS image sensors: a 9.4 Mpixel sensor (left) and a 16.7 Mpixel sensor (right). Credit: CfD, RIT Are we alone in the universe? This age-old question has inspired scientific exploration for centuries. If life on other planets evolves similarly to life on Earth, it can imprint its presence in atmospheric spectral features known asbiosignatures. They include absorption and emission lines in the spectrum produced by oxygen, carbon dioxide, methane, and other molecules that could indicate conditions which can support life. A future NASA astrophysics mission, the Habitable Worlds Observatory (HWO), will seek to find biosignatures in the ultraviolet, optical, and near-infrared (NIR) spectra of exoplanet atmospheres to look for evidence that life may exist elsewhere in the universe.
HWO will need highly sensitive detector technology to detect these faint biosignatures on distant exoplanets. The Single-Photon Sensing Complementary Metal-Oxide-Semiconductor (SPSCMOS) image sensor is a promising technology for this application. These silicon-based sensors can detect and resolve individual optical-wavelength photons using a low-capacitance, high-gain floating diffusion sense node. They operate effectively over a broad temperature range, including at room temperature. They have near-zero read noise, are tolerant to radiation, and generate very little unwanted signal—such as dark current. When cooled to 250 K, the dark current drops to just one electron every half-hour. If either the read noise or dark current is too high, the sensor will fail to detect the faint signals that biosignatures produce.
A research team at the Rochester Institute of Technology (RIT) Center for Detectors (CfD) is accelerating the readiness of these SPSCMOS sensors for use in space missions through detector technology maturation programs funded by NASA’s Strategic Astrophysics Technology and Early Stage Innovations solicitations. These development programs include several key goals:
Characterize critical detector performance metrics like dark current, quantum efficiency, and read noise before, during, and after exposure to high-energy radiation Develop new readout modes for these sensors to mitigate effects from short-term and long-term radiation damage Design a new NIR version of the sensor using Technology Computer-Aided Design (TCAD) software SPSCMOS sensors operate similarly to traditional CMOS image sensors but are optimized to detect individual photons—an essential capability for ultra-sensitive space-based observations, such as measuring the gases in the atmospheres of exoplanets. Incoming photons enter the sensor and generate free charges (electrons) in the sensor material. These charges collect in a pixel’s storage well and eventually transfer to a low-capacitance component called the floating diffusion (FD) sense node where each free charge causes a large and resolved voltage shift. This voltage shift is then digitized to read the signal.
Experiments that measure sensor performance in a space relevant environment use a vacuum Dewar and a thermally-controlled mount to allow precise tuning of the sensors temperature. The Dewar enables testing at conditions that match the expected thermal environment of the HWO instrument, and can even cool the sensor and its on-chip circuits to temperatures colder than any prior testing reported for this detector family. These tests are critical for revealing performance limitations with respect to detector metrics like dark current, quantum efficiency, and read noise. As temperatures change, the electrical properties of on-chip circuits can also change, which affects the read out of charge in a pixel.
The two figures show results for SPSCMOS devices. The figure on the left shows a photon counting histogram with peaks that correspond to photon number. The figure on the right shows the dark current for a SPSCMOS device before and after exposure to 50 krad of 60 MeV protons. Credit: CfD, RIT The radiation-rich environment for HWO will cause temporary and permanent effects in the sensor. These effects can corrupt the signal measured in a pixel, interrupt sensor clocking and digital logic, and can cause cumulative damage that gradually degrades sensor performance. To mitigate the loss of detector sensitivity throughout a mission lifetime, the RIT team is developing new readout modes that are not available in commercial CMOS sensors. These custom modes sample the signal over time (a “ramp” acquisition) to enable the detection and removal of cosmic ray artifacts. In one mode, when the system identifies an artifact, it segments the signal ramp and selectively averages the segments to reconstruct the original signal—preserving scientific data that would otherwise be lost. In addition, a real-time data acquisition system monitors the detector’s power consumption, which may change from the accumulation of damage throughout a mission. The acquisition system records these shifts and communicates with the detector electronics to adjust voltages and maintain nominal operation. These radiation damage mitigation strategies will be evaluated during a number of test programs at ground-based radiation facilities. The tests will help identify unique failure mechanisms that impact SPSCMOS technology when it is exposed to radiation equivalent to the dose expected for HWO.
