NASA on Thursday confirmed the strongest, most direct evidence yet that water once flowed freely on the surface of Mars. "Detailed analysis and review have borne out researchers' initial interpretation of pebble-containing slabs that NASA's Mars rover Curiosity investigated last year," the space agency said. "They are part of an ancient streambed." Flowing water, scientists believe, increases the odds of an environment supporting life (as we on Earth know it). Maybe, just maybe, the people who think they see rats running around on Mars are onto something! (Just kidding. More like they're on something.) What's significant about the latest find is that the rocks are the "first ever" discovered on the Red Planet to contain streambed gravels. The rocks were found by Curiosity last fall. Examining them over time, researchers actually were able to determine how deep and fast the water flowed at that location. "At a minimum, the stream was flowing at a speed equivalent to a walking pace -- a meter, or three feet, per second -- and it was ankle-deep to hip-deep," Rebecca Williams of the Planetary Science Institute in Tucson, Arizona, said in a statement. "These conglomerates look amazingly like streambed deposits on Earth," Williams said. "Most people are familiar with rounded river pebbles. Maybe you've picked up a smoothed, round rock to skip across the water. Seeing something so familiar on another world is exciting and also gratifying." NASA puts it all in perspective:
The atmosphere of modern Mars is too thin to make a sustained stream flow of water possible, though the planet holds large quantities of water ice. Several types of evidence have indicated that ancient Mars had diverse environments with liquid water. However, none but these rocks found by Curiosity could provide the type of stream flow information published this week. Curiosity's images of conglomerate rocks indicate that atmospheric conditions at Gale Crater once enabled the flow of liquid water on the Martian surface.
This is a great step in answering the eternal question about life on Mars. From here there are two obvious avenues to pursue: 1) Drill down into the Martian soil to look for evidence of fossils, and 2) Try to figure out where those rats live. At least one of them should pay off. Now read this: