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By NASA
5 Min Read Making Mars’ Moons: Supercomputers Offer ‘Disruptive’ New Explanation
A NASA study using a series of supercomputer simulations reveals a potential new solution to a longstanding Martian mystery: How did Mars get its moons? The first step, the findings say, may have involved the destruction of an asteroid.
The research team, led by Jacob Kegerreis, a postdoctoral research scientist at NASA’s Ames Research Center in California’s Silicon Valley, found that an asteroid passing near Mars could have been disrupted – a nice way of saying “ripped apart” – by the Red Planet’s strong gravitational pull.
The team’s simulations show the resulting rocky fragments being strewn into a variety of orbits around Mars. More than half the fragments would have escaped the Mars system, but others would’ve stayed in orbit. Tugged by the gravity of both Mars and the Sun, in the simulations some of the remaining asteroid pieces are set on paths to collide with one another, every encounter further grinding them down and spreading more debris.
Many collisions later, smaller chunks and debris from the former asteroid could have settled into a disk encircling the planet. Over time, some of this material is likely to have clumped together, possibly forming Mars’ two small moons, Phobos and Deimos.
To assess whether this was a realistic chain of events, the research team explored hundreds of different close encounter simulations, varying the asteroid’s size, spin, speed, and distance at its closest approach to the planet. The team used their high-performance, open-source computing code, called SWIFT, and the advanced computing systems at Durham University in the United Kingdom to study in detail both the initial disruption and, using another code, the subsequent orbits of the debris.
In a paper published Nov. 20 in the journal Icarus, the researchers report that, in many of the scenarios, enough asteroid fragments survive and collide in orbit to serve as raw material to form the moons.
“It’s exciting to explore a new option for the making of Phobos and Deimos – the only moons in our solar system that orbit a rocky planet besides Earth’s,” said Kegerreis. “Furthermore, this new model makes different predictions about the moons’ properties that can be tested against the standard ideas for this key event in Mars’ history.”
Two hypotheses for the formation of the Martian moons have led the pack. One proposes that passing asteroids were captured whole by Mars’ gravity, which could explain the moons’ somewhat asteroid-like appearance. The other says that a giant impact on the planet blasted out enough material – a mix of Mars and impactor debris – to form a disk and, ultimately, the moons. Scientists believe a similar process formed Earth’s Moon.
The latter explanation better accounts for the paths the moons travel today – in near-circular orbits that closely align with Mars’ equator. However, a giant impact ejects material into a disk that, mostly, stays close to the planet. And Mars’ moons, especially Deimos, sit quite far away from the planet and probably formed out there, too.
“Our idea allows for a more efficient distribution of moon-making material to the outer regions of the disk,” said Jack Lissauer, a research scientist at Ames and co-author on the paper. “That means a much smaller ‘parent’ asteroid could still deliver enough material to send the moons’ building blocks to the right place.”
It’s exciting to explore a new option for the making of Phobos and Deimos – the only moons in our solar system that orbit a rocky planet besides Earth’s.
Jacob Kegerreis
Postdoctoral research scientist at NASA’s Ames Research Center
Testing different ideas for the formation of Mars’ moons is the primary goal of the upcoming Martian Moons eXploration (MMX) sample return mission led by JAXA (Japan Aerospace Exploration Agency). The spacecraft will survey both moons to determine their origin and collect samples of Phobos to bring to Earth for study. A NASA instrument on board, called MEGANE – short for Mars-moon Exploration with GAmma rays and Neutrons – will identify the chemical elements Phobos is made of and help select sites for the sample collection. Some of the samples will be collected by a pneumatic sampler also provided by NASA as a technology demonstration contribution to the mission. Understanding what the moons are made of is one clue that could help distinguish between the moons having an asteroid origin or a planet-plus-impactor source.
Before scientists can get their hands on a piece of Phobos to analyze, Kegerreis and his team will pick up where they left off demonstrating the formation of a disk that has enough material to make Phobos and Deimos.
“Next, we hope to build on this proof-of-concept project to simulate and study in greater detail the full timeline of formation,” said Vincent Eke, associate professor at the Institute for Computational Cosmology at Durham University and a co-author on the paper. “This will allow us to examine the structure of the disk itself and make more detailed predictions for what the MMX mission could find.”
