The Solar System

Planetary Systems

What are planetesimals?

Planetesimals are early solar system objects that range in size from about 0.6 to 60 miles (1 to 100 kilometers) across. Like so many terms in science, this is not an exact definition. More generally, it refers to objects in the protoplanetary nebula that have formed by collisions and may be starting to accrete more material via their gravitational influence.


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