Jump to content

NASA Study: Asteroid’s Orbit, Shape Changed After DART Impact


Recommended Posts

  • Publishers
Posted
1-dimorphos-before-impact-dart.png?w=170
The asteroid Dimorphos was captured by NASA’s DART mission just two seconds before the spacecraft struck its surface on Sept. 26, 2022. Observations of the asteroid before and after impact suggest it is a loosely packed “rubble pile” object.
NASA/Johns Hopkins APL

After NASA’s historic Double Asteroid Redirection Test, a JPL-led study has shown that the shape of asteroid Dimorphos has changed and its orbit has shrunk.

When NASA’s DART (Double Asteroid Redirection Test) deliberately smashed into a 560-foot-wide (170-meter-wide) asteroid on Sept. 26, 2022, it made its mark in more ways than one. The demonstration showed that a kinetic impactor could deflect a hazardous asteroid should one ever be on a collision course with Earth. Now a new study published in the Planetary Science Journal shows the impact changed not only the motion of the asteroid, but also its shape.

DART’s target, the asteroid Dimorphos, orbits a larger near-Earth asteroid called Didymos. Before the impact, Dimorphos had a roughly symmetrical “oblate spheroid” shape – like a squashed ball that is wider than it is tall. With a well-defined, circular orbit at a distance of about 3,900 feet (1,189 meters) from Didymos, Dimorphos took 11 hours and 55 minutes to complete one loop around Didymos.

“When DART made impact, things got very interesting,” said Shantanu Naidu, a navigation engineer at NASA’s Jet Propulsion Laboratory in Southern California, who led the study. “Dimorphos’ orbit is no longer circular: Its orbital period” – the time it takes to complete a single orbit – “is now 33 minutes and 15 seconds shorter. And the entire shape of the asteroid has changed, from a relatively symmetrical object to a ‘triaxial ellipsoid’ – something more like an oblong watermelon.”

This illustration shows the approximate shape change that the asteroid Dimorphos experienced after DART hit it. Before impact, left, the asteroid was shaped like a squashed ball; after impact it took on a more elongated shape, like a watermelon.
This illustration shows the approximate shape change that the asteroid Dimorphos experienced after DART hit it. Before impact, left, the asteroid was shaped like a squashed ball; after impact it took on a more elongated shape, like a watermelon.
NASA/JPL-Caltech

Dimorphos Damage Report

Naidu’s team used three data sources in their computer models to deduce what had happened to the asteroid after impact. The first source was aboard DART: The spacecraft captured images as it approached the asteroid and sent them back to Earth via NASA’s Deep Space Network (DSN). These images provided close-up measurements of the gap between Didymos and Dimorphos while also gauging the dimensions of both asteroids just prior to impact.

The second data source was the DSN’s Goldstone Solar System Radar, located near Barstow, California, which bounced radio waves off both asteroids to precisely measure the position and velocity of Dimorphos relative to Didymos after impact. Radar observations quickly helped NASA conclude that DART’s effect on the asteroid greatly exceeded the minimum expectations.

The third and most significant source of data: ground telescopes around the world that measured both asteroids’ “light curve,” or how the sunlight reflecting off the asteroids’ surfaces changed over time. By comparing the light curves before and after impact, the researchers could learn how DART altered Dimorphos’ motion.

As Dimorphos orbits, it periodically passes in front of and then behind Didymos. In these so-called “mutual events,” one asteroid can cast a shadow on the other, or block our view from Earth. In either case, a temporary dimming – a dip in the light curve – will be recorded by telescopes.

“We used the timing of this precise series of light-curve dips to deduce the shape of the orbit, and because our models were so sensitive, we could also figure out the shape of the asteroid,” said Steve Chesley, a senior research scientist at JPL and study co-author. The team found Dimorphos’ orbit is now slightly elongated, or eccentric. “Before impact,” Chesley continued, “the times of the events occurred regularly, showing a circular orbit. After impact, there were very slight timing differences, showing something was askew. We never expected to get this kind of accuracy.”

The models are so precise, they even show that Dimorphos rocks back and forth as it orbits Didymos, Naidu said.

Orbital Evolution

The team’s models also calculated how Dimorphos’ orbital period evolved. Immediately after impact, DART reduced the average distance between the two asteroids, shortening Dimorphos’ orbital period by 32 minutes and 42 seconds, to 11 hours, 22 minutes, and 37 seconds.

Over the following weeks, the asteroid’s orbital period continued to shorten as Dimorphos lost more rocky material to space, finally settling at 11 hours, 22 minutes, and 3 seconds per orbit – 33 minutes and 15 seconds less time than before impact. This calculation is accurate to within 1 ½ seconds, Naidu said. Dimorphos now has a mean orbital distance from Didymos of about 3,780 feet (1,152 meters) – about 120 feet (37 meters) closer than before impact.

“The results of this study agree with others that are being published,” said Tom Statler, lead scientist for solar system small bodies at NASA Headquarters in Washington. “Seeing separate groups analyze the data and independently come to the same conclusions is a hallmark of a solid scientific result. DART is not only showing us the pathway to an asteroid-deflection technology, it’s revealing new fundamental understanding of what asteroids are and how they behave.”

