Spherical Shape of Planets | 29 May 2024

The spherical shape of planets is largely attributed to the interplay of gravity and geometry.

Gravity is the primary force shaping planets, compelling them into a spherical form due to their massive size.
A sphere offers the most compact three-dimensional shape, minimising surface area for a given volume.
While commonly referred to as spherical, planets and stars are actually oblate spheroids, slightly flattened at the poles due to centrifugal force from rotation.
Rotation creates a centrifugal force, resulting in a slight bulge at the equator, making gravity weaker in this region compared to the poles.
Gravity tends to shape celestial bodies into spheres, while smaller bodies such as comets and asteroids maintain irregular shapes due to stronger electromagnetic forces.