Rock samples collected from Mars by NASA’s Curiosity rover show signs of key ingredients for life, similar to those found on Earth.
As reported by NASAthe rover drilled samples from Gale Crater — an ancient lake on Mars and using these samples, they were able to, for the first time, measure the total amount of organic carbon in Martian rocks.
Organic carbon that’s connected to a hydrogen atom is a prerequisite for organic molecules created and used by all known forms of life. However, organic carbon can also originate from non-living sources such as volcanic eruptions or even meteorites.
Studies in the past have detected organic carbon in smaller quantities in martian rock samples, however, the novel discovery offers a glimpse into the total amount of carbon in organic compounds.
Jennifer Stern, the lead author of the study and a space scientist at NASA’s Goddard Space Flight Centre in Greenbelt, Maryland, said in the statement, “Total organic carbon is one of several measurements [or indices] that help us understand how much material is available as feedstock for prebiotic chemistry and potentially biology.”
Stern added, “We found at least 200 to 273 parts per million of organic carbon. This is comparable to or even more than the amount found in rocks in very low-life places on Earth, such as parts of the Atacama Desert in South America, and more than has been detected in Mars meteorites.”
Scientists are of the opinion that the sediment was formed via the physical and chemical weathering of volcanic rocks before it settled to the bottom of the lake.
The rover analysed the fragments using its Sample Analysis at Mars Instrument which makes use of oxygen and high heat to turn the organic carbon samples into CO2. And from the CO2 produced the instrument figures out how much organic sample was in the sample, telling the exact isotope ratio, which allows the scientists to better understand the source of carbon.
Stern further stated that the isotopic composition can only tell us what portion of the total carbon is organic carbon and what portion is mineral carbon, “While biology cannot be completely ruled out, isotopes cannot really be used to support a biological origin for this carbon, either, because the range overlaps with igneous (volcanic) carbon and meteoritic organic material, which are most likely to be the source of this organic carbon.”
She concluded by stating that in addition to organic carbon, researchers identified other signs suggesting Gale crater may have once supported life, including the presence of chemical energy sources and chemical compounds like nitrogen, sulphur, oxygen etc and the location would have offered a habitable environment for life if it ever existed there.