These results and observations of the debris left after impact indicate that Dimorphos is a loosely packed “rubble pile” object, similar to asteroid Bennu. ESA’s (European Space Agency) Hera mission, planned to launch in October 2024, will travel to the asteroid pair to carry out a detailed survey and confirm how DART reshaped Dimorphos.

More About the Mission

DART was designed, built, and operated by the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, for NASA’s Planetary Defense Coordination Office, which oversees the agency’s ongoing efforts in planetary defense. DART was humanity’s first mission to intentionally move a celestial object.

JPL, a division of Caltech in Pasadena, California, manages the DSN for NASA’s Space Communications and Navigation (SCaN) program within the Space Operations Mission Directorate at the agency’s headquarters in Washington.

News Media Contacts

Ian J. O’Neill
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-2649
ian.j.oneill@jpl.nasa.gov

Karen Fox / Charles Blue
NASA Headquarters
karen.c.fox@nasa.gov / charles.e.blue@nasa.gov

2024-029

View the full article

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Topics

    • By NASA
      Former Johnson Director Jefferson Howell July 3, 2025
      Jefferson Davis Howell, Jr., former director of NASA’s Johnson Space Center in Houston, died July 2, in Bee Cave, Texas. He was 85 years old.
      Howell was a champion of the construction of the International Space Station, working on a deadline to complete the orbiting lab by 2004. He oversaw four space shuttle crews delivering equipment and hardware to reach that goal. He also served as director during a pivotal moment for the agency: the loss of STS-107 and the crew of space shuttle Columbia. He made it his personal responsibility to meet with the families, look after them, and attend memorial services, all while keeping the families informed of the accident investigation as it unfolded.
      “Gen. Howell led NASA Johnson through one of the most difficult chapters in our history, following the loss of Columbia and her crew,” said acting associate administrator Vanessa Wyche. “He brought strength and steady direction, guiding the workforce with clarity and compassion. He cared deeply for the people behind the mission and shared his leadership skills generously with the team. We extend our heartfelt condolences to his family and all who knew and loved him.”
      At the time of his selection as director, he was serving as senior vice president with Science Applications International Corporation (SAIC) as the program manager for the safety, reliability, and quality assurance contract at Johnson. Following the accident, he made it his mission to improve the relationship between the civil servant and contractor workforce. He left his position and the agency, in October 2005, shortly after the Return-to-Flight mission of STS-114.
      “General Howell stepped into leadership at Johnson during a pivotal time, as the International Space Station was just beginning to take shape. He led and supported NASA’s successes not only in space but here on the ground — helping to strengthen the center’s culture and offering guidance through both triumph and tragedy,” said Steve Koerner, Johnson Space Center’s acting director. “On behalf of NASA’s Johnson Space Center, we offer our deepest sympathies to his family, friends, and all those who had the privilege of working alongside him. The impact of his legacy will continue to shape Johnson for decades to come.”
      The Victoria, Texas, native was a retired lieutenant general in the U.S. Marine Corps with a decorated military career prior to his service at NASA. He flew more than 300 combat missions in Vietnam and Thailand.
      Howell is survived by his wife Janel and two children. A tree dedication will be held at NASA Johnson’s memorial grove in the coming year.
      -end-
      Chelsey Ballarte
      Johnson Space Center, Houston
      281-483-5111
      chelsey.n.ballarte@nasa.gov
      View the full article
    • By NASA
      5 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      The Swept Wing Flow Test model, known as SWiFT, with pressure sensitive paint applied, sports a pink glow under ultraviolet lights while tested during 2023 in a NASA wind tunnel at Langley Research Center in Virginia.NASA / Dave Bowman Many of us grew up using paint-by-number sets to create beautiful color pictures.
      For years now, NASA engineers studying aircraft and rocket designs in wind tunnels have flipped that childhood pastime, using computers to generate images from “numbers-by-paint” – pressure sensitive paint (PSP), that is.
      Now, advances in the use of high-speed cameras, supercomputers, and even more sensitive PSP have made this numbers-by-paint process 10,000 times faster while creating engineering visuals with 1,000 times higher resolution.
      So, what’s the big difference exactly between the “old” capability in use at NASA for more than a decade and the “new?”
      “The key is found by adding a single word in front of PSP, namely ‘unsteady’ pressure sensitive paint, or uPSP,” said E. Lara Lash, an aerospace engineer from NASA’s Ames Research Center in California’s Silicon Valley.
      With PSP, NASA researchers study the large-scale effects of relatively smooth air flowing over the wings and body of aircraft. Now with uPSP, they are able to see in finer detail what happens when more turbulent air is present – faster and better than ever before.
      In some cases with the new capability, researchers can get their hands on the wind tunnel data they’re looking for within 20 minutes. That’s quick enough to allow engineers to adjust their testing in real time.
      Usually, researchers record wind tunnel data and then take it back to their labs to decipher days or weeks later. If they find they need more data, it can take additional weeks or even months to wait in line for another turn in the wind tunnel.
      “The result of these improvements provides a data product that is immediately useful to aerodynamic engineers, structural engineers, or engineers from other disciplines,” Lash said.
      Robert Pearce, NASA’s associate administrator for aeronautics, who recently saw a demonstration of uPSP-generated data displayed at Ames, hailed the new tool as a national asset that will be available to researchers all over the country.
      “It’s a unique NASA innovation that isn’t offered anywhere else,” Pearce said. “It will help us maintain NASA’s world leadership in wind tunnel capabilities.”
      A technician sprays unsteady pressure sensitive paint onto the surface of a small model of the Space Launch System in preparation for testing in a NASA wind tunnel.NASA / Dave Bowman How it Works
      With both PSP and uPSP, a unique paint is applied to scale models of aircraft or rockets, which are mounted in wind tunnels equipped with specific types of lights and cameras.
      When illuminated during tests, the paint’s color brightness changes depending on the levels of pressure the model experiences as currents of air rush by. Darker shades mean higher pressure; lighter shades mean lower pressure.
      Cameras capture the brightness intensity and a supercomputer turns that information into a set of numbers representing pressure values, which are made available to engineers to study and glean what truths they can about the vehicle design’s structural integrity.
      “Aerodynamic forces can vibrate different parts of the vehicle to different degrees,” Lash said. “Vibrations could damage what the vehicle is carrying or can even lead to the vehicle tearing itself apart. The data we get through this process can help us prevent that.”
      Traditionally, pressure readings are taken using sensors connected to little plastic tubes strung through a model’s interior and poking up through small holes in key places, such as along the surface of a wing or the fuselage. 
