Protoplanet

Protoplanet [ to Greek protos "first" ], according to the common theory of the term for the precursor of a planet. The development stage is in the planets history between the planetesimals and the final planet.

Development

When compressed, the main mass of the solar nebula to a proto sun, formed within remaining gas and dust particles circumsolar an accretion disk. In this protoplanetary disk to dust particles have aggregated by accretion or by bonding due to the adhesion force to to about the extremely large planetesimals. This united. Due to their gravity to larger matter densities, the protoplanets, which could obtain the size of the moon in about Been sufficiently massive to be acquired through a hydrostatic equilibrium an approximate spherical shape and form by differentiation of its interior a shell structure. The further growth up to a full-fledged planet is only by gravity is not possible, but comes into being through collisions on intersecting orbits that lead to disintegrations.

Examples

A collision of the developed proto earth with the protoplanet Theia ( about the size of Mars ) is said to have led to the mass of the earth and at the same time the formation of the Moon.

Protoplanets come before both the Kantian and in the Laplace theory (Kant -Laplace theory ), the first hypotheses regarding the origin of the solar system.