List of Apollo asteroids
The Apollo asteroids are a group of near-Earth asteroids named after 1862 Apollo, the first asteroid of this group which was discovered by Karl Wilhelm Reinmuth. They are Earth-crosser asteroids that have orbital semi-major axis greater than that of the Earth (> 1 AU) but perihelion distances less than the Earth's aphelion distance (q < 1.017 AU).
As of August 2015[update], the Apollo asteroid group includes a total of 6,923 known asteroids of which 991 are currently numbered. Asteroids are not numbered until they have been observed at two or more oppositions. More than a thousand Apollo asteroids are large enough and may get close enough to Earth to be known as potentially hazardous asteroids.
The closer their semi-major axis is to Earth's, the less eccentricity is needed for the orbits to cross. The February 15, 2013 Chelyabinsk meteor that exploded over the city of Chelyabinsk in the southern Urals region of Russia, injuring an estimated one thousand people with flying glass from broken windows, was an Apollo class asteroid.
The largest known Apollo asteroid is 1866 Sisyphus, with a diameter of about 8.5 km. Examples of known Apollo asteroids include:
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- "numbered objects and orbital class (APO)". JPL Solar System Dynamics. Retrieved 2015-08-10.
- "JPL Small-Body Database Search Engine: PHAs and orbital class (APO)". JPL Solar System Dynamics. Retrieved 2015-08-10.
- Cantor, Matt (26 February 2013). "Scientists figure out Russia meteor's origin Ron Jeffery". USA Today.
- The Spacewatch Project, Arizona Board of Regents, 2010