Scientists Confirm Possible Discovery of Organic Substances in Martian Rocks

Source: NASA/JPL-Caltech

There is hope that the Perseverance rover has discovered organic molecules in the Jezero Crater rocks. Organic chemicals have been detected on Mars before, according to previous investigations. There is data to support this from the Curiosity rover, the Mars Express orbiter, and the Perseverance lander. None of this requires biology as a necessary explanation; many different types of geological processes can promote carbon-based chemistry. More research into these molecules, however, might shed light on Mars’s past water availability and on the possibility that the Red Planet has ever been habitable.

The minerals were collected from two locations within the crater, and they both show signs of having been altered by water, creating ideal spaces for the synthesis of organic compounds. It’s possible they even have trace amounts of carbon-based molecules, according to one type of examination. A great deal more water used to be present in the Jezero Crater than exists there at present. On the floor of the crater, remnants of the ancient river delta can still be seen. Water-rock interactions have the potential to produce organic molecules similar to those discovered in the ancient delta.

The question of whether or whether there are further organic substances on the crater bottom remains unanswered. The majority of the rock found within the crater was unexpectedly volcanic, rather than sedimentary, as opposed to the majority of scientists’ expectations. The igneous rocks on the crater floor were probed by an international team lead by planetary scientist Eva Scheller of Caltech and MIT using the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument on board Perseverance.

They examined three rocks from two locations within the crater using deep ultraviolet Raman and fluorescence spectroscopy, and discovered evidence that the materials had been significantly changed by contact with water. The existence of two unique alterations hinted at two separate aquatic habitats that existed at various points in time in the distant past. First, between 3.8 and 2.7 billion years ago, carbonates formed in olivine-rich igneous rock through interactions with liquid water.

Sulfate-perchlorate (salt) mixtures may have formed in the rocks due to the intrusion of salty brackish water sometime between 2.6 and 2.3 billion years ago. Carbonates and perchlorates are formed in the same way, by water penetrating rocks and carrying dissolved minerals to crevices where they are deposited. Perchlorates are rapidly dissolved by water, thus it’s doubtful that the rocks have been exposed to it since they were deposited. The group discovered fluorescence evidence indicative of aromatic chemical substances like benzene in all three rocks. According to the researchers, these are stored in minerals associated with both aquatic settings, however we do not yet know what these minerals are.

Susan Kowal
Susan Kowal is a serial entrepreneur, angel investor/advisor, and health enthusiast.