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Name: Daiva
Status: educator
Age: 40s
Location: N/A
Country: N/A
Date: 1999 

Asking on behalf of the class teacher who brought students to the lab: "Why planets are spherical?

If one weren't, it would collapse to a sphere under its own gravity. All the matter tries to fall toward the center, and will if there's nothing in its way. The sphere is the shape in which everything has fallen toward the center as far as it can.

Actually, planets bulge out a little at their equators, because of their rotation. So they're not exactly spherical, but pretty close.

Richard E. Barrans Jr., Ph.D
Assistant Director
PG Research Foundation, Darien, Illinois

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