Scientists had previously speculated the Jezero crater could have been a lake, and a new study published Friday in Science Advances confirms that suspicion.
A team of researchers led by UCLA and The University of Oslo concluded that at some point, the crater filled with water and deposited layers of sediment on its floor. The lake shrank, and sediments carried by the river that fed it created a delta.
Using the Perseverance rover‘s ground-penetrating radar, researchers discovered how those sediments formed over time.
“From orbit we can see a bunch of different deposits, but we can’t tell for sure if what we’re seeing is their original state, or if we’re seeing the conclusion of a long geological story,” David Paige, a UCLA professor and lead author of the paper, said in a news release. “To tell how these things formed, we need to see below the surface.”
Perseverance scoured the Jezero crater between May and December 2022, firing radar waves downward and measuring pulses reflected back up from about 20 meters below the surface. The resulting images show rock layers that can be interpreted to determine how the sediments were formed.
In this case, researchers found the sediments on the crater floor look similar to those deposited in lakes on Earth.
“The regularity and horizontality of the basal delta sediments observed in the radar cross sections indicate that they were deposited in a low-energy lake environment,” researchers wrote.
It’s possible that microbial life could have lived in the crater when it was filled with water, and if life did exists on Mars, sediment samples would contain signs of the remains.
Perseverance has been collecting samples from Mars since it landed there in 2021 and will eventually be brought back to Earth.
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Author: Tyler Wornell