The Perseverance rover has made some exciting discoveries at the location it explores on Mars, the Jezero Crater, helping scientists better understand this region and its geological history.
Two major discoveries are that the rocks of the Jezero crater have been in the presence of water on several occasions and that some contain organic molecules. These organic molecules can be created by biological or non-biological processes, so they do not confirm the existence of life there, but they are a good sign that if there had ever been life there, it should be possible to find proof of this.
Additionally, the team discovered that the rocks in the crater are igneous, having formed from lava or magma flows. This answers a major question about the composition of the crater, as previously researchers were unsure whether the rocks there were igneous or sedimentary.
“I was starting to despair that we would never find the answer,” said Ken Farley, scientist with Caltech’s Perseverance Project in a declaration. “But then our PIXL instrument did take a good look at the abraded area of a boulder in the area nicknamed ‘South Séítah’, and it all became clear: the crystals inside the boulder provided the smoking gun. “
PIXL, or Planetary Instrument for X-ray Lithochemistry, uses X-rays to analyze rocks and determine what they are made of. Using PIXL on a particular specimen called “Brac” showed a distinctive structure that indicated igneous rock.
“A good geology student will tell you that such a texture indicates that rock formed when crystals grew and settled in slowly cooling magma – for example, a thick lava flow, a lake of lava or a magma chamber, ”said Farley.
This analysis also confirmed that the rocks had been in contact with water, adding more evidence to the hypothesis that Jezero Crater is the site of an ancient lake. Researchers are still debating the exact duration of the presence of water at this site. This discovery therefore contributes to understanding the history of the region.
“The rock was then repeatedly weathered by water, making it a treasure that will allow future scientists to date the events of Jezero, to better understand the period when water was more common on its surface,” and reveal the ancient history of the planet, ”said Farley. “Mars Sample Return is going to have an excellent choice! “
One of the tasks of Perseverance is to collect samples of Martian rocks and soil and seal them in tubes for later collection by another rover and possible return to Earth as part of the Mars Sample Return mission. This will allow scientists to study the samples in more detail than a rover could.