There are two major factors on which shape of the celestial body depends:
Gravitation Pull: The shape of a body is determined by the interaction between its gravity and solidity. It is simple
’s law of Gravitation, whenever we have huge mass close enough, each particle start experiencing the gravitational force towards the centre. This gravitation pull is equal in all directions, which results into a spherical shape. Newton
Gravity of the significantly larger moons and planets is so strong; by contrast, that it turns these celestial bodies into spheres. That is reason almost all the stars and big planets are spherical.
Planet Mars; Image Credit: NASA
Celestial objects that are too small for gravity to pull them into spherical shape can have a variety of shapes. Small asteroids and comets have little gravity, which is insufficient to force their larger rocks into a spherical distribution.
Comet; Image Credit: NASA
Asteroids; Image Credit: NASA
Shape of a celestial body may also depend on the Tidal forces and internal motions.
Written By: DMR