While space exploration of Mars tends to get the lion's share of media attention, I'm riveted by the news that NASA's Messenger spacecraft has detected strong evidence that the planet Mercury harbours water ice at its poles, and possibly even organic matter. It seems hard to believe that a planet with temperatures that can reach nearly 500 degrees Celsius could have ice anywhere, but Mercury's poles get very little exposure to the sun so temperatures are much, much lower. Apparently the shade of deep craters also helps preserve the ice.
As we learn more about our solar system, it seems more and more likely that we'll find extraterrestrial life somewhere within Sol's orbit - probably only microbes, but even that would be a stunning new paradigm for human beings to accept. I am profoundly grateful to live in an era when humanity's best and brightest are discovering so many new wonders.