Also found in: Dictionary, Thesaurus.
Related to planetesimal theory: planetesimal hypothesis, Tidal theory, Nebular theory
planetesimal theory(plăn'ĭtĕs`əməl): see solar systemsolar system,
the sun and the surrounding planets, natural satellites, dwarf planets, asteroids, meteoroids, and comets that are bound by its gravity. The sun is by far the most massive part of the solar system, containing almost 99.9% of the system's total mass.
..... Click the link for more information. .