      Each point provides a single pressure reading. Engineers must use mathematical models to estimate the pressure values between the individual sensors.
      With PSP, there is no need to estimate the numbers. Because the paint covers the entire model, its brightness as seen by the cameras reveals the pressure values over the whole surface.
      A four-percent scale model of the Space Launch System rocket is tested in 2017 using unsteady Pressure Sensitive Paint inside the 11-foot by 11-foot Unitary Plan Wind Tunnel at NASA’s Ames Research Center in California.NASA / Dominic Hart Making it Better
      The introduction, testing, and availability of uPSP is the result of a successful five-year-long effort, begun in 2019, in which researchers challenged themselves to significantly improve the PSP’s capability with its associated cameras and computers.
      The NASA team’s desire was to develop and demonstrate a better process of acquiring, processing, and visualizing data using a properly equipped wind tunnel and supercomputer, then make the tool available at NASA wind tunnels across the country.
      The focus during a capability challenge was on NASA’s Unitary Plan Facility’s 11-foot transonic wind tunnel, which the team connected to the nearby NASA Advanced Supercomputing Facility, both located at Ames.
      Inside the wind tunnel, a scale model of NASA’s Space Launch System rocket served as the primary test subject during the challenge period.
      Now that the agency has completed its Artemis I uncrewed lunar flight test mission, researchers can match the flight-recorded data with the wind tunnel data to see how well reality and predictions compare.
      With the capability challenge officially completed at the end of 2024, the uPSP team is planning to deploy it to other wind tunnels and engage with potential users with interests in aeronautics or spaceflight.
      “This is a NASA capability that we have, not only for use within the agency, but one that we can offer industry, academia, and other government agencies to come in and do research using these new tools,” Lash said.
      NASA’s Aerosciences Evaluation and Test Capabilities portfolio office, an organization managed under the agency’s Aeronautics Research Mission Directorate, oversaw the development of the uPSP capability.
      Watch this uPSP Video
      About the Author
      Jim Banke
      Managing Editor/Senior WriterJim Banke is a veteran aviation and aerospace communicator with more than 40 years of experience as a writer, producer, consultant, and project manager based at Cape Canaveral, Florida. He is part of NASA Aeronautics' Strategic Communications Team and is Managing Editor for the Aeronautics topic on the NASA website.
      Facebook logo @NASA@NASAaero@NASA_es @NASA@NASAaero@NASA_es Instagram logo @NASA@NASAaero@NASA_es Linkedin logo @NASA Explore More
      6 min read By Air and by Sea: Validating NASA’s PACE Ocean Color Instrument
      Article 1 week ago 3 min read NASA Intern Took Career from Car Engines to Cockpits
      Article 1 week ago 4 min read NASA Tech to Use Moonlight to Enhance Measurements from Space
      Article 2 weeks ago Keep Exploring Discover More Topics From NASA
      Missions
      Artemis
      Aeronautics STEM
      Explore NASA’s History
      Share
      Details
      Last Updated Jul 03, 2025 EditorJim BankeContactJim Bankejim.banke@nasa.gov Related Terms
      Aeronautics Aeronautics Research Mission Directorate Aerosciences Evaluation Test Capabilities Ames Research Center Flight Innovation Glenn Research Center Langley Research Center Transformational Tools Technologies
      View the full article
    • By NASA
      5 min read
      How NASA’s SPHEREx Mission Will Share Its All-Sky Map With the World 
      NASA’s SPHEREx mission will map the entire sky in 102 different wavelengths, or colors, of infrared light. This image of the Vela Molecular Ridge was captured by SPHEREx and is part of the mission’s first ever public data release. The yellow patch on the right side of the image is a cloud of interstellar gas and dust that glows in some infrared colors due to radiation from nearby stars. NASA/JPL-Caltech NASA’s newest astrophysics space telescope launched in March on a mission to create an all-sky map of the universe. Now settled into low-Earth orbit, SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer) has begun delivering its sky survey data to a public archive on a weekly basis, allowing anyone to use the data to probe the secrets of the cosmos.
      “Because we’re looking at everything in the whole sky, almost every area of astronomy can be addressed by SPHEREx data,” said Rachel Akeson, the lead for the SPHEREx Science Data Center at IPAC. IPAC is a science and data center for astrophysics and planetary science at Caltech in Pasadena, California.
      Almost every area of astronomy can be addressed by SPHEREx data.
      Rachel Akeson
      SPHEREx Science Data Center Lead
      Other missions, like NASA’s now-retired WISE (Wide-field Infrared Survey Explorer), have also mapped the entire sky. SPHEREx builds on this legacy by observing in 102 infrared wavelengths, compared to WISE’s four wavelength bands.
      By putting the many wavelength bands of SPHEREx data together, scientists can identify the signatures of specific molecules with a technique known as spectroscopy. The mission’s science team will use this method to study the distribution of frozen water and organic molecules — the “building blocks of life” — in the Milky Way.
      This animation shows how NASA’s SPHEREx observatory will map the entire sky — a process it will complete four times over its two-year mission. The telescope will observe every point in the sky in 102 different infrared wavelengths, more than any other all-sky survey. SPHEREx’s openly available data will enable a wide variety of astronomical studies. Credit: NASA/JPL-Caltech The SPHEREx science team will also use the mission’s data to study the physics that drove the universe’s expansion following the big bang, and to measure the amount of light emitted by all the galaxies in the universe over time. Releasing SPHEREx data in a public archive encourages far more astronomical studies than the team could do on their own.
      “By making the data public, we enable the whole astronomy community to use SPHEREx data to work on all these other areas of science,” Akeson said.
      NASA is committed to the sharing of scientific data, promoting transparency and efficiency in scientific research. In line with this commitment, data from SPHEREx appears in the public archive within 60 days after the telescope collects each observation. The short delay allows the SPHEREx team to process the raw data to remove or flag artifacts, account for detector effects, and align the images to the correct astronomical coordinates.
      The team publishes the procedures they used to process the data alongside the actual data products. “We want enough information in those files that people can do their own research,” Akeson said.
      One of the early test images captured by NASA’s SPHEREx mission in April 2025. This image shows a section of sky in one infrared wavelength, or color, that is invisible to the human eye but is represented here in a visible color. This particular wavelength (3.29 microns) reveals a cloud of dust made of a molecule similar to soot or smoke. NASA/JPL-Caltech This image from NASA’s SPHEREx shows the same region of space in a different infrared wavelength (0.98 microns), once again represented by a color that is visible to the human eye. The dust cloud has vanished because the molecules that make up the dust — polycyclic aromatic hydrocarbons — do not radiate light in this color. NASA/JPL-Caltech




