Phoenix Lander Watches Snow Falling on MarsSAs the clock continues to tick for brave Phoenix so far away on Mars, the discoveries keep on rolling: this time, that snow falls on Mars. A laser instrument called for pulsing the atmosphere and observing what gets bounced back detected Martian flurries at altitudes of 4km in the clouds. The snow is vaporizing before hitting the ground, but the discovery lends some crucial insight into the Martian water cycle. As did another juicy finding dug up from the soil. The latest sample from the extended surface digs to hit Phoenix's Easybake detected the presence of calcium carbonate-a mineral found in chalk and clay that tends to only exist in soil after interactions with liquid water. Phoenix has already tasted water ice from its landing point on the North Pole, but the carbonate is an important find for suggesting more watery interactions in the past. The sun is slowly setting on Phoenix as winter sets in-its solar panels output less juice every day. But before going cold completely, the team hopes to fire up a microphone (the guy has everything) to take a listen for whatever might be out there. [NASA, Mars Phoenix Twitter, image, of course, simulated]