Scientists classify comets and asteroids that pass within 28 million miles of Earths orbit as near-Earth objects (NEOs). Asteroids that collide and break into smaller fragments are the source of most NEOs, and the resulting fragments bombard the Earth at the rate of over 100 tons a day. Although the vast majority of NEOs that enter Earths atmosphere disintegrate before reaching the surface, those larger than 100 meters (328 feet) may survive the descent and cause destruction in and around their impact sites. Furthermore, even smaller objects that disintegrate before reaching Earths surface can cause significant damage. This book examines NASAs NEO Program and assesses the Agencys progress toward meeting statutory and other Program goals. Specifically, it reviews NASAs allocation and use of resources and plans for the future of the Program.