      During its two-year prime mission, SPHEREx will survey the entire sky twice a year, creating four all-sky maps. After the mission reaches the one-year mark, the team plans to release a map of the whole sky at all 102 wavelengths.
      In addition to the science enabled by SPHEREx itself, the telescope unlocks an even greater range of astronomical studies when paired with other missions. Data from SPHEREx can be used to identify interesting targets for further study by NASA’s James Webb Space Telescope, refine exoplanet parameters collected from NASA’s TESS (Transiting Exoplanet Survey Satellite), and study the properties of dark matter and dark energy along with ESA’s (European Space Agency’s) Euclid mission and NASA’s upcoming Nancy Grace Roman Space Telescope.
      The SPHEREx mission’s all-sky survey will complement data from other NASA space telescopes. SPHEREx is illustrated second from the right. The other telescope illustrations are, from left to right: the Hubble Space Telescope, the retired Spitzer Space Telescope, the retired WISE/NEOWISE mission, the James Webb Space Telescope, and the upcoming Nancy Grace Roman Space Telescope. NASA/JPL-Caltech The IPAC archive that hosts SPHEREx data, IRSA (NASA/IPAC Infrared Science Archive), also hosts pointed observations and all-sky maps at a variety of wavelengths from previous missions. The large amount of data available through IRSA gives users a comprehensive view of the astronomical objects they want to study.
      “SPHEREx is part of the entire legacy of NASA space surveys,” said IRSA Science Lead Vandana Desai. “People are going to use the data in all kinds of ways that we can’t imagine.”
      NASA’s Office of the Chief Science Data Officer leads open science efforts for the agency. Public sharing of scientific data, tools, research, and software maximizes the impact of NASA’s science missions. To learn more about NASA’s commitment to transparency and reproducibility of scientific research, visit science.nasa.gov/open-science. To get more stories about the impact of NASA’s science data delivered directly to your inbox, sign up for the NASA Open Science newsletter.
      By Lauren Leese
      Web Content Strategist for the Office of the Chief Science Data Officer 
      More About SPHEREx
      The SPHEREx mission is managed by NASA’s Jet Propulsion Laboratory for the agency’s Astrophysics Division within the Science Mission Directorate at NASA Headquarters. BAE Systems in Boulder, Colorado, built the telescope and the spacecraft bus. The science analysis of the SPHEREx data will be conducted by a team of scientists located at 10 institutions in the U.S., two in South Korea, and one in Taiwan. Caltech in Pasadena managed and integrated the instrument. The mission’s principal investigator is based at Caltech with a joint JPL appointment. Data will be processed and archived at IPAC at Caltech. The SPHEREx dataset will be publicly available at the NASA-IPAC Infrared Science Archive. Caltech manages JPL for NASA.
      To learn more about SPHEREx, visit:
      https://nasa.gov/SPHEREx
      Media Contacts
      Calla Cofield
      Jet Propulsion Laboratory, Pasadena, Calif.
      626-808-2469
      calla.e.cofield@jpl.nasa.gov
      Amanda Adams
      Office of the Chief Science Data Officer
      256-683-6661
      amanda.m.adams@nasa.gov
      Share








