- February 14
- Stardust few past Comet Tempel-1. It reexamined the damage inflicted by Deep Impact in 2005 and measured how the comet has changed since then.
- March 18
- Messenger entered orbit around Mercury. Over the following 12 months, it will map the entire surface from low altitudes.
- May 19
- Space shuttle Endeavour delivered Alpha Magnetic Spectrometer-2, a giant magnet designed to hunt for antimatter and dark matter and study cosmic rays, to the International Space Station.
- July 16
- The Dawn spacecraft entered orbit around the asteroid Vesta, one of the biggest of the solar system’s leftovers. Dawn will orbit Vesta for about a year, then leave orbit, cross the asteroid belt, and enter orbit around the largest asteroid, Ceres.
- September 8
- GRAIL (Gravity Recovery and Interior Laboratory) will launch toward the Moon from Cape Canaveral, Florida.
- November 25
- The launch window opens for Curiosity, the next Mars rover.
