5 min read<\/p>\n
Preparations for Next Moonwalk Simulations Underway (and Underwater)<\/h1>\n<\/div>\n<\/div>\n<\/div>\n\n\n<\/div>It\u2019s a new year on Mars, and while New Year\u2019s means winter in Earth\u2019s northern hemisphere, it\u2019s the start of spring in the same region of the Red Planet. And that means ice is thawing, leading to all sorts of interesting things. JPL research scientist Serina Diniega explains. NASA\/JPL-Caltech<\/figcaption><\/figure>\nInstead of a winter wonderland, the Red Planet\u2019s northern hemisphere goes through an active \u2014 even explosive \u2014 spring thaw.<\/em><\/p>\nWhile New Year\u2019s Eve is around the corner here on Earth, Mars scientists are ahead of the game: The Red Planet completed a trip around the Sun on Nov. 12, 2024, prompting a few researchers to raise a toast.<\/p>\n
But the Martian year, which is 687 Earth days, ends in a very different way in the planet\u2019s northern hemisphere than it does in Earth\u2019s northern hemisphere: While winter\u2019s kicking in here, spring is starting there. That means temperatures are rising and ice is thinning, leading to frost avalanches crashing down cliffsides, carbon dioxide gas exploding from the ground, and powerful winds helping reshape the north pole.<\/p>\n
\u201cSpringtime on Earth has lots of trickling as water ice gradually melts. But on Mars, everything happens with a bang,\u201d said Serina Diniega, who studies planetary surfaces at NASA\u2019s Jet Propulsion Laboratory in Southern California.<\/p>\n
Mars\u2019 wispy atmosphere doesn\u2019t allow liquids to pool on the surface, like on Earth. Instead of melting, ice sublimates, turning directly into a gas. The sudden transition in spring means a lot of violent changes as both water ice and carbon dioxide ice \u2014 dry ice, which is much more plentiful on Mars than frozen water \u2014 weaken and break.<\/p>\n
\u201cYou get lots of cracks and explosions instead of melting,\u201d Diniega said. \u201cI imagine it gets really noisy.\u201d<\/p>\n
Using the cameras and other sensors aboard NASA\u2019s Mars Reconnaissance Orbiter (MRO<\/a>), which launched in 2005, scientists study all this activity to improve their understanding of the forces shaping the dynamic Martian surface. Here\u2019s some of what they track.<\/p>\nFrost Avalanches<\/strong><\/h3>\nIn 2015, MRO\u2019s High-Resolution Imaging Science Experiment (HiRISE<\/a>) camera captured a 66-foot-wide (20-meter-wide) chunk of carbon dioxide frost<\/a> in freefall. Chance observations like this are reminders of just how different Mars is from Earth, Diniega said, especially in springtime, when these surface changes are most noticeable.<\/p>\n\n\n\n![\"66-foot-wide](\"https:\/\/www.nasa.gov\/wp-content\/uploads\/2024\/12\/e1-frost-avalanche-pia19961-already-in-pj.jpg?w=2048\")
<\/a><\/figure>\nMartian spring involves lots of cracking ice, which led to this 66-foot-wide (20-meter-wide) chunk of carbon dioxide frost captured in freefall by the HiRISE camera aboard NASA\u2019s Mars Reconnaissance Orbiter in 2015<\/div>\nNASA\/JPL-Caltech\/University of Arizona<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n\u201cWe\u2019re lucky we\u2019ve had a spacecraft like MRO observing Mars for as long as it has,\u201d Diniega said. \u201cWatching for almost 20 years has let us catch dramatic moments like these avalanches.\u201d<\/p>\n
Gas Geysers<\/strong><\/h3>\nDiniega has relied on HiRISE to study another quirk of Martian springtime: gas geysers that blast out of the surface, throwing out dark fans of sand and dust. These explosive jets form due to energetic sublimation of carbon dioxide ice. As sunlight shines through the ice, its bottom layers turn to gas, building pressure until it bursts into the air, creating those dark fans of material.<\/p>\n
\n\n\n![\"Light](\"https:\/\/www.nasa.gov\/wp-content\/uploads\/2024\/12\/e2-pia22881-already-in-pj.jpg?w=2048\")
<\/a><\/figure>\nAs light shines through carbon dioxide ice on Mars, it heats up its bottom layers, which, rather than melting into a liquid, turn into gas. The buildup gas eventually results in explosive geysers that toss dark fans of debris on to the surface.<\/div>\nNASA\/JPL-Caltech\/University of Arizona<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\nBut to see the best examples of the newest fans, researchers will have to wait until December 2025, when spring starts in the southern hemisphere. There, the fans are bigger and more clearly defined.<\/p>\n
Spiders<\/strong><\/h3>\nAnother difference between ice-related action in the two hemispheres: Once all the ice around some northern geysers has sublimated in summer, what\u2019s left behind in the dirt are scour marks that, from space, look like giant spider legs. Researchers recently re-created this process<\/a> in a JPL lab.<\/p>\n\n\n\n![\"Spider-shaped](\"https:\/\/www.nasa.gov\/wp-content\/uploads\/2024\/09\/1-pia12249-beige-spiders-16.jpg?w=1826\")
