After analysing rock samples collected by the Curiosity Rover, NASA has made an exciting discovery: Conditions on a newly discovered grey (instead of red) part of Mars show it had conditions that "once were favourable for life". It's an incredible breakthrough.
The excitement stems from new samples that have been found to contain sulphur, nitrogen, hydrogen, oxygen, phosphorus and carbon. Curiosity pulled out of a new site, a few hundred metres away from where it had drilled late last year, and the elements found within are some of the key building blocks of life.
The nerd breakdown of why this could mean life was on Mars is complicated, but here's a simple version: The sample NASA analysed contained clay minerals. Those minerals would have been created by fresh water (they were collected from a stream bed) reacting to igneous rock also found in the sample. The resulting minerals were a mix of oxidised, less-oxidised and non-oxidised. This suggests to Paul Mahaffy, principal investigator of the Sample Analysis at Mars, that they could have been "a possible chemical energy source for micro-organisms".
So life-sustaining conditions seem to be pinned to the partially oxidised sediments of this ancient "grey Mars". In fact, the simple act of sustaining life could have changed the colour of martian rock from red to grey. That is fascinating. Further investigation could provide even more information about habitable conditions:
Scientists plan to work with Curiosity in the "Yellowknife Bay" area for many more weeks before beginning a long drive to Gale Crater's central mound, Mount Sharp. Investigating the stack of layers exposed on Mount Sharp, where clay minerals and sulfate minerals have been identified from orbit, may add information about the duration and diversity of habitable conditions.
Microbial life isn't as exciting as comic book Martians, but this is deeply exciting anyway. The universe is impossibly vast, and science is telling us that we have found conditions once suitable to life RIGHT NEXT DOOR? That is incredible. [NASA]