If the latest analysis of the data provided by Curiosity Rover's samples of the Martian atmosphere is anything to go by, life may have existed on the Red Planet more than 4 billion years ago.
The newest investigation reveals that Mars lost its oxygen four billion years ago, probably after it collided with an object, purportedly as big as Pluto.
The Curiosity rover landed on Mars a year ago. It has returned its first measurements of the makeup of gases, including argon, oxygen, nitrogen, carbon monoxide and carbon dioxide in the atmosphere of the Red Planet.
"This data is clear evidence of a substantially thicker atmosphere, hence a warmer and wetter Mars in the past than the cold and arid planet we find today," said Sushil Atreya, professor of atmospheric, oceanic and space sciences at the University of Michigan.
The team of scientists, including an Indian-origin researcher, is working on Curiosity's Sample Analysis at Mars (SAM). After scrutinizing the data, they stated that the calamitous collision completed obliterated the oxygen-rich atmosphere, and left behind a thick blanket of carbon dioxide.
“Our Curiosity measurements are – for the first time – accurate enough to make direct comparisons with measurements done on Earth on meteorites using sophisticated large instrumentation that gives high accuracy results,” said Dr Chris Webster at Nasa’s Jet Propulsion Laboratory in Pasadena.
The team arrived at the conclusions after measuring different gases and isotopes in samples of Martian air. The measurements established that heavy isotopes of carbon and oxygen were plentiful today vis-à-vis the proportions in the raw material that formed the planet.
"As atmosphere was lost, the signature of the process was embedded in the isotopic ratio," Paul Mahaffy of NASA Goddard Space Flight Center, Greenbelt and principal investigator for SAM said, explaining the phenomenon.
The presence of heavier isotopes in carbon dioxide gas suggests that Mars lost its atmosphere from the top and not from the lower end adjacent to the ground.
The MAVEN mission, scheduled to be launched in November of 2013, will measure the rate at which Mars is currently losing its atmosphere.
The latest set of information will enable scientist better understand when and how the atmospheric conditions on the Martian surface changed and whether the Red Planet ever had conditions propitious for life.
The findings have been published in the journal Science