Stony asteroids with a diameter of 4 meters (13 ft) impact Earth approximately once per year.  Asteroids with a diameter of roughly 7 meters enter Earth's atmosphere with as much energy as Little Boy (the atomic bomb dropped on Hiroshima , approximately 15 kilotonnes of TNT) about every 5 years.  These ordinarily explode in the upper atmosphere , and most or all of the solids are vaporized .  Every 2,000–3,000 years, objects produce explosions of 10 megatons comparable to the one observed at Tunguska in 1908.  Objects with a diameter of one kilometer hit the Earth an average of twice every million years.  Large collisions with five kilometer objects happen approximately once every twenty million years. 
The Catalina Sky Survey is not alone. In Hawaii, the Pan-Starrs 1 telescope is also actively involved with near-Earth object discovery, as are the Darpa Space Surveillance Telescope and NEOWISE, a study using the Wide-Field Infrared Survey Explorer spacecraft. Additionally, the Lincoln near-Earth asteroid Research project has been a collaboration between the . Air Force, NASA, and the Massachusetts Institute of Technology. Like the Catalina Survey, the Spacewatch program is hosted at the University of Arizona and uses two telescopes on Kitt Peak, Arizona, to help survey near-Earth objects. The NEOWISE survey, headed by planetary scientist Amy Mainzer at JPL, has been very productive, detecting more than 400 near-Earth objects in a relatively short period, including some 170 discoveries. Mainzer also leads a team that has proposed NEOCam, a space-based infrared telescope designed to discover and characterize perhaps the majority of potentially hazardous asteroids near Earth.