Perseverance may have found evidence of organic compounds within the rocks of Jezero Crater.
Previous research has shown evidence of organic compounds in Mars. The Curiosity RoverAnd the Mars ExpressAs evidence, orbiter also returned evidence. Data from Perseverance. None of it necessarily implies some kind of biology – a variety of geological phenomena can facilitate carbon-based chemistry, after all.
These compounds can be studied in more detail to reveal more about the water history. MarsIt is also possible that the Red Planet has hosted some living organisms at least once.
Two different sites within the crater were used to obtain the minerals. The evidence shows that aquatic processes created tiny cavities for organic chemistry. One analysis suggests that they might even contain carbon-based compounds.
Many eons ago the Jezero Crater was much more humid than it is now. You can still see traces of the ancient river deltaOnce, they were scattered across the crater floor. Water and rock interactions can lead to the formation organic compounds similar to the ones found. In the ancient delta.
It is unknown if there are any organic compounds on the crater floor. Scientists expected that the rock found therein would largely be sedimentary, deposited by water long ago – but, when Perseverance arrived, we learnt that much of the crater floor was volcanic, not sedimentary.
An international team of scientists led by Eva Scheller, Caltech and MIT carried out a survey of the crater floor’s igneous rocks using Perseverance’s Scanning Habitable Environments With Raman and Luminescence For Organics and Chemicals(SHERLOC).
They carried out deep ultraviolet Raman analysis and fluorescence-spectroscopy of three rocks taken from two different locations within the crater. They found evidence that the rocks had been in significant contact with water.
Evidence was found for two types of alteration. This suggests two distinct aqueous environments at different times in distant history.
The formation of carbonates from igneous rock rich in olivine was first caused by reactions with liquid water.
The formation of salt-perchlorate or sulfate (salt) mixtures in rocks could have occurred later, sometime between 2.6 and 2.3 billion Years ago.
Both perchlorates and carbonates need water to penetrate the rocks and dissolve and deposit minerals in hollows created by water erosion. Perchlorates easily dissolve so it’s unlikely water has reached the rocks since they were laid.
The team discovered fluorescence signatures in all three rocks. AromatherapyOrganic compounds that are similar to benzene. Researchers believe that these compounds are preserved in minerals which are related to both aqueous and aqueous environments. However, we don’t know what they might be.
“Collectively the data indicate that Perseverance’s drilled samples taken from Jezero crater’s floor show evidence for carbonation, formation of sulfurates and perchlorates.” They write in their paper.
“Fluorescence signatures consistent to organics found within these materials indicate an interplay among igneous rocks and aqueous altation.”
Since then, persistence has moved on from the data collection sites. It also took samples of the rocks, in case they were still useful. You are ferried back to EarthLater, a mission has not yet been launched.
“I hope these samples can be returned to Earth one day so that we can see the evidence of water, possibly organic matter, and discover if the conditions were right in the early history Mars.” says geochemist Mark SephtonImperial College London, UK
It will take some time before we get the confirmation we desire. However, if we can get those rocks into an Earth lab equipped with the equipment to study the compounds in detail, it could reveal more about Mars’ past habitability or non-habitability.
Perseverance will continue its slow perusal at the Jezero Crater and may find some more clues.
We will just have to watch and wait.
The research was published in Science.
