The analysis of images from the Perseverance rover carried out by researchers from the USA and France revealed the remains of the delta of an ancient river that flowed into the lake, the bottom of which is now the Jezero crater. In addition, scientists have found evidence of catastrophic floods at a late stage of the lake's existence. The scientists' article was published in the journal Science.
The study of satellite images of Mars showed that for 3.7 billion years, the Jezero crater was a lake into which a river flowed. Analysis of the images of two cameras of the Perseverance rover that landed on Mars in February 2021 additionally revealed that it was subject to heavy floods that transported cobblestones for tens of kilometers, resulting in their fan-shaped accumulation - like that of terrestrial deltas.
Researchers led by experts from NASA's Jet Propulsion Laboratory have put together images of the Kodiak remnant - part of this cluster, partially destroyed by erosion — and were able to clearly identify layers of bottom sediments there. They measured their thickness, slope and transverse extent and concluded that the sediments were deposited by water flowing into the lake, and not by other geological processes. Similar deposits have been observed in the main cluster, which allows researchers to say that it used to be the bottom of the river delta.
In the upper layers of the delta, the researchers found inclusions of large boulders - up to a meter in diameter and weighing up to several tons. According to the researchers, they were brought by floods at a speed of up to nine meters per second, carrying up to three thousand cubic meters of water per second. What caused such cataclysms at the late stage of the lake's life, researchers cannot say. At the same time, the lower layers are formed of much smaller stones - which indicates their initially calm deposition by the river.
Dmitry Yuryev
