Apollo group


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Apollo group

A group of near-Earth asteroids, including (1566) Icarus and (2201) Oljato, that have perihelia inside the orbit of the Earth (i.e. less than 1.017 AU). Like members of the Amor group, most are very small bodies and can be observed only when close to the Earth. The group takes its name from the 1.4-km-diameter asteroid (1862) Apollo, which was discovered when it approached within 0.07 AU of the Earth in 1932 by Karl Reinmuth but was lost because of uncertainties in its orbit; it was rediscovered in 1973. Radar observations of Apollo in 2005 by the Arecibo radio telescope revealed that a satellite is in close orbit around it. The spectra of several of the Apollo group asteroids closely resemble those of chondrite meteorites. Members of the Apollo and Amor groups are often classed collectively as Apollo–Amor objects, the perihelia of such bodies usually being taken as smaller than 1.3 AU. See Table 3, backmatter.