Scientists have found new information that might rekindle the hypothesis of life on the red planet: spikes in Martian methane. The Curiosity Rover recorded an enormous spike which peaked for two months and then disappeared. The newest theory is that such increases in methane levels might be explained by the presence of biological organisms: bacteria, scientists say, could be responsible for such sudden increases.
Previous investigations revealed that the Red Planet was once the home of liquid water on its surface, but definitive proof of life had not been discovered. The Curiosity Rover’s readings are consistent with other observations, which detected out-of-the ordinary methane increases on the plane. The difference, however, is that the spikes measured at Gale Crater represented a 10-fold increase over the background methane levels present in the Crater.
These methane levels were measured with the help of TLS: the Curiosity Rover’s Tunable Laser Spectrometer. Such a delicate instrument uses intense light when analyzing the concentrations of specific chemicals. Sequential measurements were carried out by the spectrometer and each time, methane levels soared from a level of .69 parts per billion by volume to an astonishing 7.2 parts per billion by volume. All these spikes could be detected over an area of approximately 300 meters, 1 kilometer away from the area where lower readings had been recorded.
According to Chris Webster, lead author of the study published in Science, working at the Jet Propulsion Laboratory at NASA, methane-belching bacteria can’t be ruled out as the source of the methane spike. There are, however, many other plausible theories that could explain such spikes. On Earth, the sun contributes to methane level increases by degrading organic material let behind by meteors. This couldn’t have been the case on Mars, as it would have required a recent impact. Whether biogenic or geophysical, scientists have to determine the exact cause of the methane increases.
“The persistence of the high methane values over 60 sols (Martian days) and their sudden drop 47 sols later is not consistent with a well-mixed event, but rather with a local production or venting that, once terminated, disperses quickly.”
the scientists wrote in the study.
Gale Crater owes its existence to a large meteor that struck Mars approximately 3.5 billion years ago. According to the team of scientists, which measured methane levels for more than one full Mars year, the gas is continuously created on the Red Planet by a multitude of mechanisms. They have to analyze whether these spikes could be explained by past reservoirs releasing build-up methane levels.
Image Source: Space 4 Case