The findings– released in AGU Advances on December 27, 2021– center on the chloride salt deposits left as icy meltwater streaming throughout the landscape evaporated.
While the shape of certain valley networks hinted that water might have flowed on Mars that just recently, the salt deposits offer the very first mineral proof verifying the presence of liquid water. The discovery raises brand-new questions about the length of time microbial life could have survived on Mars, if it ever formed at all. In the world, at least, where there is water, there is life.
The research studys lead author, Ellen Leask, carried out much of the research as part of her doctoral work at Caltech in Pasadena. She and Caltech professor Bethany Ehlmann utilized data from the MRO instrument called the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) to map the chloride salts across the clay-rich highlands of Mars southern hemisphere– terrain pockmarked by impact craters. These craters were one key to dating the salts: The fewer craters a surface has, the younger it is. By counting the number of craters on a location of the surface, scientists can approximate its age.
MRO has 2 video cameras that are ideal for this purpose. The Context Camera, with its black-and-white wide-angle lens, helps researchers map the extent of the chlorides. To focus, researchers turn to the High-Resolution Imaging Science Experiment (HiRISE) color electronic camera, allowing them to see information as small as a Mars rover from area. (See image below for an example.).
Each of these two images were taken by the HiRISE cam on NASAs Mars Reconnaissance Orbiter. The first image shows the rover, which appears as a gray speck, at an area called “Woodland Bay” (leading center). Look carefully and you can even see the rovers tracks arcing to the right of the 2nd image.
Utilizing both electronic cameras to develop digital elevation maps, Leask and Ehlmann found that much of the salts were in depressions– when home to shallow ponds– on gently sloping volcanic plains. The scientists likewise found winding, dry channels nearby– previous streams that when fed surface runoff (from the periodic melting of ice or permafrost) into these ponds. Crater counting and evidence of salts on top of volcanic terrain allowed them to date the deposits.
” What is incredible is that after more than a years of offering high-resolution image, stereo, and infrared information, MRO has actually driven brand-new discoveries about the nature and timing of these river-connected ancient salt ponds,” stated Ehlmann, CRISMs deputy principal detective. Her co-author, Leask, is now a post-doctoral scientist at Johns Hopkins Universitys Applied Physics Laboratory, which leads CRISM.
The salt minerals were very first discovered 14 years back by NASAs Mars Odyssey orbiter, which introduced in 2001. MRO, which has higher-resolution instruments than Odyssey, introduced in 2005 and has actually been studying the salts, amongst numerous other features of Mars, ever given that. Both are managed by NASAs Jet Propulsion Laboratory in Southern California.
” Part of the value of MRO is that our view of the world keeps getting more comprehensive with time,” said Leslie Tamppari, the missions deputy project researcher at JPL. “The more of the world we map with our instruments, the much better we can understand its history.”.
Referral: “Evidence for Deposition of Chloride on Mars From Small-Volume Surface Water Events Into the Late Hesperian-Early Amazonian” by Ellen K. Leask and Bethany L. Ehlmann, 27 December 2021, AGU Advances.DOI: 10.1029/ 2021AV000534.
More About the Mission.
JPL, a division of Caltech in Pasadena, California, handles the MRO objective for NASAs Science Mission Directorate in Washington. The University of Arizona, in Tucson, operates HiRISE, which was built by Ball Aerospace & & Technologies Corp., in Boulder, Colorado. MARCI and the Context Camera were both constructed and are operated by Malin Space Science Systems in San Diego.
NASAs Mars Reconnaissance Orbiter used its Context Camera to record this image of Bosporos Planum, an area on Mars. While the shape of certain valley networks hinted that water may have flowed on Mars that recently, the salt deposits supply the first mineral proof validating the existence of liquid water. She and Caltech teacher Bethany Ehlmann used data from the MRO instrument called the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) to map the chloride salts throughout the clay-rich highlands of Mars southern hemisphere– terrain pockmarked by impact craters. The salt minerals were first discovered 14 years back by NASAs Mars Odyssey orbiter, which introduced in 2001. MRO, which has higher-resolution instruments than Odyssey, introduced in 2005 and has actually been studying the salts, among many other features of Mars, ever given that.
NASAs Mars Reconnaissance Orbiter used its Context Camera to catch this picture of Bosporos Planum, an area on Mars. The white specks are salt deposits discovered within a dry channel. The largest effect crater in the scene is nearly 1 mile (1.5 kilometers) throughout. Credit: NASA/JPL-Caltech/MSSS
Caltech scientists utilized the Mars Reconnaissance Orbiter to determine that surface area water left salt minerals behind as recently as 2 billion years back.
Mars once rippled with ponds and rivers billions of years ago, providing a prospective environment for microbial life. As the planets atmosphere thinned gradually, that water vaporized, leaving the frozen desert world that NASAs Mars Reconnaissance Orbiter (MRO) research studies today.
Its frequently believed that Mars water evaporated about 3 billion years ago. However two researchers studying information that MRO has collected at Mars over the last 15 years have actually discovered proof that reduces that timeline substantially: Their research reveals signs of liquid water on the Red Planet as just recently as 2 billion to 2.5 billion years ago, implying water flowed there about a billion years longer than previous price quotes.