Protoplanet
Protoplanet
Image from Steve Bowers

Massive object resulting from the coalescence of planetesimals in the solar nebula, which eventually becomes a mature planet. Protoplanets are constantly impacted by other objects in the protoplanetary swarm, so are often very hot, with a molten or semi-molten surface.

Has a thick primary atmosphere, generally of hydrogen and helium, much of which will be lost unless the planet gains enough mass to become a gas giant. Because of the potential for mining and megascale engineering, protoplanets are often highly sought after by interstellar development corporations and certain clades and hyperturings.

 
Related Articles
 
Appears in Topics
 
Development Notes
Text by M. Alan Kazlev and Steve Bowers

Initially published on 19 December 2001.