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By NASA
NASA’s Dawn spacecraft captured this image of Vesta as it left the giant asteroid’s orbit in 2012. The framing camera was looking down at the north pole, which is in the middle of the image.NASA/JPL-Caltech/UCLA/MPS/DLR/IDA Known as flow formations, these channels could be etched on bodies that would seem inhospitable to liquid because they are exposed to the extreme vacuum conditions of space.
Pocked with craters, the surfaces of many celestial bodies in our solar system provide clear evidence of a 4.6-billion-year battering by meteoroids and other space debris. But on some worlds, including the giant asteroid Vesta that NASA’s Dawn mission explored, the surfaces also contain deep channels, or gullies, whose origins are not fully understood.
A prime hypothesis holds that they formed from dry debris flows driven by geophysical processes, such as meteoroid impacts, and changes in temperature due to Sun exposure. A recent NASA-funded study, however, provides some evidence that impacts on Vesta may have triggered a less-obvious geologic process: sudden and brief flows of water that carved gullies and deposited fans of sediment. By using lab equipment to mimic conditions on Vesta, the study, which appeared in Planetary Science Journal, detailed for the first time what the liquid could be made of and how long it would flow before freezing.
Although the existence of frozen brine deposits on Vesta is unconfirmed, scientists have previously hypothesized that meteoroid impacts could have exposed and melted ice that lay under the surface of worlds like Vesta. In that scenario, flows resulting from this process could have etched gullies and other surface features that resemble those on Earth.
To explore potential explanations for deep channels, or gullies, seen on Vesta, scientists used JPL’s Dirty Under-vacuum Simulation Testbed for Icy Environments, or DUSTIE, to simulate conditions on the giant asteroid that would occur after meteoroids strike the surface.NASA/JPL-Caltech But how could airless worlds — celestial bodies without atmospheres and exposed to the intense vacuum of space — host liquids on the surface long enough for them to flow? Such a process would run contrary to the understanding that liquids quickly destabilize in a vacuum, changing to a gas when the pressure drops.
“Not only do impacts trigger a flow of liquid on the surface, the liquids are active long enough to create specific surface features,” said project leader and planetary scientist Jennifer Scully of NASA’s Jet Propulsion Laboratory in Southern California, where the experiments were conducted. “But for how long? Most liquids become unstable quickly on these airless bodies, where the vacuum of space is unyielding.”
The critical component turns out to be sodium chloride — table salt. The experiments found that in conditions like those on Vesta, pure water froze almost instantly, while briny liquids stayed fluid for at least an hour. “That’s long enough to form the flow-associated features identified on Vesta, which were estimated to require up to a half-hour,” said lead author Michael J. Poston of the Southwest Research Institute in San Antonio.
Launched in 2007, the Dawn spacecraft traveled to the main asteroid belt between Mars and Jupiter to orbit Vesta for 14 months and Ceres for almost four years. Before ending in 2018, the mission uncovered evidence that Ceres had been home to a subsurface reservoir of brine and may still be transferring brines from its interior to the surface. The recent research offers insights into processes on Ceres but focuses on Vesta, where ice and salts may produce briny liquid when heated by an impact, scientists said.
Re-creating Vesta
To re-create Vesta-like conditions that would occur after a meteoroid impact, the scientists relied on a test chamber at JPL called the Dirty Under-vacuum Simulation Testbed for Icy Environments, or DUSTIE. By rapidly reducing the air pressure surrounding samples of liquid, they mimicked the environment around fluid that comes to the surface. Exposed to vacuum conditions, pure water froze instantly. But salty fluids hung around longer, continuing to flow before freezing.
The brines they experimented with were a little over an inch (a few centimeters) deep; scientists concluded the flows on Vesta that are yards to tens of yards deep would take even longer to refreeze.
The researchers were also able to re-create the “lids” of frozen material thought to form on brines. Essentially a frozen top layer, the lids stabilize the liquid beneath them, protecting it from being exposed to the vacuum of space — or, in this case the vacuum of the DUSTIE chamber — and helping the liquid flow longer before freezing again.
This phenomenon is similar to how on Earth lava flows farther in lava tubes than when exposed to cool surface temperatures. It also matches up with modeling research conducted around potential mud volcanoes on Mars and volcanoes that may have spewed icy material from volcanoes on Jupiter’s moon Europa.
“Our results contribute to a growing body of work that uses lab experiments to understand how long liquids last on a variety of worlds,” Scully said.
Find more information about NASA’s Dawn mission here:
https://science.nasa.gov/mission/dawn/
News Media Contacts
Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, Calif.