<\/a><\/figure>\nSometimes, after carbon dioxide geysers have erupted from ice-covered areas on Mars, they leave scour marks on the surface. When the ice is all gone by summer, these long scour marks look like the legs of giant spiders.<\/div>\nNASA\/JPL-Caltech\/University of Arizona<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\nPowerful Winds<\/strong><\/h3>\nFor Isaac Smith of Toronto\u2019s York University, one of the most fascinating subjects in springtime is the Texas-size ice cap<\/a> at Mars\u2019 north pole. Etched into the icy dome are swirling troughs, revealing traces of the red surface below. The effect is like a swirl of milk in a caf\u00e9 latte.<\/p>\n\u201cThese things are enormous,\u201d Smith said, noting that some are a long as California. \u201cYou can find similar troughs in Antarctica but nothing at this scale.\u201d<\/p>\n
\n\n\n![\"Ice](\"https:\/\/www.nasa.gov\/wp-content\/uploads\/2024\/12\/e4-powerful-winds-pia13163-already-in-pj.jpg?w=1280\")
<\/a><\/figure>\nAs temperatures rise, powerful winds kick up that carve deep troughs into the ice cap of Mars\u2019 north pole. Some of these troughs are as long as California, and give the Martian north pole its trademark swirls. This image was captured by NASA\u2019s now-inactive Mars Global Surveyor.<\/div>\nNASA\/JPL-Caltech\/MSSS<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\nFast, warm wind has carved the spiral shapes over eons, and the troughs act as channels for springtime wind gusts that become more powerful as ice at the north pole starts to thaw. Just like the Santa Ana winds in Southern California or the Chinook winds in the Rocky Mountains, these gusts pick up speed and temperature as they ride down the troughs \u2014 what\u2019s called an adiabatic process.<\/p>\n
Wandering Dunes<\/strong><\/h3>\nThe winds that carve the north pole\u2019s troughs also reshape Mars\u2019 sand dunes<\/a>, causing sand to pile up on one side while removing sand from the other side. Over time, the process causes dunes to migrate, just as it does with dunes on Earth.<\/p>\nThis past September, Smith coauthored a paper<\/a> detailing how carbon dioxide frost settles on top of polar sand dunes during winter, freezing them in place. When the frost all thaws away in the spring, the dunes begin migrating again.<\/p>\n\n\n\n![\"Martian](\"https:\/\/www.nasa.gov\/wp-content\/uploads\/2024\/12\/e5-pia26517-hirise-views-frosty-martian-dunes.jpg?w=2048\")
<\/a><\/figure>\nSurrounded by frost, these Martian dunes in Mars\u2019 northern hemisphere were captured from above by NASA\u2019s Mars Reconnaissance Orbiter using its HiRISE camera on Sept. 8, 2022. <\/div>\nNASA\/JPL-Caltech\/University of Arizona<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\nEach northern spring is a little different, with variations leading to ice sublimating faster or slower, controlling the pace of all these phenomena on the surface. And these strange phenomena are just part of the seasonal changes on Mars: the southern hemisphere has its own unique activity.<\/p>\n
More About MRO<\/strong><\/h3>\nThe University of Arizona, in Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., in Boulder, Colorado. NASA\u2019s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA\u2019s Science Mission Directorate, Washington.<\/p>\n
For more information, visit:<\/p>\n
https:\/\/science.nasa.gov\/mission\/mars-reconnaissance-orbiter<\/a><\/p>\nNews Media Contacts<\/strong><\/h3>\nAndrew Good
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-2433
andrew.c.good@jpl.nasa.gov<\/a><\/p>\nKaren Fox \/ Molly Wasser
NASA Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov<\/a>\u00a0\/ molly.l.wasser@nasa.gov<\/a><\/p>\n2024-177<\/p>\n
\n\n\n\n\n\nShare<\/h2>\n<\/p><\/div>\n\n
Instead of a winter wonderland, the Red Planet\u2019s northern hemisphere goes through an active \u2014 even explosive \u2014 spring thaw.<\/em><\/p>\n While New Year\u2019s Eve is around the corner here on Earth, Mars scientists are ahead of the game: The Red Planet completed a trip around the Sun on Nov. 12, 2024, prompting a few researchers to raise a toast.<\/p>\n But the Martian year, which is 687 Earth days, ends in a very different way in the planet\u2019s northern hemisphere than it does in Earth\u2019s northern hemisphere: While winter\u2019s kicking in here, spring is starting there. That means temperatures are rising and ice is thinning, leading to frost avalanches crashing down cliffsides, carbon dioxide gas exploding from the ground, and powerful winds helping reshape the north pole.<\/p>\n \u201cSpringtime on Earth has lots of trickling as water ice gradually melts. But on Mars, everything happens with a bang,\u201d said Serina Diniega, who studies planetary surfaces at NASA\u2019s Jet Propulsion Laboratory in Southern California.