Aten asteroids are Near Earth Asteroids (NEAs) with aphelion distances greater than 0.983 AU, and semi-major axis less than 1 AU. This means that they have orbital periods of less than a year and spend the majority of their time hidden by the Sun. Named for their prototype, 2062 Aten, there are currently about 300 known, some of which are also classified as Potentially Hazardous Asteroids.

The expected lifetimes of Aten asteroids are relatively short due to their potential to collide with the inner planets. This means that the population was not formed in place and must be continually replenished. Although some are no doubt extinct cometary nuclei, it is now thought that the majority originate in the main asteroid belt and are injected into their present orbits through gravitational interactions with Jupiter.