      Details
      Last Updated Jul 02, 2025 Related Terms
      Open Science Astrophysics Galaxies Jet Propulsion Laboratory SPHEREx (Spectro-Photometer for the History of the Universe and Ices Explorer) The Search for Life The Universe Explore More
      3 min read Discovery Alert: Flaring Star, Toasted Planet


      Article


      4 hours ago
      11 min read 3 Years of Science: 10 Cosmic Surprises from NASA’s Webb Telescope


      Article


      5 hours ago
      7 min read A New Alloy is Enabling Ultra-Stable Structures Needed for Exoplanet Discovery


      Article


      1 day ago
      Keep Exploring Discover More Topics From NASA
      Missions



      Humans in Space



      Climate Change



      Solar System


      View the full article
    • By NASA
      Skywatching Skywatching Home What’s Up Meteor Showers Eclipses Daily Moon Guide More Tips & Guides Skywatching FAQ Night Sky Network A.M./P.M. Planet Watching, Plus the Eagle Constellation
      Mars shines in the evening, and is joined briefly by Mercury. Jupiter joins Venus as the month goes on. And all month, look for Aquila the eagle.
      Skywatching Highlights
      All Month – Planet Visibility:
      Venus: Shines brightly in the east each morning during the couple of hours before sunrise, with the Pleiades and bright stars Aldebaran and Capella. Mars: Sits in the west, about 20 degrees above the horizon as twilight fades. Sets a couple of hours after dark. Jupiter: Starts to become visible low in the east in the hour before sunrise after mid-month. You’ll notice it rises a bit higher each day through August, quickly approaching closer to Venus each morning. Mercury: Visible very low in the west (10 degrees or lower) the first week or so in July. Find it for a short time before it sets, beginning 30-45 minutes after sunset. Saturn: Rises around midnight and climbs to a point high in the south as dawn approaches. Daily Highlights:
      July 1 – 7 – Mercury is relatively bright and easy to spot without a telescope, beginning about 30-45 minutes after sunset for the first week or so of July. You will need an unobstructed view toward the horizon, and note that it sets within an hour after the Sun.
      July 21 & 22 – Moon, Venus, & Jupiter – Look toward the east this morning to find a lovely scene, with the crescent Moon and Venus, plus several bright stars. And if you have a clear view toward the horizon, Jupiter is there too, low in the sky.
      July 28 – Moon & Mars – The crescent Moon appears right next to Mars this evening after sunset.
      All month – Constellation: Aquila – The Eagle constellation, Aquila, appears in the eastern part of the sky during the first half of the night. Its brightest star, Altair, is the southernmost star in the Summer Triangle, which is an easy-to-locate star pattern in Northern Hemisphere summer skies.
      Transcript
      What’s Up for July? Mars shines in the evening sky, sixty years after its first close-up,
      July Planet Viewing
      Venus brightens your mornings, and the eagle soars overhead.
      First up, Mercury is visible for a brief time following sunset for the first week of July. Look for it very low in the west 30 to 45 minutes after sundown. It sets within the hour after that, so be on the ball if you want to catch it!
      Mars is visible for the first hour or two after it gets dark. You’ll find it sinking lower in the sky each day and looking a bit dimmer over the course of the month, as our two planets’ orbits carry them farther apart. The crescent Moon appears right next to Mars on the 28th.
      Sky chart showing Mercury and Mars in the western sky following sunset in early July. NASA/JPL-Caltech July is the 60th anniversary of the first successful flyby of Mars, by NASA’s Mariner 4 spacecraft in 1965. Mariner 4 sent back the first photos of another planet from deep space, along with the discovery that the Red Planet has only a very thin, cold atmosphere.
      Next, Saturn is rising late in the evening, and by dawn it’s high overhead to the south.
      Looking to the morning sky, Venus shines brightly all month. You’ll find it in the east during the couple of hours before sunrise, with the Pleiades and bright stars Aldebaran and Capella. And as the month goes on, Jupiter makes its morning sky debut,
      Sky chart showing Venus in the morning sky in July. NASA/JPL-Caltech rising in the hour before sunrise and appearing a little higher each day.
      By the end of the month, early risers will have the two brightest planets there greeting them each morning. They’re headed for a super-close meetup in mid-August, and the pair will be a fixture of the a.m. sky through late this year. Look for them together with the crescent moon on the 21st and 22nd.
      Aquila, The Eagle
      From July and into August, is a great time to observe the constellation Aquila, the eagle.
      Sky chart showing the shape and orientation of the constellation Aquila in the July evening sky. Aquila’s brightest star, Altair, is part of the Summer Triangle star pattern. NASA/JPL-Caltech This time of year, it soars high into the sky in the first half of the night. Aquila represents the mythical eagle that was a powerful servant and messenger of the Greek god Zeus. The eagle carried his lightning bolts and was a symbol of his power as king of the gods.
      To find Aquila in the sky, start by locating its brightest star, Altair. It’s one the three bright stars in the Summer Triangle, which is super easy to pick out during summer months in the Northern Hemisphere. Altair is the second brightest of the three, and sits at the southernmost corner of the triangle.
      The other stars in Aquila aren’t as bright as Altair, which can make observing the constellation challenging if you live in an area with a lot of light pollution. It’s easier, though, if you know how the eagle is oriented on the sky. Imagine it’s flying toward the north with its wings spread wide, its right wing pointed toward Vega. If you can find Altair, and Aquila’s next brightest star, you can usually trace out the rest of the spread-eagle shape from there. ​​The second half of July is the best time of the month to observe Aquila, as the Moon doesn’t rise until later then, making it easier to pick out the constellation’s fainter stars.
      Observing the constellation Aquila makes for a worthy challenge in the July night sky. And once you’re familiar with its shape, it’s hard not to see the mythical eagle soaring overhead among the summertime stars.
      Here are the phases of the Moon for July.
      The phases of the Moon for July 2025. NASA/JPL-Caltech You can stay up to date on all of NASA’s missions exploring the solar system and beyond at science.nasa.gov. I’m Preston Dyches from NASA’s Jet Propulsion Laboratory, and that’s What’s Up for this month.
      Keep Exploring Discover More Topics From NASA
      Missions



