Asteroid families "Aten, Apollo, Amor" have orbits that cross that of the Earth. They present a danger of a collision. However, such a collision is highly unlikely: the last catastrophic collision was more than 65 millions years and none is planned in the near future. Only small and often unknown objects can strike the Earth as 2008 TC3 which fell in Sudan on Oct. 7, 2008. This happens regularly, causing the "shooting stars." Eros is the largest known NEO (Near Earth Object), and was observed by the NEAR space probe in the years 2000 and 2001.

The asteroid 3753 Cruithne is very special: it is a companion of the Earth on its orbit. Its movement oscillates on this orbit alternately toward and away from Earth. The asteroid Apophis is one of those which uses to approach very close to the Earth (about 30 000km from the surface in 2029). The asteroid 2002 VE68 could also be a quasi-satellite of Venus.