2830 Greenwich

2830 Greenwich, provisional designation 1980 GA, is a stony Phocaea asteroid from the inner regions of the asteroid belt, approximately 9 kilometers in diameter. It was discovered by American astronomer Edward Bowell at Lowell's U.S. Anderson Mesa Station, Arizona, on 14 April 1980.

The stony S-type asteroid is a member of the Phocaea family, a group of asteroids with similar orbital characteristics. It orbits the Sun at a distance of 1.9–2.9 AU once every 3 years and 8 months (1,340 days). Its orbit has an eccentricity of 0.21 and an inclination of 25° with respect to the ecliptic. The first precovery was obtained at Crimea-Nauchnij in 1969, extending the asteroid's observation arc by 11 years prior to its discovery.

In 2002, a photometric light-curve analysis by French amateur astronomer Christophe Demeautis gave an ambiguous rotation period of 24 hours with a brightness amplitude of 0.5 in magnitude (U=2). According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, the asteroid measures between 7.9 and 9.5 kilometers in diameter, and its surface has an albedo between 0.17 and 0.19. The Collaborative Asteroid Lightcurve Link selects 9.3 kilometer as the best diameter estimate.

The minor planet is named for the Royal Greenwich Observatory, home of the Astronomer Royal and located in the London borough of Greenwich, England. The naming took place on the occasion of the centennial of its adoption as "the Greenwich prime meridian for longitude and time". Founded for naval purposes in 1675, the Royal Observatory quickly became a leading institution in astronomy. In 1884, the prime meridian finally became a worldwide standard. Naming citation was published on 15 May 1984 (M.P.C. 8801).