Astro Blog

https://www.nytimes.com/2022/10/27/science/mars-meteorites-impacts-seismic.html By  Kenneth Chang , The New York Times.  Excerpt: The exquisitely sensitive seismometer on NASA’s InSight lander dutifully recorded the burst of seismic vibrations and then dispatched the data, a gift of science, to Earth the next day. The InSight scientists were busy celebrating the holidays. When they studied the tremor in detail in early January, it looked different from the more than 1,000 marsquakes that the stationary spacecraft had recorded during its mission to study the insides of the red planet. ...In scientific papers published Thursday, scientists using data from two NASA spacecraft reveal that the seismic event was not the cracking of rocks from the internal stresses of the red planet. Instead, it was shock waves emanating from a space rock hitting Mars. The discovery will help scientists better understand what is inside Mars and serves as a reminder that just like Earth, Mars gets wha...

https://www.nytimes.com/2021/03/19/science/mars-water-missing.html Source:  By  Kenneth Chang , The New York Times.  Excerpt: Mars once had rivers, lakes and seas. Although the planet is now desert dry, scientists say most of the water is still there, just locked up in rocks. ...most of the water, a new study concludes, went down, sucked into the red planet’s rocks. And there it remains, trapped within minerals and salts. Indeed, as much as 99 percent of the water that once flowed on Mars could still be there, the researchers estimated in  a paper published this week in the journal Science.  Data from the past two decades of robotic missions to Mars, including NASA’s Curiosity rover and the Mars Reconnaissance Orbiter, showed a wide distribution of what geologists call hydrated minerals.... 

https://eos.org/articles/history-of-marss-water-seen-through-the-lens-of-gale-crater Source:   By Ramin Skibba, AGU-Eos Excerpt: Past research indicates that the Red Planet may have been a very different world more than 3 billion years ago, with warmer weather, flowing rivers, lakes, and possibly even oceans of liquid water. These conditions would have been much more hospitable to nascent life-forms, if they existed. However, recent research is uncovering a different story. “There have been two competing viewpoints about the Martian climate at this time: the traditional warm-and-wet view and the view that Mars was always cold and icy,” explained Jeffrey Andrews-Hanna, a Mars-focused planetary scientist at the University of Arizona. Now, enter a third scenario: Billions of years ago, “Mars never really experienced a temperate Earth-like climate,” Andrews-Hanna added. Instead, a body of recent evidence points to an arid early Mars with pockets of wet patches.... 

http://science.sciencemag.org/content/359/6372/199 Source:   By Colin M. Dundas et al, Science Abstract: Thick deposits cover broad regions of the Martian mid-latitudes with a smooth mantle; erosion in these regions creates scarps that expose the internal structure of the mantle. We investigated eight of these locations and found that they expose deposits of water ice that can be >100 meters thick, extending downward from depths as shallow as 1 to 2 meters below the surface. The scarps are actively retreating because of sublimation of the exposed water ice. The ice deposits likely originated as snowfall during Mars’ high-obliquity periods and have now compacted into massive, fractured, and layered ice. We expect the vertical structure of Martian ice-rich deposits to preserve a record of ice deposition and past climate.... 

https://www.jpl.nasa.gov/news/news.php?feature=7005 Source:   By Jet Propulsion Laboratory News 2017-11-20.  . For GSS A Changing Cosmos chapter 7. Excerpt: Fast Facts: › Seasonal dark streaks on Mars have been described as possible signs of flowing water; a new study shows they are a better fit to dry flow processes. › The steepness of more than 150 of these features was assessed with a telescopic camera on a NASA Mars orbiter. › The findings add to evidence that these environments may be too dry for microbes to thrive, despite the presence of water in hydrated salts. › How seasonal warming triggers these streaks is still a puzzle, and water may be involved.... 

Source:   By Kenneth Chang, The New York Times Excerpt: An ice sheet with more water than Lake Superior may slake the thirst of future astronauts living on Mars. Using radar soundings from NASA’s Mars Reconnaissance Orbiter spacecraft, scientists probed what lies in Utopia Planitia, a 2,000-mile-wide basin within an ancient impact crater. For decades, the region looked intriguing because of polygonal cracking and scalloped depressions in the landscape. In places on Earth like the Canadian Arctic, patterns like these arise from ice beneath the surface. The ground cracks as ice underneath expands and contracts with the changing temperatures; the scallops, as if carved by an ice cream scoop, are places where the surface sinks as the ice melts. “We’d say, ‘It looks like there’s ground ice there,’” Cassie Stuurman, a graduate student at the University of Texas at Austin, said about Utopia Planitia. “What we haven’t known is how much is there.”n ...Ms. Stuurman, the lead author of an...

