Life on Mars? NASA’s Curiosity Rover Finds Strongest Evidence Yet
A bonanza of organic compounds and seasonal fluctuations of atmospheric methane are detected by NASA’s Curiosity Mars rover on the surface of Mars. This marks a strong evidence that Mars may have harboured life. But the emphasis of National Aeronautics and Space Administration scientists is that there could be nonbiological explanations for these discoveries made by the rover at a site called Gale Crater.
When the rover dug just 2 inches (5 cm) into roughly 3.5 billion-year-old mudstone, a fine-grained sedimentary rock, 3 various types of organic molecules were discovered. Large seasonal cycle in the low levels of atmospheric methane was also measured. In Earth’s atmosphere, 95% of the methane is produced from biological activity but it is too soon to declare that the Martian methane is also related to life.
In 2014, the rover made the first definitive detection of organic molecules at the same place, Gale Crater, but it was a much more limited set of compounds. In the northern hemisphere, at the end of summer, the amount of methane peaked at about 2.7 times the level of the lowest seasonal amount.
Astrobiologist Jennifer Eigenbrode of NASA‘s Goddard Space Flight Center in Maryland said, “There’s three possible sources for the organic material. The first one would be life, which we don’t know about. The second would be meteorites. And the last one is geological processes, meaning the rock-forming processes themselves.”
Christopher Webster, an atmospheric science research fellow at NASA’s Jet Propulsion Laboratory in California, said it is possible that existing microbes are contributing to the Martian atmospheric methane and further added, “With this new data, we again cannot rule out microbial activity as a potential source.“
Considering the harsh conditions, including bombardment of solar radiation on the Martian surface, scientists were surprised to find organic compounds, especially in the amounts detected. After drilling, rover heats the rock samples and releases the compounds. The findings of organic compounds and methane hint at an earlier time on Mars when water was present and the existence of primitive life forms was possible.
Scientists hope to find better preserved organic compounds with Curiosity or other rovers that would allow them to check for chemical signatures of life. The research study was published in the journal Science.