planetesimal(redirected from Planetesimal theory)
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Any of innumerable small bodies thought to have orbited the sun during the formation of the planets.
(Astronomy) any of a number of small bodies formerly thought to have been drawn from the sun by the close passage of a star to the sun, eventually coalescing to form the planets
(Astronomy) of or relating to planetesimals
plan•e•tes•i•mal(ˌplæn ɪˈtɛs ə məl)
one of the small celestial bodies that, according to one theory, were fused to form the planets of the solar system.
[1900–05; planet + (infinit) esimal]