Organic Molecules Discovered By Curiosity Rover Consistent With Early Life On Mars, Study Finds

Organic compounds called thiophenes were recently discovered on Mars, and a new study published in the journal Astrobiology thinks their presence would be consistent with the presence of early life on Mars. Phys.Org reports: “We identified several biological pathways for thiophenes that seem more likely than chemical ones, but we still need proof,” Washington State University astrobiologist Dirk Schulze-Makuch said. “If you find thiophenes on Earth, then you would think they are biological, but on Mars, of course, the bar to prove that has to be quite a bit higher.” Thiophene molecules have four carbon atoms and a sulfur atom arranged in a ring, and both carbon and sulfur, are bio-essential elements. Yet Schulze-Makuch and Heinz could not exclude non-biological processes leading to the existence of these compounds on Mars. Meteor impacts provide one possible abiotic explanation. Thiophenes can also be created through thermochemical sulfate reduction, a process that involves a set of compounds being heated to 248 degrees Fahrenheit (120 degrees Celsius) or more. In the biological scenario, bacteria, which may have existed more than three billion years ago when Mars was warmer and wetter, could have facilitated a sulfate reduction process that results in thiophenes. There are also other pathways where the thiophenes themselves are broken down by bacteria.