Explainer: Mars rover discovers building blocks of life on the red planet

Explainer: Mars rover discovers building blocks of life on the red planet

Mars Curiosity Rover found "building blocks for life" on Mars, which are, according to the USA space agency, a complex organic matter in the rocks on the surface of Mars. "Curiosity has shown that Gale Crater was habitable around 3.5 billion years ago, with conditions comparable to those on the early Earth, where life evolved around that time". The discovery is said to be the most compelling evidence that billions of years ago, the parched Red Planet once consisted of carbon-based compounds essential to sustain life.

Additional data from the robotic probe confirms the detection of "seasonal patterns" in methane levels, NASA geophysicist Ashwin Vasvada said in the live-streamed announcement.

The new observations have increased the inventory of known Mars organics and "are more consistent with what we would expect if the organics were from life, from meteorites or from geological processes", Eigenbrode added.

Arriving at Mars in 2012 with a drill and its own onboard labs, Curiosity confirmed the presence of organics in rocks in 2013, but the molecules weren't exactly what scientists expected. "The question of whether life might have originated or existed on Mars is a lot more opportune now that we know that organic molecules were present on its surface at that time".

In a second paper in Science, NASA's Christopher Webster and an worldwide team describe how they have used instruments on-board Curiosity to measure a seasonal variation in methane levels in the Martian atmosphere.

This is not the first time that Curiosity has detected organic molecules, but previous measurements were considered unreliable because of possible sample contamination and unwanted chemical reactions.

In addition to finding organic molecules in the rocks in Gale Crater, rover scientists are reporting another intriguing finding. "That gives me great hope because we can perhaps get past these surface environments that are so harsh and maybe [go] a little deeper and find better-preserved materials". However, "we're in a really good position to move forward looking for signs of life", says Jennifer Eigenbrode, NASA biogeochemist and lead author of the study published in the journal Science. For what was said detected molecule is unknown. Given that here on Earth, methane is largely created by plants and animals, some scientists are suggesting this means the same can be said for the methane on Mars, although it can also be produced by non-biological processes too.

Jen Eigenbrode, the research scientist at Goddard who investigates gases and other organic molecules.

To determine whether the methane is biological, Webster said, scientists can weigh the kinds of carbon atoms it contains (life prefers the lighter versions).