The Near-EarthObjectObservationProgram, commonlycalled "Spaceguard, " alsoplotstheorbitsofthese objects todetermineif any could bepotentiallyhazardoustoourplanet.
The US space agency's (Nasa) Near Earth Object programme reports on its website that it has recorded 1068 known "Potentially Hazardous Asteroids", however there are thousands more estimated to be present in space.