noun
(cosmology) the theory that the solar system was formed by the gravitational accumulation of planetesimals
• Hypernyms: ↑scientific theory
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noun : a hypothesis in astronomy: the planets have evolved by aggregation from planetesimals
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planetesimal hypothesis or planetesimal theory,
the hypothesis that minute bodies in space move in planetary orbits and gradually unite to form the planets of a given planetary system.
Useful english dictionary. 2012.