The Perseverance rover has made startling scientific discoveries in Jezero Crater. The Mars rover did not find the types of rocks they expected in this ancient, humid environment.
When Perseverance landed on Mars in February 2021, scientists had carefully considered the choice of its landing site. The NASA rover landed in Jezero, a very promising Martian crater. Experts expected the robot to observe some type of rock at the bottom of this crater, but they were surprised.
In a publication of August 25, 2022, NASA reports the latest Perseverance discoveries on site. While scientists thought they were coming across of the sedimentary type rocks, Perseverance found something else: volcanic rocks.
This is quite unexpected, because the crater in which the mission landed once housed a lake, 3.6 billion years ago. However, in this ancient aquatic environment, scientists rather imagined unearthing sedimentary rocks, which would have formed by the accumulation of sand and mud “, as summarized by the CNRS in a press release sent to the press by email. Instead, Perseverance spotted “ igneous rocks deriving from deep or surface volcanic processes “. These igneous rocks must have had interactions with water, says NASA.
What can these amazing rocks tell us about the history of Mars?
That’s not bad news for the Mars mission. On the contrary, as NASA explains, magmatic rocks can provide valuable geological information: they contain crystals, which would make it possible to estimate the date of formation of these rocks. Analyzing these rocks would verify when the lake was present in Jezero Crater, as scientists know it is less ancient than these igneous rocks. Beyond tracing the history of the crater itself, this information would help to understand the broader history of Mars: understanding when its climate was favorable to the formation of lakes and rivers, then when it became cold and dry, as we see it today.
However, magmatic rocks are not the most interesting for another objective pursued by NASA: to find signs of a potential microbial past life on Mars. However, it should be kept in mind that Perseverance is not able to identify life on Mars on its own. And, even at the stage of the return of the samples to Earth, if their analysis suggests signs of life, it will be necessary to remain extremely careful. Unless you see life itself, and can absolutely rule out the hypothesis of contamination, it will be very complex to verify it.