protoplanet
Planet in formation
A protoplanet is a large body of matter in orbit around a star that is in the process of becoming a planet.
These objects form when smaller particles of dust and rock in a disk around a young star collide and stick together, gradually accumulating mass through a process called accretion.
Protoplanets represent an intermediate stage between planetesimals (smaller rocky bodies) and fully formed planets.
The early solar system contained numerous protoplanets, some of which collided to form Earth and the other terrestrial planets.
Growth through external addition
- planetesimalPrimordial orbiting rock
- diskFlat circular object
- nebulaInterstellar gas formation
- coalescenceUniting into one mass
collision · gravity · dust · gas · embryo · solar system · orbit · migration
Recognizing meaningful differences
nickel · silicates · molten · magma · olivine · pyroxene · chondrite · metallic
Subterranean magma expulsion process
- tectonicsStudy of crustal deformation
- outgassingReleasing trapped gas
- atmosphereGaseous layer around planets
- crateringForming impact hollows
bombardment · heat · radioactive decay · convection · cooling · surface · basin · primordial
accretion
Growth through external addition
- planetesimalPrimordial orbiting rock
- diskFlat circular object
- nebulaInterstellar gas formation
coalescence · collision · gravity · dust · gas · embryo · solar system · orbit · migration · runaway growth
differentiation
Recognizing meaningful differences
iron · nickel · silicates · molten · magma · olivine · pyroxene · chondrite · metallic · volatiles
volcanism
Subterranean magma expulsion process
- tectonicsStudy of crustal deformation
- outgassingReleasing trapped gas
- atmosphereGaseous layer around planets
cratering · bombardment · heat · radioactive decay · convection · cooling · surface · basin · primordial · hydrogen
- solar systemsun, Earth, Mars, Jupiter, Saturn
- spacespace, sun, moon, stars, star
- Rocky PlanetsEarth, Mars, Venus, rocky planets, super-Earths
- planetary formationplanetesimals, solar nebula, planetesimal, snow line, differentiation
- Proto- wordsprototype, protocol, protozoa, protoplasm, protostar
- substellar objectsbrown dwarf, failed star
protoplanetplanet
Star-orbiting spherical body
terrestrial planet · gas giant · ice giant · dwarf planet · planetesimal