The Planetary Science Division of NASA’s Science Mission Directorate is sponsoring the Year of the Solar System! The Year of the Solar System, which actually lasts for one Mars year (or 23 Earth months), celebrates the amazing planetary science exploration activity taking place within NASA from October 2010 until August 2012. During the Year of the Solar System, the Planetary Science Division will see the arrival of the Dawn mission at the asteroid 4 Vesta and the launch of a multitude of planetary science missions including Juno (to Jupiter), Mars Science Laboratory, and GRAIL (Gravity Recovery and Interior Laboratory; to the Moon). Each month of the Year of the Solar System focuses on a different topic, and the topic for July 2011 is Asteroids: Leftovers from Planet Building. You can read about the basics of asteroids, find fun and educational activities related to asteroids and learn what NASA missions are discovering about asteroids at the Year of the Solar System website.