A NASA survey has identified around 1,000 asteroids that are large enough to cause catastrophic damage if they were to collide with Earth. This survey, known as Spaceguard, was mandated by Congress in 1998 to locate 90 percent of objects near Earth that are 1 km or larger in diameter. Astronomer Amy Mainzer announced at a conference in San Francisco that the survey is now 93 percent complete, with the use of NASA's WISE telescope. In addition to the larger asteroids, scientists also discovered approximately 20,500 smaller asteroids near Earth, which is fewer than previous estimates of 36,000 to 100,000 of these objects. Mainzer told Reuters that while the likelihood of an impact event is low, asteroids still have the potential to cause significant damage. A major asteroid strike has occurred in the past, with an asteroid or comet believed to have caused the extinction of dinosaurs and other species 65 million years ago. Mainzer highlighted the devastation that a large asteroid could cause, emphasizing the importance of monitoring potentially hazardous objects. Scientists are currently utilizing archived WISE observations to identify objects that may pose a threat to Earth if their orbits bring them within 4.6 million miles of our planet. As of now, there is no established plan for how to respond if an asteroid is found to be heading towards Earth.