We humans have been busy lately... there are a lot of spacecraft buzzing around the solar system. Sure, you've heard of Cassini, and the Mars probes, but there are two very interesting spacecraft making two very interesting encounters in the next few weeks.
1) On June 27, NASA's Deep Impact spacecraft -- which sent a chunk of copper smashing into a comet back in 2005, and which has now been repurposed for planetary science -- will swing by the Earth, using our planet's gravity to change its direction and speed. DI will pass at a distance of just 37,000 km (23,000 miles)! That's around the same height above the surface as geosynchronous (i.e. weather and communication) satellites. This maneuver will send the little spacecraft on its way to an encounter with the comet Hartley 2 in November.
2) The European Space Agency's amazing Rosetta spacecraft will fly by the asteroid 21 Lutetia on July 10. The asteroid is about 95 km across (60 miles), and the flyby distance will be about 3200 km (2000 miles). That's pretty close, certainly near enough to provide some nice images of the rock. In 2008, Rosetta passed the smaller asteroid 2867 Steins and returned nice images, and in 2009 swung by the Earth, sending back an image so heart-achingly beautiful I chose it as one of my Top Ten images of the year.
Rosetta's primary mission is taking it to the comet 67P/Churyumov-Gerasimenko, where it will drop an actual honest-to-FSM lander on the comet's surface! This is a tremendously exciting mission, and I can't wait to see what new wonders it will send us.
Tip o' the Whipple Shield to Emily Lakdawalla for the Rosetta news.