A new analysis of terrestrial deposition and erosion patterns beneath a dry lake bed in Mars' Jezero Crater indicates the process took place over eons, dramatically improving the chances that soil samples collected at the site by NASA's diligence may contain signs of ancient life.
Although no exact timeline has yet been set for a joint European Space Agency/NASA mission to recover soil samples from Perseverance, the odds of finding signs of ancient life are significantly increased by the fact that the Jezero crater lake has existed in multiple geological phases. Samples.
Researchers have long suspected that deep sedimentary layers lie beneath Jezero
Over the past few decades, images captured by satellites orbiting Mars have long hinted at the idea of eroded surface layers in the region. However, the researchers knew that closer analysis with the Perseverance's ground-penetrating radar was the only way to confirm those suspicions.
„From orbit, we can see different deposits, but we can't be sure if what we're seeing is their original state or the end of a long geologic story.” said David Paige, a UCLA professor of Earth, planetary and space sciences and first author of the paper describing the findings. „To tell how these things evolved, we have to look below the surface.”
Fortunately, Perseverance mission planners included the Radar Imager for Mars Surface Examination, or RIMFAX, as one of the rover's seven instruments. Similar to ground-penetrating radar used on Earth, RIFMAX sends radar waves directly into the Martian surface and then reads their reflections as they bounce off different sediment layers.
Ground-penetrating radar confirms satellite imagery
To scan the floor of the river delta that once fed the Jezero crater, Perseverance used RIMFAX to send radar pulses into the ground every 10 centimeters. When those pulses are reflected from a depth of 20 meters below the surface, the instrument captures that data. Because of the system's prolonged use on Earth, scientists have discovered how to study the structure and composition of surface layers from those reflections.
„Some geologists say that radar's ability to see beneath the surface is deceptive,” said Paige, RIMFAX's deputy principal investigator.
The process took place between May and December 2021, giving researchers the opportunity to collect data from a wider area in the delta. As researchers reported In the latest version Scientific advancesThe radar revealed strong evidence that ancient lake sediments in the Jezero Crater have been eroded over the years.
„Radar confirms that inferences about the Gezero Crater's geologic history based on space-derived images of Mars are accurate, with periods of deposition and erosion occurring during environmental changes,” explain the UCLA and University of Oslo researchers.
The findings raise the odds for signs of ancient life in Jezero soil samples
Although Perseverance has completed numerous missions and made countless significant discoveries about the Red Planet since landing in February 2021, some of the work the SUV-sized rover has done, down to the soil samples it has collected and stored, has shocked researchers and the public alike. Finally returning to Earth. Not only did the original mission planners choose to study Jezero in the hope that an ancient lake might have existed at the site, but the exact areas the vehicle explored in the 30-mile-wide crater were chosen as the most likely locations to look for signs of antiquity. Life.
Also, they chose specific sites within those study sites to select specimens with the highest chance of life. Therefore, ensuring that the rover's findings are consistent with the satellite images used by mission planners and that they are indeed correctly selected should increase the incentive to fund a sample return mission.
„The changes we see in the rock record are driven by large-scale changes in the Martian environment,” Paige said of the timescales revealed by the findings. „It's great that we can see so many sources of change in such a small geographic area, which allows us to. [to] Extend our findings to the full crater.”
Ultimately, the sooner those samples can be returned to Earth, the sooner researchers can use more advanced tools and techniques to analyze them. Based on these latest findings, researchers may find signs of ancient extraterrestrial life exactly where they hoped to find it.
„If life ever existed on Mars, the rover's diligent checking of lake sediments at the base of the Jezero Crater strengthens the belief that traces of life could be found in the crater,” the researchers explain.
Christopher Plein is a science fiction and fantasy novelist and the chief science writer at The Debrief. Follow him and connect X, To know about his books plainfiction.comOr email him directly at [email protected].