818-287-4115
gretchen.p.mccartney@jpl.nasa.gov
Karen Fox / Molly Wasser
NASA Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
2024-178
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Last Updated Dec 20, 2024 Related Terms
Dawn Asteroids Ceres Jet Propulsion Laboratory Vesta Explore More
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By NASA
On Nov. 6, 2024, NASA Night brought cosmic excitement to the Toyota Center, where Johnson Space Center employees joined 16,208 fans who interacted with NASA as they watched the Houston Rockets claim victory over the San Antonio Spurs.
Energy soared as International Space Station Program Manager Dana Weigel stepped up to take the first shot.
International Space Station Program Manager Dana Weigel takes the first shot on Nov. 6, 2024, as the Houston Rockets go up against the San Antonio Spurs at Toyota Center.NASA/Helen Arase Vargas The ceremonial first shot also gave back to the community, with Rockets owner Tilman Fertitta donating $1,000 to the Clutch City Foundation to support underserved youth through education, sports, and disaster relief.
Throughout the game, Johnson employees kept the crowd engaged with NASA trivia, creating a “launch countdown” energy that had fans cheering. The arena lit up as Adam Savage narrated a video showcasing the International Space Station’s groundbreaking contributions to science. From unlocking discoveries impossible on Earth to testing critical technologies for our return to the Moon, the orbiting laboratory plays a vital role in advancing medical and social breakthroughs that enhance life on our planet.
The Artemis II crew also appeared on the jumbotron, reminding everyone of NASA’s mission to establish a long-term presence on the Moon for scientific discovery, economic benefits, and to inspire a new generation of explorers.
Dana Weigel, center, shows off a Rockets jersey on the court with Rockets mascot Clutch, left, and NASA mascot Cosmo.NASA/Helen Arase Vargas In the Sky Court area of the stadium concourse, Johnson volunteers held “mission control” with an interactive exhibit that drew fans in like a gravitational pull. From exploring a Space Launch System model and handling a spacesuit helmet and glove to touching a 3.4-billion-year-old Moon rock collected during Apollo 17, NASA’s booth offered attendees a glimpse into space exploration.
Visitors had the chance to ask questions and bring home mission pins, stickers, and hands-on activities, provided by the International Space Station Program and the Artemis campaign. Seventy-five “Lucky Row” fans also received bags filled with NASA outreach materials, courtesy of the Johnson Public Engagement team.
NASA’s Johnson Space Center volunteers connect with fans at the game through an interactive exhibit.NASA The Orion Flight Simulator, with its realistic switches and displays, provided an immersive experience that allowed fans to dock the Orion spacecraft to humanity’s first lunar space station, Gateway.
More than 600 fans eagerly lined up to experience NASA’s mobile exhibit trailer in the Toyota Center parking lot—drawing lines as long as those at the box office.
Fans engage with the Orion Flight Simulator at NASA’s booth. NASA/Helen Arase Vargas Fans also tested their skills with a crew assembly activity focused on science, technology, engineering, and mathematics, simulating the challenges astronauts face in orbit. NASA’s inflatable mascot, Cosmo, joined the action on the court, posing for photos and adding galactic fun to events like the T-shirt giveaway.
The Houston Rockets mascot Clutch and NASA mascot Cosmo team up on the court at Toyota Center in Houston.NASA/Helen Arase Vargas NASA’s presence brought together the excitement of sports with the wonder of space exploration, inspiring fans to keep shooting for the stars.
View more images from the event below.
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By Space Force
SSC’s annual Fight Tonight competition was launched three years ago, seeking to empower solutions in alignment with the critical Space Force mission of ensuring a secure space domain for all.
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By NASA
ESA/Hubble & NASA, O. Fox, L. Jenkins, S. Van Dyk, A. Filippenko, J. Lee and the PHANGS-HST Team, D. de Martin (ESA/Hubble), M. Zamani (ESA/Hubble) This NASA/ESA Hubble Space Telescope image features NGC 1672, a barred spiral galaxy located 49 million light-years from Earth in the constellation Dorado. This galaxy is a multi-talented light show, showing off an impressive array of different celestial lights. Like any spiral galaxy, shining stars fill its disk, giving the galaxy a beautiful glow. Along its two large arms, bubbles of hydrogen gas shine in a striking red light fueled by radiation from infant stars shrouded within. Near the galaxy’s center are some particularly spectacular stars embedded within a ring of hot gas. These newly formed and extremely hot stars emit powerful X-rays. Closer in, at the galaxy’s very center, sits an even brighter source of X-rays, an active galactic nucleus. This X-ray powerhouse makes NGC 1672 a Seyfert galaxy. It forms as a result of heated matter swirling in the accretion disk around NGC 1672’s supermassive black hole.
See more images of NGC 1672.
Image credit: ESA/Hubble & NASA, O. Fox, L. Jenkins, S. Van Dyk, A. Filippenko, J. Lee and the PHANGS-HST Team, D. de Martin (ESA/Hubble), M. Zamani (ESA/Hubble)
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