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 kilometers), 3200 Phaethon, 1685 Toro, and 4179 Toutatis.