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NASA’s Perseverance Rover has been on Mars for 10 months and scientific results are pouring in. Among them, and the most exciting one presented at the American Geophysical Union fall science meeting in New Orleans, is the discovery of organic molecules in the Jezero Crater.
Organics on Mars have been observed before so the news is not revolutionary, but the fact that they keep getting found in locations at huge distances from one another suggests that finding these kinds of molecules might be common across the planet.
The discovery of organic compounds was possible thanks to the SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) instrument. SHERLOC found organics inside rocks as well as on their dusty surface. Another indication that organic molecules are common.
“Curiosity also discovered organics at its landing site within Gale Crater,” Luther Beegle, SHERLOC principal investigator at NASA’s Jet Propulsion Laboratory, said in a statement. “What SHERLOC adds to the story is its capability to map the spatial distribution of organics inside rocks and relate those organics to minerals found there. This helps us understand the environment in which the organics formed. More analysis needs to be done to determine the method of production for the identified organics.”
Organics on Earth are predominantly the product of living organisms' processes. However, plenty of chemical reactions that don’t require life can produce organic molecules. So, finding these doesn’t mean finding evidence that life once existed (or maybe still does) on Mars. To better answer that, Perseverance has collected samples to be launched from Mars back to Earth.
“This is a question that may not be solved until the samples are returned to Earth, but the preservation of organics is very exciting. When these samples are returned to Earth, they will be a source of scientific inquiry and discovery for many years,” Beegle explained.
The industrious rover has also been mapping what's beneath the crater, thanks to its ground-penetrating radar. It showed that some rock formations that the rover investigated extended deep underground. What's more, they were stretching into the soil at the same angle seen above ground. This and more provided insights into the comparative ages of rocks around Perseverance.
A final exciting result from the presentation centered around the nature of the bedrock. One rock of particular interest appeared to be composed of an unusual abundance of large olivine crystals engulfed in pyroxene crystals.
“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. “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. Mars Sample Return is going to have great stuff to choose from!”