Custom acquisition electronics (left) that will control the sensors during radiation tests, and an image captured using this system (right). Credit: CfD, RIT While existing SPSCMOS sensors are limited to detecting visible light due to their silicon-based design, the RIT team is developing the world’s first NIR single-photon photodiode based on the architecture used in the optical sensors. The photodiode design starts as a simulation in TCAD software to model the optical and electrical properties of the low-capacitance CMOS architecture. The model simulates light-sensitive circuits using both silicon and Mercury Cadmium Telluride (HgCdTe or MCT) material to determine how well the pixel would measure photo-generated charge if a semiconductor foundry physically fabricated it. It has 2D and 3D device structures that convert light into electrical charge, and circuits to control charge transfer and signal readout with virtual probes that can measure current flow and electric potential. These simulations help to evaluate the key mechanisms like the conversion of light into electrons, storing and transferring the electrons, and the output voltage of the photodiode sampling circuit.
In addition to laboratory testing, the project includes performance evaluations at a ground-based telescope. These tests allow the sensor to observe astronomical targets that cannot be fully replicated in lab. Star fields and diffuse nebulae challenge the detector’s full signal chain under real sky backgrounds with faint flux levels, field-dependent aberrations, and varying seeing conditions. These observations help identify performance limitations that may not be apparent in controlled laboratory measurements.
In January 2025, a team of researchers led by PhD student Edwin Alexani used an SPSCMOS-based camera at the C.E.K. Mees Observatory in Ontario County, New York. They observed star cluster M36 to evaluate the sensor’s photometric precision, and the Bubble Nebula in a narrow-band H-alpha filter. The measured dark current and read noise were consistent with laboratory results.
The team observed photometric reference stars to estimate the quantum efficiency (QE) or the ability for the detector to convert photons into signal. The calculated QE agreed with laboratory measurements, despite differences in calibration methods.
The team also observed the satellite STARLINK-32727 as it passed through the telescope’s field of view and measured negligible persistent charge—residual signal that can remain in detector pixels after exposure to a bright source. Although the satellite briefly produced a bright streak across several pixels due to reflected sunlight, the average latent charge in affected pixels was only 0.03 e–/pix – well below both the sky-background and sensor’s read noise.
Images captured at the C.E.K. Mees Observatory. Left: The color image shows M36 in the Johnson color filters B (blue), V (green), and R (red) bands (left). Right: Edwin Alexani and the SPSCMOS camera (right). Credit: : CfD, RIT As NASA advances and matures the HWO mission, SPSCMOS technology promises to be a game-changer for exoplanet and general astrophysics research. These sensors will enhance our ability to detect and analyze distant worlds, bringing us one step closer to answering one of humanity’s most profound questions: are we alone?
For additional details, see the entry for this project on NASA TechPort.
Project Lead(s): Dr. Donald F. Figer, Future Photon Initiative and Center for Detectors, Rochester Institute of Technology (RIT), supported by engineer Justin Gallagher and a team of students.
Sponsoring Organization(s): NASA Astrophysics Division, Strategic Astrophysics Technology (SAT) Program and NASA Space Technology Mission Directorate (STMD), Early Stage Innovations (ESI) Program
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Explore Hubble Science Hubble Space Telescope As NASA Missions Study… Hubble Home Overview About Hubble The History of Hubble Hubble Timeline Why Have a Telescope in Space? Hubble by the Numbers At the Museum FAQs Impact & Benefits Hubble’s Impact & Benefits Science Impacts Cultural Impact Technology Benefits Impact on Human Spaceflight Astro Community Impacts Science Hubble Science Science Themes Science Highlights Science Behind Discoveries Hubble’s Partners in Science Universe Uncovered AI and Hubble Science Explore the Night Sky Observatory Hubble Observatory Hubble Design Mission Operations Missions to Hubble Hubble vs Webb Team Hubble Team Career Aspirations Hubble Astronauts Multimedia Images Videos Sonifications Podcasts e-Books Online Activities 3D Hubble Models Lithographs Fact Sheets Posters Hubble on the NASA App Glossary News Hubble News Social Media Media Resources More 35th Anniversary Online Activities 4 min read
As NASA Missions Study Interstellar Comet, Hubble Makes Size Estimate
Hubble captured this image of the interstellar comet 3I/ATLAS on July 21, 2025, when the comet was 277 million miles from Earth. Hubble shows that the comet has a teardrop-shaped cocoon of dust coming off its solid, icy nucleus. Image: NASA, ESA, David Jewitt (UCLA); Image Processing: Joseph DePasquale (STScI) A team of astronomers has taken the sharpest-ever picture of the unexpected interstellar comet 3I/ATLAS using the crisp vision of NASA’s Hubble Space Telescope. Hubble is one of many missions across NASA’s fleet of space telescopes slated to observe this comet, together providing more information about its size and physical properties. While the comet poses no threat to Earth, NASA’s space telescopes help support the agency’s ongoing mission to find, track, and better understand near-Earth objects.