<\/p>\n Mars\u2019 wispy atmosphere doesn\u2019t allow liquids to pool on the surface, like on Earth. Instead of melting, ice sublimates, turning directly into a gas. The sudden transition in spring means a lot of violent changes as both water ice and carbon dioxide ice \u2014 dry ice, which is much more plentiful on Mars than frozen water \u2014 weaken and break.<\/p>\n \u201cYou get lots of cracks and explosions instead of melting,\u201d Diniega said. \u201cI imagine it gets really noisy.\u201d<\/p>\n Using the cameras and other sensors aboard NASA\u2019s Mars Reconnaissance Orbiter (MRO<\/a>), which launched in 2005, scientists study all this activity to improve their understanding of the forces shaping the dynamic Martian surface. Here\u2019s some of what they track.<\/p>\n In 2015, MRO\u2019s High-Resolution Imaging Science Experiment (HiRISE<\/a>) camera captured a 66-foot-wide (20-meter-wide) chunk of carbon dioxide frost<\/a> in freefall. Chance observations like this are reminders of just how different Mars is from Earth, Diniega said, especially in springtime, when these surface changes are most noticeable.<\/p>\n \u201cWe\u2019re lucky we\u2019ve had a spacecraft like MRO observing Mars for as long as it has,\u201d Diniega said. \u201cWatching for almost 20 years has let us catch dramatic moments like these avalanches.\u201d<\/p>\n Diniega has relied on HiRISE to study another quirk of Martian springtime: gas geysers that blast out of the surface, throwing out dark fans of sand and dust. These explosive jets form due to energetic sublimation of carbon dioxide ice. As sunlight shines through the ice, its bottom layers turn to gas, building pressure until it bursts into the air, creating those dark fans of material.<\/p>\n But to see the best examples of the newest fans, researchers will have to wait until December 2025, when spring starts in the southern hemisphere. There, the fans are bigger and more clearly defined.<\/p>\n Another difference between ice-related action in the two hemispheres: Once all the ice around some northern geysers has sublimated in summer, what\u2019s left behind in the dirt are scour marks that, from space, look like giant spider legs. Researchers recently re-created this process<\/a> in a JPL lab.<\/p>\n For Isaac Smith of Toronto\u2019s York University, one of the most fascinating subjects in springtime is the Texas-size ice cap<\/a> at Mars\u2019 north pole. Etched into the icy dome are swirling troughs, revealing traces of the red surface below. The effect is like a swirl of milk in a caf\u00e9 latte.<\/p>\n \u201cThese things are enormous,\u201d Smith said, noting that some are a long as California. \u201cYou can find similar troughs in Antarctica but nothing at this scale.\u201d<\/p>\n Fast, warm wind has carved the spiral shapes over eons, and the troughs act as channels for springtime wind gusts that become more powerful as ice at the north pole starts to thaw. Just like the Santa Ana winds in Southern California or the Chinook winds in the Rocky Mountains, these gusts pick up speed and temperature as they ride down the troughs \u2014 what\u2019s called an adiabatic process.<\/p>\n The winds that carve the north pole\u2019s troughs also reshape Mars\u2019 sand dunes<\/a>, causing sand to pile up on one side while removing sand from the other side. Over time, the process causes dunes to migrate, just as it does with dunes on Earth.<\/p>\n This past September, Smith coauthored a paper<\/a> detailing how carbon dioxide frost settles on top of polar sand dunes during winter, freezing them in place. When the frost all thaws away in the spring, the dunes begin migrating again.<\/p>\n Each northern spring is a little different, with variations leading to ice sublimating faster or slower, controlling the pace of all these phenomena on the surface. And these strange phenomena are just part of the seasonal changes on Mars: the southern hemisphere has its own unique activity.<\/p>\n The University of Arizona, in Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., in Boulder, Colorado. NASA\u2019s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA\u2019s Science Mission Directorate, Washington.<\/p>\n For more information, visit:<\/p>\n https:\/\/science.nasa.gov\/mission\/mars-reconnaissance-orbiter<\/a><\/p>\n Andrew Good Karen Fox \/ Molly Wasser 2024-177<\/p>\nFrost Avalanches<\/strong><\/h3>\n
<\/a><\/figure>Gas Geysers<\/strong><\/h3>\n
<\/a><\/figure>Spiders<\/strong><\/h3>\n
<\/a><\/figure>Powerful Winds<\/strong><\/h3>\n
<\/a><\/figure>Wandering Dunes<\/strong><\/h3>\n
<\/a><\/figure>More About MRO<\/strong><\/h3>\n
News Media Contacts<\/strong><\/h3>\n
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-2433
andrew.c.good@jpl.nasa.gov<\/a><\/p>\n
NASA Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov<\/a>\u00a0\/ molly.l.wasser@nasa.gov<\/a><\/p>\nShare<\/h2>\n<\/p><\/div>\n