International Year of Astronomy.

'''The International Year of Astronomy (IYA2009) will be a global celebration of astronomy and its contributions to society and culture, highlighted by the 400th anniversary of the first use of an astronomical telescope by Galileo Galilei.'''


As APOD says, "Peering through that small window, Galileo discovered that the Moon has craters, Venus has phases, Jupiter has moons, and Saturn has rings."

There's so much we have yet to discover.