The Perseverance rover has made exciting findings about the location it is exploring on Mars, the Jezero crater, helping scientists to understand more about this region and its geological history.
Two major findings are that the rocks in the Jezero crater have been in the presence of water multiple times and that some contain organic molecules. These organic molecules can be created by either biological or non-biological processes, so they aren’t confirmation that life existed there, but they are a good sign that if there was once life there it should be possible to find evidence of this fact.
In addition, the team has found that the rocks in the crater are igneous, having formed from lava flows or magma. This answers a major question about the composition of the crater, as previously researchers were unsure if the rocks there were igneous or sedimentary.
“I was beginning to despair we would never find the answer,” said Perseverance Project Scientist Ken Farley of Caltech in a statement. “But then our PIXL instrument got a good look at the abraded patch of a rock from the area nicknamed ‘South Séítah,’ and it all became clear: The crystals within the rock provided the smoking gun.”
The PIXL, or Planetary Instrument for X-ray Lithochemistry, uses X-rays to analyze rocks and work out what they are composed of. Using PIXL on a particular sample called “Brac” showed a distinctive structure that indicated igneous rock.
“A good geology student will tell you that such a texture indicates the rock formed when crystals grew and settled in a slowly cooling magma – for example, a thick lava flow, lava lake, or magma chamber,” said Farley.
This analysis also confirmed that the rocks had been in contact with water, adding more evidence to the assumption that the Jezero crater is the site of an ancient lake. Researchers are still debating exactly how long water was present at this site, so this finding contributes to understanding the history of the region.
“The rock was then altered by water several times, making it a treasure trove that will allow future scientists to date events in Jezero, better understand the period in which water was more common on its surface, and reveal the early history of the planet,” Farley said. “Mars Sample Return is going to have great stuff to choose from!”
One of Perseverance’s jobs is to collect samples of Martian rocks and soil and seal them into tubes for later collection by another rover and eventual return to Earth in the Mars Sample Return mission. This will allow scientists to study the samples in greater detail than is possible for a rover to do.
