Also found in: Dictionary, Thesaurus.
Related to planetesimals: Planetesimal theory


(plan-ĕ-tess -ă-mălz) Bodies, ranging in size from less than a millimeter to many kilometers, that are thought to have formed the planets of the Solar System by a process of accretion.



the tiny solid particles that were the material for the formation of the planets according to the cosmogonical hypothesis advanced at the turn of the century by the American scientists F. Moulton and T. Chamberlin. The hypothesis attributed the formation of planetesimals to the cooling and condensation of matter ejected by the sun. This assumption, however, is not valid, since it is incapable of explaining the large distances and specific angular momenta of the planets. The term “planetesimal” is sometimes used in modern cosmogonical hypotheses and theories that consider the formation of the planets from solid particles.

References in periodicals archive ?
Small planetesimals quickly gather mass by collecting other rocky material on their orbit around the Sun.
Tens of planetesimals may form a single planet with
Third was the thought that Earth and Moon were formed from different swirls of planetesimals, and at some time in the past the Earth captured the Moon.
Another possibility is that this planetesimal bounced back into space and escaped entering the planet entirely.
Planetesimals were extremely abundant in our primordial solar system--and some of them have survived long enough to tell the long-lost story of this vast population of primordial objects.
Some dynamical aspects of the accretion of Uranus and Neptune--The exchange of orbital angular momentum with planetesimals.
Abstract: We describe the evolution of a protoplanetary disc from the initial accretion infall to FU Orionis outbursts to the formation of planetesimals.
Doing it right--that is, trying to capture the whole picture--includes starting ingredients called planetesimals.
They slowly migrated inwards, Uranus and Neptune switching places, and the planetesimals were scattered outwards.
It draws smaller particles to accrete onto larger ones, thereby building first planetesimals and then the larger bodies, planets.
In the process of planet formation, the gouts of solar matter condensed into small solid pieces called planetesimals, and these came together little by little to form planets.
sid=61a59819-cb87-4e00-a411-1cb0b74b5119) The study was titled "Percolative core formation in planetesimals enabled by hysteresis in metal connectivity" and was also co-authored by MaAaAaAeAaAaAeAeA a Prodanovic, who along with Hesse, was Ghanbarzadeh's advi