Slashdot Mirror
Rover Finds Ancient Streambed On Martian Surface
sighted writes "NASA reports that its Curiosity rover mission has found evidence that a stream once ran vigorously — and for a sustained amount of time — across the area on Mars where the rover is driving. There is, of course, earlier evidence for the presence of water on Mars, but NASA says this evidence, images of rocks containing ancient streambed gravels, is the first of its kind."
Hydrogen is the most abundant element in the universe and Oxygen is the third most abundant element in the universe. The only thing splitting them is Helium which is inert. All other things being equal the likelihood that a particular liquid at 'reasonable temperatures' is water is orders of magnitude more likely to be water than mercury or bromine.
It's called soil. Dirt is the stuff stuck on the bottom of your shoes.
"Remnants of Ancient Streambed on Mars NASA's Curiosity rover found evidence for an ancient, flowing stream on Mars at a few sites, including the rock outcrop pictured here, which the science team has named "Hottah" after Hottah Lake in Canada’s Northwest Territories. It may look like a broken sidewalk, but this geological feature on Mars is actually exposed bedrock made up of smaller fragments cemented together, or what geologists call a sedimentary conglomerate. Scientists theorize that the bedrock was disrupted in the past, giving it the titled angle, most likely via impacts from meteorites. The key evidence for the ancient stream comes from the size and rounded shape of the gravel in and around the bedrock. Hottah has pieces of gravel embedded in it, called clasts, up to a couple inches (few centimeters) in size and located within a matrix of sand-sized material. Some of the clasts are round in shape, leading the science team to conclude they were transported by a vigorous flow of water. The grains are too large to have been moved by wind. A close-up view of Hottah reveals more details of the outcrop. Broken surfaces of the outcrop have rounded, gravel clasts, such as the one circled in white, which is about 1.2 inches (3 centimeters) across. Erosion of the outcrop results in gravel clasts that protrude from the outcrop and ultimately fall onto the ground, creating the gravel pile at left. This image mosaic was taken by Curiosity's 100-millimeter Mastcam telephoto lens on its 39th Martian day, or sol, ..."
First, water is required for life as we know it, but the presence of water is no guarantee for life. Second, this is not a mission to determine if there are traces of life or not. Curiosity is mostly a geological mission, with an emphasis of finding out if there were ever conditions suitable to sustain life as we know it That's not anywhere near the same thing as finding proof there ever was or even if there still is life on Mars.
"Curiosity’s primary mission will be to gather geological and environmental data from the Martian surface to determine whether the planet has ever offered environmental conditions favorable for life --and collect data for a manned mission. It will do this by travelling around a particularly promising site called Gale Crater, which has three miles of exposed geological strata, or rock layers like we have in the Grand Canyon. By drilling into these rocks and sampling them, scientists can tell quite a bit about global processes that formed the planet --including the role of water in its creation and the possibility of microbial life." http://energy.gov/articles/powering-curiosity-lab-tech-goes-mars