Source:   By Shannon Hall, EoS-Earth & Space Science News (AGU) Excerpt: Massive meteorites likely slammed into a Martian ocean billions of years ago, unleashing tsunami waves up to 120 meters tall, a close study of a region of the Red Planet's terrain has found.... https://eos.org/articles/tsunamis-splashed-ancient-mars

Source:    High Resolution Imaging Science Experiment (HiRISE), NASA  NASA - High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. See image of an afternoon whirlwind on Mars lofting a twisting column of dust more than half a mile (800 meters) high and casting a shadow on the Martian ground. Image location:  www.nasa.gov/images/content/628440main_pia15116-673.jpg www.nasa.gov/mission_pages/MRO/news/mro20120307.html

Source:    NASA RELEASE : 11-369 Excerpt: ...A new NASA study suggests if life ever existed on Mars, the longest lasting habitats were most likely below the Red Planet's surface. ...A new interpretation of years of mineral-mapping data … suggests Martian environments with abundant liquid water on the surface existed only during short episodes. …Discovery of clay minerals on Mars in 2005 indicated the planet once hosted warm, wet conditions. …This new study supports an alternative hypothesis that persistent warm water was confined to the subsurface and many erosional features were carved during brief periods when liquid water was stable at the surface.  www.nasa.gov/home/hqnews/2011/nov/HQ_11-369_Martian_Clay.html

Source:    NASA RELEASE: 11-245   Excerpt: Observations from NASA's Mars Reconnaissance Orbiter (MRO) have revealed possible flowing water during the warmest months on Mars. "NASA's Mars Exploration Program keeps bringing us closer to determining whether the Red Planet could harbor life in some form," NASA Administrator Charles Bolden said, "and it reaffirms Mars as an important future destination for human exploration." Dark, finger-like features appear and extend down some Martian slopes during late spring through summer, fade in winter, and return during the next spring.  …"The best explanation for these observations so far is the flow of briny water," said Alfred McEwen of the University of Arizona, Tucson. ...For more information about MRO, visit:  www.nasa.gov/home/hqnews/2011/aug/HQ_11-245_Mars_Water.html

Source:   Johanna L. Miller, Physics Today Excerpt: Radar data reveal a solid reservoir that contains almost as much carbon dioxide as the planet’s entire atmosphere. …because Mars doesn’t have a large moon, it… wobbles by up to tens of degrees on time scales of hundreds of thousands of years…. a profound effect on the planet’s polar icecaps. Substantial amounts of material sublimate and are redeposited, creating a complex structure of overlapping layered deposits. Most of those deposits are primarily water ice. …but now, data from the Mars Reconnaissance Orbiter reveal at least one large deposit of CO2 ice…if ...vaporized, as it certainly was at some point in the past and will be again in the future, it could nearly double the average pressure of Mars’s thin, CO2-based atmosphere. See also: www.nasa.gov/mission_pages/MRO/news/mro20100526.html physicstoday.org/resource/1/phtoad/v64/i6/p12_s1

Source:    NASA RELEASE: 11-118 Excerpt: NASA's Mars Reconnaissance Orbiter (MRO) has discovered the total amount of atmosphere on Mars changes dramatically as the tilt of the planet's axis varies. This process can affect the stability of liquid water if it exists on the Martian surface and increase the frequency and severity of Martian dust storms. …a large, buried deposit of frozen carbon dioxide, or dry ice, at the Red Planet's south pole … has a volume similar to Lake Superior's nearly 3,000 cubic miles. The deposit holds up to 80 percent as much carbon dioxide as today's Martian atmosphere.  …"When you include this buried deposit, Martian carbon dioxide right now is roughly half frozen and half in the atmosphere, but at other times it can be nearly all frozen or nearly all in the atmosphere," For more information about MRO, visit: www.nasa.gov/mro www.nasa.gov/home/hqnews/2011/apr/HQ_11-118_Mars_Atmosphere.html

Source:   NASA Excerpt:  ...NASA's Mars Reconnaissance Orbiter (MRO) has discovered the total amount of atmosphere on Mars changes dramatically as the tilt of the planet's axis varies. This process can affect the stability of liquid water if it exists on the Martian surface and increase the frequency and severity of Martian dust storms. Researchers using MRO's ground-penetrating radar identified a large, buried deposit of frozen carbon dioxide, or dry ice, at the Red Planet's south pole. The scientists suspect that much of this carbon dioxide enters the planet's atmosphere and swells the atmosphere's mass when Mars' tilt increases. ...The deposit holds up to 80 percent as much carbon dioxide as today's Martian atmosphere.... www.nasa.gov/home/hqnews/2011/apr/HQ_11-118_Mars_Atmosphere.html

Source:   NASA/JPL Excerpt: For 40 years researchers have puzzled over a strange pattern of ice spirals and chasms around the Martian north pole. New data from NASA's Mars Reconnaissance Orbiter solve the mystery. science.nasa.gov/science-news/science-at-nasa/2010/16jun_martianspirals/

Source:   Phil Plait, Astronomy, Pretty Pictures, Science  Excerpt: Does liquid water still flow on Mars? We know that in the distant past — like, a billion years ago — liquid water was abundant on Mars. We also know that water currently exists on Mars in the form of ice, .... But can there still be liquid water flowing on Mars, even if only for a very, very short time? Maybe. ... HiRISE image shows a small region of a Martian crater named Russel… There are a lot of sand dunes in it, and … many gullies as well.... Sometimes, these gullies can form due to the presence of dry ice: … the dry ice turns into a gas, dislodging material and letting it roll downhill. …But these Russell Crater gullies are different. …The gullies do widen where two tributaries meet, which is exactly as you’d expect from flowing material. http://blogs.discovermagazine.com/badastronomy/2010/04/12/new-evidence-of-transient-liquid-water-on-mars/