Happy birthday Envisat

On March 1 2002, the European Space Agency sent into space the world's largest Earth observation satellite, Envisat. In the last decade, the eight-ton satellite circled the Earth more than 50 000 times. This shot taken last month by Envisat shows a rare view of Italy: almost all of the country is covered with snow.

But Envisat is just one of dozens of probes already aloft-or planned for launch into-space to further science's knowledge of the Earth, the Sun, and the rest of our solar system.