Protoplanet

Definition

A protoplanet is a large planetary embryo that originated within a protoplanetary disk. It is in the process of developing into a fully-fledged planet through accretion and collisions with other celestial bodies.

5 Must Know Facts For Your Next Test

1. Protoplanets form from the dust and gas in a protoplanetary disk around a young star.
2. They grow by the process of accretion, gathering material through gravitational attraction.
3. Collisions between protoplanets can lead to the formation of larger planets or cause fragmentation.
4. Our solar system's terrestrial planets likely formed from the collision and combination of several protoplanets.
5. The Moon may have formed from the debris of a giant impact between Earth and a Mars-sized protoplanet.

Review Questions

• What is the primary process by which protoplanets grow?
• How are terrestrial planets thought to have formed?
• What role do collisions play in the development of protoplanets?

Related terms

Accretion: The process by which particles stick together to form larger bodies like stars, planets, and moons.

Protoplanetary Disk: A rotating disk of dense gas and dust surrounding a newly formed star.

Terrestrial Planet: A type of planet that is composed primarily of silicate rocks or metals, such as Earth, Mars, Venus, and Mercury.