For Kegerreis, this work is exciting because it also expands our understanding of how moons might be born – even if it turns out that Mars’ own formed by a different route. The simulations offer a fascinating exploration, he says, of the possible outcomes of encounters between objects like asteroids and planets. These events were common in the early solar system, and simulations could help researchers reconstruct the story of how our cosmic backyard evolved.
This research is a collaborative effort between Ames and Durham University, supported by the Institute for Computational Cosmology’s Planetary Giant Impact Research group. The simulations used were run using the open-source SWIFT code, carried out on the DiRAC (Distributed Research Utilizing Advanced Computing) Memory Intensive service (“COSMA”), hosted by Durham University on behalf of the DiRAC High-Performance Computing facility.
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Members of the news media interested in covering this topic should reach out to the NASA Ames newsroom.
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Last Updated Nov 20, 2024 Related Terms
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Zoom into Solar Orbiter's four new Sun images, assembled from high-resolution observations by the spacecraft's PHI and EUI instruments made on 22 March 2023. The PHI images are the highest-resolution full views of the Sun's visible surface to date, including maps of the Sun's messy magnetic field and movement on the surface. These can be compared to the new EUI image, which reveals the Sun's glowing outer atmosphere, or corona.
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By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Abigail Reigner, a systems engineer at NASA’s Glenn Research Center in Cleveland, supports the agency’s research in electrified aircraft propulsion to enable more sustainable air travel. Behind her is a 25% scale model of NASA’s SUbsonic Single Aft eNgine (SUSAN) Electrofan aircraft concept used to test and demonstrate hybrid electric propulsion systems for emission reductions and performance boosts in future commercial aircraft.
Credit: NASA/Sara Lowthian-Hanna Growing up outside of Philadelphia, Abigail Reigner spent most of her childhood miles away from where her family called home, and where there was little trace of her Native American tribe and culture.
Belonging to the Comanche Nation that resides in Lawton, Oklahoma, Reigner’s parents made every effort to keep her connected to her Indigenous heritage and part of a community that would later play a key role in her professional journey.
“My parents were really adamant on making sure my brother and I were still involved in the Native American traditions."
Abigail Reigner
“My parents were really adamant on making sure my brother and I were still involved in the Native American traditions,” Reigner said. “We would go down to Oklahoma often in the summertime, spending time with family and staying immersed in our culture.”
Both her parents come from a teaching background, so Reigner was surrounded by hands-on learning experiences early in life. As a school teacher, her mother would participate in local outreach events each year, talking and interacting with students. Her father, a middle school technology education teacher, taught Reigner how to use computer-aided design (CAD) and helped introduce her to the world of engineering at a young age.
These unique experiences helped spark Reigner’s curiosity for learning about science, technology, engineering, and math (STEM) and connecting with others in her community who shared these interests. Reigner says she never takes her upbringing for granted.
“I feel pretty lucky to have grown up with so many educational opportunities, and I try to use them as a way to give back to my community,” Reigner said.
After participating in various engineering and robotics classes in high school and realizing a career in STEM was the right fit for her, Reigner went on to attend the Rochester Institute of Technology in New York where she earned bachelor’s and master’s degrees in mechanical engineering.
During her time there, she joined the American Indian Science and Engineering Society (AISES) where she got the unique opportunity to connect with other Indigenous students and mentors in STEM fields and gain leadership experience on projects that eventually set her up for internship opportunities at NASA.
“The opportunities I got through AISES led me to get an internship at NASA’s Jet Propulsion Laboratory during the summer of 2021, and then an eight-month co-op the following year working in the center’s materials science division,” Reigner said.
Through AISES, Reigner also met Joseph Connolly, an aerospace engineer at NASA’s Glenn Research Center in Cleveland who was looking to recruit Indigenous students for full-time positions in the agency. Upon graduating from college, Reigner joined NASA Glenn as an engineer in the summer of 2024.
Abigail Reigner (top far left) and Joseph Connolly (middle far right) pose with NASA employees while staffing a booth at an American Indian Science and Engineering Society (AISES) conference to help recruit Indigenous students to the agency. Credit: Abigail Reigner Today, Reigner works as a systems engineer supporting NASA Glenn’s efforts to test and demonstrate electrified aircraft propulsion technologies for future commercial aircraft as part of the agency’s mission to make air travel more sustainable.
