noun
- a celestial body in the early stages of planetary formation, formed from the accretion of dust and gas in a protoplanetary disk
Usage: astronomy
Examples
- Scientists believe that protoplanets collided and merged to form the planets we see today.
- The protoplanet accumulated material from the surrounding disk of debris.
- Jupiter likely began as a protoplanet that grew massive enough to capture gas.
- Computer simulations show how protoplanets migrate within their stellar systems.
- The discovery of protoplanets around young stars supports theories of planetary formation.
- Protoplanets can range in size from small asteroids to objects larger than Mars.