      Humans in Space



      Climate Change



      Solar System


      View the full article
    • By NASA
      Explore Webb Webb News Latest News Latest Images Webb’s Blog Awards X (offsite – login reqd) Instagram (offsite – login reqd) Facebook (offsite- login reqd) Youtube (offsite) Overview About Who is James Webb? Fact Sheet Impacts+Benefits FAQ Science Overview and Goals Early Universe Galaxies Over Time Star Lifecycle Other Worlds Observatory Overview Launch Deployment Orbit Mirrors Sunshield Instrument: NIRCam Instrument: MIRI Instrument: NIRSpec Instrument: FGS/NIRISS Optical Telescope Element Backplane Spacecraft Bus Instrument Module Multimedia About Webb Images Images Videos What is Webb Observing? 3d Webb in 3d Solar System Podcasts Webb Image Sonifications Webb’s First Images Team International Team People Of Webb More For the Media For Scientists For Educators For Fun/Learning Since July 2022, NASA’s James Webb Space Telescope has been unwaveringly focused on our universe. With its unprecedented power to detect and analyze otherwise invisible infrared light, Webb is making observations that were once impossible, changing our view of the cosmos from the most distant galaxies to our own solar system.
      Webb was built with the promise of revolutionizing astronomy, of rewriting the textbooks. And by any measure, it has more than lived up to the hype — exceeding expectations to a degree that scientists had not dared imagine. Since science operations began, Webb has completed more than 860 scientific programs, with one-quarter of its time dedicated to imaging and three-quarters to spectroscopy. In just three years, it has collected nearly 550 terabytes of data, yielding more than 1,600 research papers, with intriguing results too numerous to list and a host of new questions to answer.
      Here are just a few noteworthy examples.
      1. The universe evolved significantly faster than we previously thought.
      Webb was specifically designed to observe “cosmic dawn,” a time during the first billion years of the universe when the first stars and galaxies were forming. What we expected to see were a few faint galaxies, hints of what would become the galaxies we see nearby.
      Instead, Webb has revealed surprisingly bright galaxies that developed within 300 million years of the big bang; galaxies with black holes that seem far too massive for their age; and an infant Milky Way-type galaxy that existed when the universe was just 600 million years old. Webb has observed galaxies that already “turned off” and stopped forming stars within a billion years of the big bang, as well as those that developed quickly into modern-looking “grand design” spirals within 1.5 billion years.
      Hundreds of millions of years might not seem quick for a growth spurt, but keep in mind that the universe formed in the big bang roughly 13.8 billion years ago. If you were to cram all of cosmic time into one year, the most distant of these galaxies would have matured within the first couple of weeks, rapidly forming multiple generations of stars and enriching the universe with the elements we see today.
      Image: JADES deep field
      A near-infrared image from NASA’s James Webb Space Telescope shows a region known as the JADES Deep Field. Tens of thousands of galaxies are visible in this tiny patch of sky, including Little Red Dots and hundreds of galaxies that existed more than 13.2 billion years ago, when the universe was less than 600 million years old. Webb also spotted roughly 80 ancient supernovae, many of which exploded when the universe was less than 2 billion years old. This is ten times more supernovae than had ever been discovered before in the early universe. Comparing these supernovae from the distant past with those in the more recent, nearby universe helps us understand how stars in these early times formed, lived, and died, seeding space with the elements for new generations of stars and their planets. NASA, ESA, CSA, STScI, JADES Collaboration 2. Deep space is scattered with enigmatic “Little Red Dots.”
      Webb has revealed a new type of galaxy: a distant population of mysteriously compact, bright, red galaxies dubbed Little Red Dots. What makes Little Red Dots so bright and so red? Are they lit up by dense groupings of unusually bright stars or by gas spiraling into a supermassive black hole, or both? And whatever happened to them? Little Red Dots seem to have appeared in the universe around 600 million years after the big bang (13.2 billion years ago), and rapidly declined in number less than a billion years later. Did they evolve into something else? If so, how? Webb is probing Little Red Dots in more detail to answer these questions.
      3. Pulsating stars and a triply lensed supernova are further evidence that the “Hubble Tension” is real.