One of the projects she works on is NASA’s Electrified Powertrain Flight Demonstration (EPFD), where she supports risk-reduction testing that enables the project to explore the feasibility of hybrid electric propulsion in reducing emissions and improving efficiency in future aircraft.
“It’s always good to know that you’re doing something that is furthering the benefit of humanity,” Reigner said. “Seeing that unity across NASA centers and knowing that you are a part of something that is accelerating technology for the future is very cool.”
“I really feel like the reason I am here at NASA is because of the success of not just the Native American support group here at Glenn, but also Natives across the agency.”
Abigail Reigner
The growing community of Native Americans at NASA Glenn has fostered several initiatives over the years that have helped recruit, inspire, and retain Indigenous employees.
Leveraging some of the agency’s diversity programs that provide educational STEM opportunities for underrepresented communities, the Native Americans at NASA group has encouraged more students with Indigenous backgrounds to get involved in technical projects while developing the skills needed to excel in STEM fields.
“The Native American support group at NASA has been around since the mid-to-late 1980s and was actually one of the first Native American employee resources groups at the agency,” Connolly said. “Through this, we’ve been able to connect a number of Native employees with senior leaders across NASA and establish more agencywide recruitment efforts and initiatives for Native Americans.”
These initiatives range from support through NASA’s Minority University Research and Education Project (MUREP) to help recruit more Indigenous students, to encouraging participation in hands-on learning experiences through projects such as NASA’s University Leadership Initiative (ULI) and the agency’s involvement in the First Nations Launch competition, which helps provide students with opportunities to conduct research while developing engineering and team-building skills.
The efforts of the Native American community at NASA Glenn and across the agency have been successful in not only creating a direct pipeline for Indigenous students into the NASA workforce, but also allowing them to feel seen and represented in the agency, says Connolly.
For Reigner, having this community and resource group at NASA to help guide and support her through her journey has been crucial to her success and important for the future of diversity within the agency.
“I really feel like the reason I am here at NASA is because of the success of not just the Native American support group here at Glenn, but also Natives across the agency,” Reigner said. Without their support and initiatives to recruit and retain students, I wouldn’t be here today.”
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By NASA
Clayton P. Turner, associate administrator for Space Technology Mission DirectorateCredit: NASA Clayton P. Turner will serve as the associate administrator of the Space Technology Mission Directorate (STMD) at the agency’s headquarters in Washington, NASA Administrator Bill Nelson announced Monday. His appointment is effective immediately.
Turner has served as the acting associate administrator of STMD since July. In this role, Turner will continue to oversee executive leadership, strategic planning, and overall management of all technology maturation and demonstration programs executed from the directorate enabling critical space focused technologies that deliver today and help create tomorrow.
“Under Turner’s skilled and steady hand, the Space Technology Mission Directorate will continue to do what it does best: help NASA push the boundaries of what’s possible and drive American leadership in space,” said NASA Administrator Bill Nelson. “I look forward to what STMD will achieve under Turner’s direction.”
As NASA embarks on the next era of space exploration, STMD leverages partnerships to advance technologies and test new capabilities helping the agency develop a sustainable presence on the Moon and beyond. As associate administrator of STMD, Turner will plan, coordinate, and evaluate the mission directorate’s full range of programs and activities, including budget formulation and execution, as well as represent the programs to officials within and outside the agency.
Previously, Turner served as NASA Langley Research Center Director since September 2019 and has been with the agency for more than 30 years. He has held several roles at NASA Langley, including engineering director, associate center director, and deputy center director. Throughout his NASA career, he has worked on many projects for the agency, including: the Earth Science Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation Project; the materials technology development Gas Permeable Polymer Materials Project; the Space Shuttle Program’s Return to Flight work; the flight test of the Ares 1-X rocket; the flight test of the Orion Launch Abort System; and the entry, descent, and landing segment of the Mars Science Laboratory.
