NASA’s Curiosity rover, which has been scouring Gale Crater and the slopes of Mount Sharp since 2012, has detected an important carbon signature in samples collected using its assortment of research instruments.
While the detection of this carbon signature is intriguing, it doesn’t directly point to ancient life on the Red Planet.
For this particular study, Christopher House of Pennsylvania State University led a team that used 24 different samples collected by Curiosity during its time in Gale Crater.
Each sample was placed into SAM’s ovens, where they were heated to approximately 850° Celcius — allowing gases inside the samples to release into SAM’s instruments.
Carbon is commonly considered one of the most — if not the most — important elements in life as it is currently understood and known to have evolved.
If astrobiologists and researchers can determine the types of carbon atoms present in samples that feature carbon signatures, they can gain a better understanding of what conditions the sample was exposed to before being sampled by a rover.
study, researchers found roughly half of the 24 samples contained large amounts of carbon-12 atoms — a potentially stunning discovery given carbon-12’s relationship to life on Earth.
“On Earth, processes that would produce the carbon signal we’re detecting on Mars are biological.
Mars likely formed with a different mix of carbon isotopes than Earth, and carbon could be cycling through the planet without any life interfering.
The biological hypothesis is inspired by life on Earth, with researchers hypothesizing that ancient bacteria on the Martian surface could have produced a unique carbon signature when they released methane into the atmosphere.
The first of the two nonbiological hypotheses suggests that the carbon signature in the samples could be a result of an interaction between ultraviolet light and carbon dioxide gas in the Martian atmosphere — producing new, carbon-containing molecules.
The second nonbiological hypothesis suggests that the carbon signature is the result of leftover carbon from a time when the solar system could have passed through a giant molecular cloud that was rich in the type of carbon detected in the Curiosity samples.
Data from the House et al.