      How fast is the universe expanding? It’s hard to say because different ways of calculating the current expansion rate yield different results — a dilemma known as the Hubble Tension. Are these differences just a result of measurement errors, or is there something weird going on in the universe? So far, Webb data indicates that the Hubble Tension is not caused by measurement errors. Webb was able to distinguish pulsating stars from nearby stars in a crowded field, ensuring that the measurements weren’t contaminated by extra light. Webb also discovered a distant, gravitationally lensed supernova whose image appears in three different locations and at three different times during its explosion. Calculating the expansion rate based on the brightness of the supernova at these three different times provides an independent check on measurements made using other techniques. Until the matter of the Hubble Tension is settled, Webb will continue measuring different objects and exploring new methods.
      4. Webb has found surprisingly rich and varied atmospheres on gas giants orbiting distant stars.
      While NASA’s Hubble Space Telescope made the first detection of gases in the atmosphere of a gas giant exoplanet (a planet outside our solar system), Webb has taken studies to an entirely new level. Webb has revealed a rich cocktail of chemicals, including hydrogen sulfide, ammonia, carbon dioxide, methane, and sulfur dioxide — none of which had been clearly detected in an atmosphere outside our solar system before. Webb has also been able to examine exotic climates of gas giants as never before, detecting flakes of silica “snow” in the skies of the puffy, searing-hot gas giant WASP-17 b, for example, and measuring differences in temperature and cloud cover between the permanent morning and evening skies of WASP-39 b.
      Image: Spectrum of WASP-107 b
      A transmission spectrum of the “warm Neptune” exoplanet WASP-107 b captured by NASA’s Hubble and Webb space telescopes, shows clear evidence for water, carbon dioxide, carbon monoxide, methane, sulfur dioxide, and ammonia in the planet’s atmosphere. These measurements allowed researchers to estimate the interior temperature and mass of the core of the planet, as well as understand the chemistry and dynamics of the atmosphere. NASA, ESA, CSA, Ralf Crawford (STScI) 5. A rocky planet 40 light-years from Earth may have an atmosphere fed by gas bubbling up from its lava-covered surface.
      Detecting, let alone analyzing, a thin layer of gas surrounding a small rocky planet is no easy feat, but Webb’s extraordinary ability to measure extremely subtle changes in the brightness of infrared light makes it possible. So far, Webb has been able to rule out significant atmosphere on a number of rocky planets, and has found tantalizing signs of carbon monoxide or carbon dioxide on 55 Cancri e, a lava world that orbits a Sun-like star. With findings like these, Webb is laying the groundwork for NASA’s future Habitable Worlds Observatory, which will be the first mission purpose-built to directly image and search for life on Earth-like planets around Sun-like stars.
      6. Webb exposes the skeletal structure of nearby spiral galaxies in mesmerizing detail.
      We already knew that galaxies are collections of stars, planets, dust, gas, dark matter, and black holes: cosmic cities where stars form, live, die, and are recycled into the next generation. But we had never been able to see the structure of a galaxy and the interactions between stars and their environment in such detail. Webb’s infrared vision reveals filaments of dust that trace the spiral arms, old star clusters that make up galactic cores, newly forming stars still encased in dense cocoons of glowing dust and gas, and clusters of hot young stars carving enormous cavities in the dust. It also elucidates how stellar winds and explosions actively reshape their galactic homes.
      Image: PHANGS Phantom Galaxy (M74/NGC 628)
      A near- to mid-infrared image from NASA’s James Webb Space Telescope highlights details in the complex structure of a nearby galaxy that are invisible to other telescopes. The image of NGC 628, also known as the Phantom Galaxy, shows spiral arms with lanes of warm dust (represented in red), knots of glowing gas (orange-yellow), and giant bubbles (black) carved by hot, young stars. The dust-free core of the galaxy is filled with older, cooler stars (blue). NASA, ESA, CSA, STScI, Janice Lee (STScI), Thomas Williams (Oxford), PHANGS team 7. It can be hard to tell the difference between a brown dwarf and a rogue planet.
      Brown dwarfs form like stars, but are not dense or hot enough to fuse hydrogen in their cores like stars do. Rogue planets form like other planets, but have been ejected from their system and no longer orbit a star. Webb has spotted hundreds of brown-dwarf-like objects in the Milky Way, and has even detected some candidates in a neighboring galaxy. But some of these objects are so small — just a few times the mass of Jupiter — that it is hard to figure out how they formed. Are they free-floating gas giant planets instead? What is the least amount of material needed to form a brown dwarf or a star? We’re not sure yet, but thanks to three years of Webb observations, we now know there is a continuum of objects from planets to brown dwarfs to stars.
      8. Some planets might be able to survive the death of their star.
      When a star like our Sun dies, it swells up to form a red giant large enough to engulf nearby planets. It then sheds its outer layers, leaving behind a super-hot core known as a white dwarf. Is there a safe distance that planets can survive this process? Webb might have found some planets orbiting white dwarfs. If these candidates are confirmed, it would mean that it is possible for planets to survive the death of their star, remaining in orbit around the slowly cooling stellar ember.
