(Image via astronomy.com)
Staff Writer: Akshit Bagga
Email: abagga@umassd.edu
NASA’s Curiosity rover discovered the largest organic chain molecules while exploring Mars, indicating possibility of life on the red planet. A group of scientists working with the Mars mission noticed traces of amino acids.
These organic chain molecule findings are a significant stepping stone as they open the doors to a study about life previously existing on our neighboring planet.
The organic compound was found in a 3.7-billion-year-old rock sample collected in the Yellowknife Bay region of Mars. The Yellowknife Bay is a 5-meter-deep geological depression formed by a crater and is usually referred to as the Gale crater area.
NASA’s curiosity rover landed in the 96-mile-wide Gale crater back in 2012 as part of the Mars Science Laboratory exploration mission. Tests performed on these samples onboard the curiosity rover have discovered traces of fatty acids, which link to biological activities that usually indicate living organisms.
Although the researchers haven’t ruled out the possibility of these fatty acids being formed as a result of geological processes on the planet, an expert has mentioned that this material represented the best chance that scientists ever have for identifying remains of life on Mars.
Caroline Freissinet, an astrochemist working at the Laboratoire Atmosphères et Observations Spatiales in France, said, “Our study proves that, even today, by analyzing Mars samples we could detect chemical signatures of past life, if it ever existed on Mars.”
Caroline had previously worked with the same samples and has also co-led a study about organic materials in the year 2015. “These molecules can be made by chemistry or biology”, added Caroline.
From landing in the year 2012, the Curiosity rover has covered a 20-mile area across the Gale crater. In its sixth year on Mars, it detected small organic chain molecules which later prompted scientists to explore new techniques of studying Mars ultimately leading to the latest discovery of large chain organic molecules.
Daniel Glavin, a senior scientist for sample return at the NASA’s Goddard Space Flight Center in Greenbelt, Maryland said, “There is evidence that liquid water existed in Gale Crater for millions of years and probably much longer, which means there was enough time for life-forming chemistry to happen in these crater-lake environments on Mars.”
Daniel added, “We are ready to take the next big step and bring Mars samples home to our labs to settle the debate about life on Mars.”
The discovery was unexpected since the curiosity rover was tracing for amino acids, blocks of proteins, using the Sample Analysis at Mars (SAM) equipment installed aboard the rover. Heating the sample twice in the SAM equipment, the team did not discover any amino acid but instead found versions of fatty acids.
These organic material traces were larger than usual, containing 12 consecutive carbon atoms and were like the ones found on Earth. Significant amounts of carbon based decane, undecane, and dodecane were discovered.
Suspecting that these may have been a byproduct of heating initial samples, scientists traced their experiment backwards, ultimately concluding that the mud samples from Gale Crater showed signs of fatty acids.
John Eiler, a geology and geochemistry professor at California Institute of Technology who works on analyzing the different isotopes of carbon and hydrogen in organic chemistry, said, “At present, there is no plausible path to making such measurements using an in-situ instrument on Mars. The findings reported in this paper present the best chance we have seen for identifying the remains of life on Mars.”
Eiler added, “But sealing the deal absolutely requires the return of such samples to Earth.”
We might be close, but we will need to wait a bit longer before the scientists test samples in the lab and answer, “Is life possible on Mars?”