protoplanet

[ proh-toh-plan-it ]

noun

, Astronomy.

1. the collection of matter, in the process of condensation, from which a planet is formed.

protoplanet

/ ˌprəʊtəʊˈplænɪt /

noun

1. a planet in its early stages of evolution by the process of accretion

Word History and Origins

Origin of protoplanet¹

First recorded in 1945–50; proto- + planet

Example Sentences

It’s hoped the mission will provide a better sense of the asteroid’s composition, confirm whether it is indeed the core of an ancient protoplanet, and yield insights into the solar system’s violent past.

From Singularity Hub 

The researchers found that about half of the time, incoming protoplanets grazed Earth without directly colliding.

From Science News

Earth would have ended up with more of the outer mantle and crust material from the incoming protoplanets, while Venus would have gotten more of their iron-rich cores.

From Science News

Then there are protoplanets, a planet that’s almost done forming.

From Science News For Students

During the chaos of the Bombardment Epoch, water from asteroids and volatile elements from the protoplanet fall to the gravitational attraction of a young planet Earth.

From Nautilus