In recognition of his commitment to the agency and engineering, Turner has received many prestigious awards, such as the NASA Distinguished Service Medal, the NASA Outstanding Leadership Medal, the NASA Exceptional Engineering Achievement Medal. He is also an Associate Fellow of the American Institute of Aeronautics and Astronautics (AIAA) and a Board of Trustees member of his alma mater, Rochester Institute of Technology.
NASA Glenn Research Center Deputy Director, Dawn Schaible, became acting Langley Center Director in July and will continue to serve in this role. At NASA Langley, Schaible leads a skilled group of more than 3,000 civil servant and contractor scientists, researchers, engineers, and support staff, who work to advance aviation, expand understanding of Earth’s atmosphere, and develop technology for space exploration.
For more about Turner’s experience, visit his full biography online at:
https://go.nasa.gov/48UmkmS
-end-
Meira Bernstein / Jasmine Hopkins
Headquarters, Washington
202-358-1600
meira.b.bernstein@nasa.gov / jasmine.s.hopkins@nasa.gov
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Last Updated Nov 18, 2024 LocationNASA Headquarters Related Terms
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By NASA
Hubble Space Telescope Home NASA’s Hubble Sees… Hubble Space Telescope 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 Explore the Night Sky Observatory Hubble Observatory Hubble Design Mission Operations Missions to Hubble Hubble vs Webb Team Hubble Team Career Aspirations Hubble Astronauts News Hubble News Hubble News Archive Social Media Media Resources Multimedia Multimedia Images Videos Sonifications Podcasts E-books Lithographs Fact Sheets Glossary Posters Hubble on the NASA App More Online Activities 5 Min Read NASA’s Hubble Sees Aftermath of Galaxy’s Scrape with Milky Way
This artist’s concept shows a closeup of the Large Magellanic Cloud, a dwarf galaxy that is one of the Milky Way galaxy’s nearest neighbors. Credits:
NASA, ESA, Ralf Crawford (STScI) A story of survival is unfolding at the outer reaches of our galaxy, and NASA’s Hubble Space Telescope is witnessing the saga.
The Large Magellanic Cloud, also called the LMC, is one of the Milky Way galaxy’s nearest neighbors. This dwarf galaxy looms large on the southern nighttime sky at 20 times the apparent diameter of the full Moon.
Many researchers theorize that the LMC is not in orbit around our galaxy, but is just passing by. These scientists think that the LMC has just completed its closest approach to the much more massive Milky Way. This passage has blown away most of the spherical halo of gas that surrounds the LMC.
Now, for the first time, astronomers been able to measure the size of the LMC’s halo – something they could do only with Hubble. In a new study to be published in The Astrophysical Journal Letters, researchers were surprised to find that it is so extremely small, about 50,000 light-years across. That’s around 10 times smaller than halos of other galaxies that are the LMC’s mass. Its compactness tells the story of its encounter with the Milky Way.
“The LMC is a survivor,” said Andrew Fox of AURA/STScI for the European Space Agency in Baltimore, who was principal investigator on the observations. “Even though it’s lost a lot of its gas, it’s got enough left to keep forming new stars. So new star-forming regions can still be created. A smaller galaxy wouldn’t have lasted – there would be no gas left, just a collection of aging red stars.”
This artist’s concept shows the Large Magellanic Cloud, or LMC, in the foreground as it passes through the gaseous halo of the much more massive Milky Way galaxy. The encounter has blown away most of the spherical halo of gas that surrounds the LMC, as illustrated by the trailing gas stream reminiscent of a comet’s tail. Still, a compact halo remains, and scientists do not expect this residual halo to be lost. The team surveyed the halo by using the background light of 28 quasars, an exceptionally bright type of active galactic nucleus that shines across the universe like a lighthouse beacon. Their light allows scientists to “see” the intervening halo gas indirectly through the absorption of the background light. The lines represent the Hubble Space Telescope’s view from its orbit around Earth to the distant quasars through the LMC’s gas. NASA, ESA, Ralf Crawford (STScI)
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Though quite a bit worse for wear, the LMC still retains a compact, stubby halo of gas – something that it wouldn’t have been able to hold onto gravitationally had it been less massive. The LMC is 10 percent the mass of the Milky Way, making it heftier than most dwarf galaxies.
