Evidence of ancient lake sediments at the base of Jezero Crater on Mars offers new hope for finding traces of life in samples collected by NASA's Perseverance rover.
perseverance It landed on February 18, 2021, inside the 28-mile-wide (45-kilometer) Red Planet. Jezero CraterWhich is believed to have previously contained a large lake and a river delta. The spacecraft has been scouring the crater for signs of past life and collecting and storing dozens of them Samples All the way to a possible future return to Earth.
Using the rover's Radar Imaging Subsurface Mars Experiment (RIMFAX) instrument, researchers from the University of California, Los Angeles (UCLA) and the University of Oslo have uncovered new evidence about how layers of sediment form over time on the surface of Mars. the pit The floor, according to A statement.
“From orbit we can see a range of different deposits, but we cannot say with certainty whether what we are seeing is their original state, or whether we are witnessing the end of a long geological story,” said David Page, the first to discover it. The study's author, deputy principal investigator at RIMFAX and a UCLA professor, said in the statement. “To know how these things formed, we have to see beneath the surface.”
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Perseverance also travels across a surface Marsthe RIMFAX instrument sends radar waves downward at 4-inch (10-centimeter) intervals and measures reflected pulses from depths of about 65.6 feet (20 meters) below the surface to create a subsurface profile of the crater floor.
the remfax The data showed evidence of sediments deposited by the water that once filled the crater. It is possible that microbial life lived in the hole at this time, and if so Life once existed on MarsSediment samples from this area contain signs of its remains.
Two distinct periods of sedimentation occurred, creating layers of sediment on the Earth's surface Hole floor Which appear regular and horizontal, very similar to the layers we see on Earth. Fluctuations in the lake's water levels have caused some sedimentary deposits to form an enormous delta, which… Perseverance passed Between May and December 2022, according to the statement.
Radar measurements also show an uneven crater floor below the delta, which is likely due to erosion before sediments were first deposited. Then, as the lake dried up over time, the sedimentary layers in the crater eroded away, forming the geological features visible on Mars today.
“The changes we see preserved in the rocky record are driven by large-scale changes in the Martian environment,” Page said in the statement. “It's great that we can see so much evidence of change in such a small geographical area, which allows us to do this [to] “Extending our findings to include the entire crater volume.”
Their findings were published today (January 26) in the journal Science Advances.
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