NASA went a step further in its investigation into the presence of life on Mars by announcing that its Curiosity explorer robot, a mission that landed on that planet in 2012, has found organic molecules in rocks on the Martian surface."The chances of finding signs of remote life in future missions, if life was ever present on Mars, simply increased", said Curiosity project director Ashwin Vasavada on the USA agency's television channel.
A reminder: Organic molecules aren't necessarily produced by organisms; they're just chemical compounds that contain carbon. Researchers say they can't rule out a biological source.
Curiosity rover found direct evidence of water in an ancient waterbed on the Red Planet. "Whether it holds a record of ancient life, was food for life, or has existed in the absence of life, organic matter in Martian materials holds chemical clues to planetary conditions and processes". An incredible discovery because many forms of life have their origins from organic molecules.
Additionally, the molecular observations by Curiosity do not reveal the specific source of the organic compounds in the Gale Crater.
NASA's Curiosity Mars Rover snaps a self-portrait at a site called Vera Rubin Ridge on the Martian surface in February 2018 in this image obtained on June 7, 2018.
The results don't explain shorter-lived spikes in methane levels - as high as 45 parts per billion - that have been detected. The samples were collected at 5 cm depth only, at the foot of mount Sharp in the crater Gale, which is considered to be an ancient lake.
The scientists were surprised to find organic compounds, especially in the amounts detected, considering the harsh conditions, including bombardment of solar radiation on the Martian surface.
The organic matter was found in the bed of an ancient, now deceased lake on the planet, and could have formed 3 billion years ago. Scientists estimated the age of the rocks by the crater count method.
SAM found a number of compounds in the samples including sulphur, carbon, thiophenes, benzene, toluene, and small carbon chains, such as propane or butene. Mars scientists have long feared that any organics would be extremely tough to find.
There have been hints of this kind of life before (with a previous discovery of liquid water, ) but this new discovery in over three-billion-year-old sediments on Mars is said to be the most convincing evidence to date.
So, at present, this new information may not be a strong indicator of the presence of life on Mars at present, or somewhere during its past, it does provide a starting point for further Mars missions, NASA is planning on sending new Mars missions that will search for signs of life on the planet's surface and also below its surface. "But it doesn't tell us that life was there".