      9. Saturn’s water supply is fed by a giant fountain of vapor spewing from Enceladus.
      Among the icy “ocean worlds” of our solar system, Saturn’s moon Enceladus might be the most intriguing. NASA’s Cassini mission first detected water plumes coming out of its southern pole. But only Webb could reveal the plume’s true scale as a vast cloud spanning more than 6,000 miles, about 20 times wider than Enceladus itself. This water spreads out into a donut-shaped torus encircling Saturn beyond the rings that are visible in backyard telescopes. While a fraction of the water stays in that ring, the majority of it spreads throughout the Saturnian system, even raining down onto the planet itself. Webb’s unique observations of rings, auroras, clouds, winds, ices, gases, and other materials and phenomena in the solar system are helping us better understand what our cosmic neighborhood is made of and how it has changed over time.
      Video: Water plume and torus from Enceladus
      A combination of images and spectra captured by NASA’s James Webb Space Telescope show a giant plume of water jetting out from the south pole of Saturn’s moon Enceladus, creating a donut-shaped ring of water around the planet.
      Credit: NASA, ESA, CSA, G. Villanueva (NASA’s Goddard Space Flight Center), A. Pagan (STScI), L. Hustak (STScI) 10. Webb can size up asteroids that may be headed for Earth.
      In 2024 astronomers discovered an asteroid that, based on preliminary calculations, had a chance of hitting Earth. Such potentially hazardous asteroids become an immediate focus of attention, and Webb was uniquely able to measure the object, which turned out to be the size of a 15-story building. While this particular asteroid is no longer considered a threat to Earth, the study demonstrated Webb’s ability to assess the hazard.
      Webb also provided support for NASA’s Double Asteroid Redirection Test (DART) mission, which deliberately smashed into the Didymos binary asteroid system, showing that a planned impact could deflect an asteroid on a collision course with Earth. Both Webb and Hubble observed the impact, serving witness to the resulting spray of material that was ejected. Webb’s spectroscopic observations of the system confirmed that the composition of the asteroids is probably typical of those that could threaten Earth.
      —-
      In just three years of operations, Webb has brought the distant universe into focus, revealing unexpectedly bright and numerous galaxies. It has unveiled new stars in their dusty cocoons, remains of exploded stars, and skeletons of entire galaxies. It has studied weather on gas giants, and hunted for atmospheres on rocky planets. And it has provided new insights into the residents of our own solar system.
      But this is only the beginning. Engineers estimate that Webb has enough fuel to continue observing for at least 20 more years, giving us the opportunity to answer additional questions, pursue new mysteries, and put together more pieces of the cosmic puzzle.
      For example: What were the very first stars like? Did stars form differently in the early universe? Do we even know how galaxies form? How do stars, dust, and supermassive black holes affect each other? What can merging galaxy clusters tell us about the nature of dark matter? How do collisions, bursts of stellar radiation, and migration of icy pebbles affect planet-forming disks? Can atmospheres survive on rocky worlds orbiting active red dwarf stars? Is Uranus’s moon Ariel an ocean world?
      As with any scientific endeavor, every answer raises more questions, and Webb has shown that its investigative power is unmatched. Demand for observing time on Webb is at an all-time high, greater than any other telescope in history, on the ground or in space. What new findings await?
      By Dr. Macarena Garcia Marin and Margaret W. Carruthers, Space Telescope Science Institute, Baltimore, Maryland
      Media Contacts
      Laura Betz – laura.e.betz@nasa.gov
      NASA’s Goddard Space Flight Center, Greenbelt, Md.
      Christine Pulliam – cpulliam@stsci.edu
      Space Telescope Science Institute, Baltimore, Md.
      Related Information
      More Webb News
      More Webb Images
      Webb Science Themes
      Webb Mission Page
      Related For Kids
      What is the Webb Telescope?
      SpacePlace for Kids
      En Español
      Ciencia de la NASA
      NASA en español 
      Space Place para niños
      Keep Exploring Related Topics
      James Webb Space Telescope


      Webb is the premier observatory of the next decade, serving thousands of astronomers worldwide. It studies every phase in the…


      Galaxies



      Exoplanets



      Universe


      Share








      Details
      Last Updated Jul 02, 2025 Editor Marty McCoy Contact Laura Betz laura.e.betz@nasa.gov Related Terms
      James Webb Space Telescope (JWST) Astrophysics Black Holes Brown Dwarfs Exoplanet Science Exoplanets Galaxies Galaxies, Stars, & Black Holes Goddard Space Flight Center Nebulae Science & Research Star-forming Nebulae Stars Studying Exoplanets The Universe View the full article
  • Check out these Videos

×
×
  • Create New...