's Perseverance rover NASA arrived at Jezero Crater on Mars in February 2021. Until then, scientists had studied the crater through observations from spacecraft such as the Mars Express satellite and Mars Reconnaissance Orbiter .
But now, thanks to Perseverance, scientists can make better estimates about the past of this region of Mars, which once had water, as it was a lake. Since the Perseverance rover's primary mission is to discover signs that life once existed on Mars, the new information is crucial for where scientists should look for those signs.
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Today, there is no liquid water on the surface of Mars. It is a very cold, very dry world, but in the past the planet was warmer and wetter. The 28-mile-wide Jezero crater was once a lake, and although the water has long since disappeared, evidence of its existence and the way it moved is evident . A recent paper published in Science describes large rocks that may contain geological evidence of the interior of Mars .
According to Nicolas Mangold, a scientist at the University of Nantes in France and lead author of the new paper, the findings suggest that there was a lake in the past, but it was slightly different from what we expect. Jezero Crater was a quiet lake 3.7 billion years ago. A small river flowed into the lake, and sometimes the water was so strong that it could carry large rocks and throw them into the lake. The huge rocks are still there today.
See also: NASA confirms collection of rocky sample from Mars
Scientists reported over 300 rocks and stones. The largest rocks were nearly 5 feet wide. The scientist also said that the rocks come from floods and other related phenomena that may be related to some change in the Martian climate.
Ken Farley, Perseverance project scientist, described the complexity of the Jezero Lake system at a NASA press conference in July:
"One of the hypotheses we're trying to examine is that the lake that once filled Jezero wasn't there just once, but that it went through multiple episodes of filling, drying, and filling again," Farley said. "That's really important because it means we'll have multiple time periods in which we could potentially learn about environmental conditions on Mars, and we have multiple time periods in which we could look for ancient life that might have existed on the planet."
Researchers still have a lot to learn about the crater and ancient lake on Mars. New images from NASA's Perseverance rover have helped scientists conclude that the level of Jezero Lake was about 328 feet lower than previously thought. The rover is moving toward the crater's edge to uncover more clues.
Now, researchers will pay closer attention to places where other rocks and elements are likely to be found to better understand this change in the liquid element of Mars.
See also: NASA: "Volcanic eruptions" on Mars can hide the Sun
NASA's Perseverance's biggest task is to search for and collect evidence that any life on Mars may have left behind. The new data is helping scientists figure out where to look for possible fossils.
Experts believe that these fossils, if they exist, will not be fossils of entire creatures that may have lived on Mars, but traces they have left behind.
It's amazing that NASA's Perseverance rover and scientists have already uncovered so much about the history of Jezero Crater through images of the rocks in the crater. Regardless of whether fossils are found or not, the Martian samples that make it back to Earth will be impressive.
Source: Gizmodo