Hubble’s observations allow astronomers to more accurately estimate the size of the comet’s solid, icy nucleus. The upper limit on the diameter of the nucleus is 3.5 miles (5.6 kilometers), though it could be as small as 1,000 feet (320 meters) across, researchers report. Though the Hubble images put tighter constraints on the size of the nucleus compared to previous ground-based estimates, the solid heart of the comet presently cannot be directly seen, even by Hubble. Observations from other NASA missions including the James Webb Space Telescope, TESS (Transiting Exoplanet Survey Satellite), and the Neil Gehrels Swift Observatory, as well as NASA’s partnership with the W.M. Keck Observatory, will help further refine our knowledge about the comet, including its chemical makeup.
Hubble also captured a dust plume ejected from the Sun-warmed side of the comet, and the hint of a dust tail streaming away from the nucleus. Hubble’s data yields a dust-loss rate consistent with comets that are first detected around 300 million miles from the Sun. This behavior is much like the signature of previously seen Sun-bound comets originating within our solar system.
The big difference is that this interstellar visitor originated in some other solar system elsewhere in our Milky Way galaxy.
3I/ATLAS is traveling through our solar system at a staggering 130,000 miles (209,000 kilometers) per hour, the highest velocity ever recorded for a solar system visitor. This breathtaking sprint is evidence that the comet has been drifting through interstellar space for many billions of years. The gravitational slingshot effect from innumerable stars and nebulae the comet passed added momentum, ratcheting up its speed. The longer 3I/ATLAS was out in space, the higher its speed grew.
“No one knows where the comet came from. It’s like glimpsing a rifle bullet for a thousandth of a second. You can’t project that back with any accuracy to figure out where it started on its path,” said David Jewitt of the University of California, Los Angeles, science team leader for the Hubble observations.
The paper will be published in The Astrophysical Journal Letters. It is already available on Astro-ph.
New Evidence for Population of Wandering Space Relics
“This latest interstellar tourist is one of a previously undetected population of objects bursting onto the scene that will gradually emerge,” said Jewitt. “This is now possible because we have powerful sky survey capabilities that we didn’t have before. We’ve crossed a threshold.”
This comet was discovered by the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) on July 1, 2025, at a distance of 420 million miles from the Sun. ATLAS is an asteroid impact early warning system developed by the University of Hawai’i.
In the meantime, other NASA missions will provide new insight into this third interstellar interloper, helping refine our understanding of these objects for the benefit of all. 3I/ATLAS should remain visible to ground-based telescopes through September, after which it will pass too close to the Sun to observe, and is expected to reappear on the other side of the Sun by early December.
The Hubble Space Telescope has been operating for more than three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.
To learn more about Hubble, visit: https://science.nasa.gov/hubble
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Comet 3I/ATLAS
Hubble captured this image of the interstellar comet 3I/ATLAS on July 21, 2025, when the comet was 277 million miles from Earth. Hubble shows that the comet has a teardrop-shaped cocoon of dust coming off its solid, icy nucleus.
Comet 3I/ATLAS Compass Image
This image of interstellar comet 3I/ATLAS was captured by the Hubble Space Telescope’s Wide Field Camera on July 21, 2025. The scale bar is labeled in arcseconds, which is a measure of angular distance on the sky. One arcsecond is equal an angular measurement of 1/3600 of o…
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Last Updated Aug 07, 2025 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Contact Media Claire Andreoli
NASA’s Goddard Space Flight Center
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claire.andreoli@nasa.gov
Ray Villard
Space Telescope Science Institute
Baltimore, Maryland
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Science Paper: Hubble Space Telescope Observations of the Interstellar Interloper 3I/ATLAS, PDF (1.57 MB)
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