NASA's Curiosity Rover had discovered a sudden spike in the atmospheric methane level on Mars last week. As methane emissions are associated with living beings on Earth, this discovery made many believe that alien life forms, at least in its simplest form might be thriving on the Red Planet. Interestingly, when NASA again tested the spike in methane emission a day back, it had astonishingly disappeared, dropping to less than 1 part per billion by volume detected.

In a recent statement, NASA revealed that the methane emission center discovered by Curiosity Rover was one of the transient methane plumes that have been observed in the past. Several previous studies have shown a rise and fall of methane levels in the Mars seasonally, but until now, experts at NASA haven't found a pattern in the occurrence of these transient plumes.

"The methane mystery continues. We're more motivated than ever to keep measuring and put our brains together to figure out how methane behaves in the Martian atmosphere," said Ashwin Vasavada, Curiosity's project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California in a statement.

Another top expert at NASA revealed that it is practically impossible to determine whether these methane plumes are the result of biological or geological causes.

"With our current measurements, we have no way of telling if the methane source is biology or geology, or even ancient or modern," said Paul Mahaffy, a researcher at the NASA's Goddard Spaceflight Center in Greenbelt.

A few weeks back, another study led by an Indian scientist named Regina Dass of the Department of Microbiology, School of Life Sciences, Pondicherry had claimed that some of the photos taken by the Curiosity Rover featured alien algae and fungi in them. The research also suggested that these photographs are authentic proof of alien creatures thriving on the Red Planet.