“Because of the Milky Way’s own giant halo, the LMC’s gas is getting truncated, or quenched,” explained STScI’s Sapna Mishra, the lead author on the paper chronicling this discovery. “But even with this catastrophic interaction with the Milky Way, the LMC is able to retain 10 percent of its halo because of its high mass.”
A Gigantic Hair Dryer
Most of the LMC’s halo was blown away due to a phenomenon called ram-pressure stripping. The dense environment of the Milky Way pushes back against the incoming LMC and creates a wake of gas trailing the dwarf galaxy – like the tail of a comet.
“I like to think of the Milky Way as this giant hairdryer, and it’s blowing gas off the LMC as it comes into us,” said Fox. “The Milky Way is pushing back so forcefully that the ram pressure has stripped off most of the original mass of the LMC’s halo. There’s only a little bit left, and it’s this small, compact leftover that we’re seeing now.”
As the ram pressure pushes away much of the LMC’s halo, the gas slows down and eventually will rain into the Milky Way. But because the LMC has just gotten past its closest approach to the Milky Way and is moving outward into deep space again, scientists do not expect the whole halo will be lost.
Only with Hubble
To conduct this study, the research team analyzed ultraviolet observations from the Mikulski Archive for Space Telescopes at STScI. Most ultraviolet light is blocked by the Earth’s atmosphere, so it cannot be observed with ground-based telescopes. Hubble is the only current space telescope tuned to detect these wavelengths of light, so this study was only possible with Hubble.
The team surveyed the halo by using the background light of 28 bright quasars. The brightest type of active galactic nucleus, quasars are believed to be powered by supermassive black holes. Shining like lighthouse beacons, they allow scientists to “see” the intervening halo gas indirectly through the absorption of the background light. Quasars reside throughout the universe at extreme distances from our galaxy.
This artist’s concept illustrates the Large Magellanic Cloud’s (LMC’s) encounter with the Milky Way galaxy’s gaseous halo. In the top panel, at the middle of the right side, the LMC begins crashing through our galaxy’s much more massive halo. The bright purple bow shock represents the leading edge of the LMC’s halo, which is being compressed as the Milky Way’s halo pushes back against the incoming LMC. In the middle panel, part of the halo is being stripped and blown back into a streaming tail of gas that eventually will rain into the Milky Way. The bottom panel shows the progression of this interaction, as the LMC’s comet-like tail becomes more defined. A compact LMC halo remains. Because the LMC is just past its closest approach to the Milky Way and is moving outward into deep space again, scientists do not expect the residual halo will be lost. NASA, ESA, Ralf Crawford (STScI)
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The scientists used data from Hubble’s Cosmic Origins Spectrograph (COS) to detect the presence of the halo’s gas by the way it absorbs certain colors of light from background quasars. A spectrograph breaks light into its component wavelengths to reveal clues to the object’s state, temperature, speed, quantity, distance, and composition. With COS, they measured the velocity of the gas around the LMC, which allowed them to determine the size of the halo.
Because of its mass and proximity to the Milky Way, the LMC is a unique astrophysics laboratory. Seeing the LMC’s interplay with our galaxy helps scientists understand what happened in the early universe, when galaxies were closer together. It also shows just how messy and complicated the process of galaxy interaction is.
Looking to the Future
The team will next study the front side of the LMC’s halo, an area that has not yet been explored.
“In this new program, we are going to probe five sightlines in the region where the LMC’s halo and the Milky Way’s halo are colliding,” said co-author Scott Lucchini of the Center for Astrophysics | Harvard & Smithsonian. “This is the location where the halos are compressed, like two balloons pushing against each other.”
The Hubble Space Telescope has been operating for over 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, Colorado, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, Maryland, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.
Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Media Contacts:
Claire Andreoli (claire.andreoli@nasa.gov)
NASA’s Goddard Space Flight Center, Greenbelt, MD
Ann Jenkins, Ray Villard
Space Telescope Science Institute, Baltimore, MD
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Last Updated Nov 14, 2024 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
Astrophysics Astrophysics Division Galaxies Hubble Space Telescope Irregular Galaxies Spiral Galaxies The Milky Way Keep Exploring Discover More Topics From NASA
Hubble Space Telescope
Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.
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Hubble’s Galaxies
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