Worlds of David Darling
Encyclopedia of Science
Home > Encyclopedia of Science

Apollo group

typical orbits of Apollos, Atens, and Amors
Typical orbits of Apollo-, Amor-, and Aten-type asteroids.
Image credit: ESA

The Apollo group, also known as Earth-crossing asteroids, is one of three groups of near-Earth asteroids. Apollo group asteroids have semimajor axes greater than 1.0 AU and perihelia less than 1.017 AU (Earth's aphelion distance).

Some Apollo objects can approach closer than Mercury to the Sun, the record-holder being 1995CR with a perihelion distance of 0.12 AU. Other notable members of the group include (1862) Apollo (the prototype), (1866) Sisyphus (the largest, with a diameter of about 8 km), (3200) Phaethon, (1685) Toro, and (4179) Toutatis.

Related category