Many outlets are reporting on the recently released results of the various experiments and observations of NASA's Mars Phoenix Lander. Most notable is the discovery of nighttime snowfall
on the planet, lending credibility to the idea of a hypothesized active water cycle based on earlier data collection. "The papers rely on evidence from a variety of the instruments on the lander, and the description of the data provides an impressive catalog of the various ways that Phoenix could prod and query the Martian pole. In the months before Martian winter shut the lander down, it managed to dig a dozen trenches, taking soil samples from each. These samples went into wet and dry chemistry labs, had their conductivity tested, and were even examined using an atomic force microscope. Meanwhile, cameras and a LIDAR system (a laser-based range detector) scanned the surroundings. The overall conclusion is that the northern pole has an active water cycle. This had been suggested by a variety of evidence from orbital sensors, as well early images returned from Phoenix. It's also not a huge shock, given the seasonal growth and retreat of the polar ice cap. Still, Phoenix provided some significant details on the cycling of water in the area where it landed."