On 27 September, NASA announced that the Mars Curiosity rover found evidence of an ancient stream bed near the north rim of the Gale Crater. This is the first evidence of water on Mars that includes images of gravel, and while small stones may hold no importance for we non-geologist types, it’s Christmas for the scientists who have been studying these ancient streams.
NASA’s latest Mars rover was launched on 26 November 2011 and made its landing on the red planet on 6 August of this year. Constructed at the Jet Propulsion Laboratories in California, it is the largest rover ever launched. Essentially, it is a mobile laboratory, equipped to scope things out, pick things up, take good footage, and (perhaps most importantly) navigate Mars’ rough terrain with minimal damage. The NASA fact sheet on the mission states that “the overarching science goal of the mission is to assess whether the landing area has ever had or still has environmental conditions favourable to microbial life.” Having only been on Mars for two months out of its two-year mission, Curiosity has already collected information towards determining the answer to this goal.
These riverbed sediments were discovered in the Hottah outcrop, which under examination turned out to be a conglomerate. Conglomerates are only formed when rounded stones are washed together by a stream or wave, then cemented by sandy or clay matrix. The presence of Hottah strongly indicates that it marks the spot of once swiftly running water. The size and shape of gravel have also given clues as to how fast, deep, and far this river ran. According to Curiosity scientist William Dietrich of the University of California at Berkeley, “we can interpret the water was moving about three feet per second, with a depth of somewhere between ankle and hip deep.” The roundness of the gravel also indicates these rocks travelled very far.
Curiosity is making news in the space-exploration world almost every week. From little things like checking in on Foursquare to fairly significant things like the riverbed at the Hottah outcrop, this rover is already marking itself out as one of the mascots of this scientific generation. The little pieces of information the rover gathers every single day are slowly building a better picture of the history of Mars. Though it is far-fetched to expect that Curiosity will uncover information that will change our ideas about the universe as we know it, the looming possibility is still intriguing. Until then, Curiosity will continue to rove, NASA will still watch the stars, and geologists will stare at gravel.
PHOTO CREDIT: tjblackwell.co.uk