Published in The Hindu on March 28, 2013
In what counts for one more extraordinary achievement in space science, the Mars Curiosity rover launched by NASA scientists has found strong evidence of habitable conditions that once existed at the Yellowknife Bay area in Gale crater. These reconfirm that certain regions on Mars have had favourable conditions that could have supported life some three billion to four billion years ago. This is a step closer to discovering the Holy Grail — a planet capable of supporting life. A week ago, the rover’s mast camera found evidence of water-bearing minerals in veins that cut across the Knorr rock at several places. The finding comes close on the heels of the March 12 major discovery of smectite clay mineral by chemical analysis of a John Klein rock specimen drilled by the rover. The presence of smectite clay, which constitutes nearly 20 per cent of the sample analysed, is a definite indicator of the presence of liquid water on Mars long ago. The chemical analysis revealed many other details of the paleo-environment. For instance, the absence of abundant salt suggests “a fresh-water environment,” and the presence of calcium sulphate reinforces the non-acidic depositional conditions. The John Klein rock did reveal certain clues even prior to drilling. The rock was grey and the powdered sample had the same colour. Together, they indicate the absence of iron compounds, and hence the non-acidic depositional environment. The discovery of other elements — sulphur, nitrogen, hydrogen, oxygen, phosphorus and carbon — through chemical analysis reinforces the possibility that the planet could have harboured life. After all, these elements are considered the “key chemical ingredients for life.” Chemical analysis of another rock sample that will be soon drilled will confirm these findings.
Mars is today a cold and dry place and has conditions that are decidedly hostile to life. Even if slim, the possibility that Mars once harboured life cannot be ruled out, particularly after the latest discoveries. Behind this achievement are a series of firsts and remarkable technological milestones. The safe landing of the rover, a self-contained science laboratory on six wheels, using an “outlandish” design was the first. But by drilling into Martian rock to collect a sample, Curiosity became the first rover ever to fructify the ideas that were once in the realm of science fiction. Together with its ability to grind and sieve the sample before chemically analysing it using a suite of advanced instruments, the discoveries it has made so far underline how far we have come in using technology for studying the wider universe of which we are but a small part.