Are all planets oblate spheriod ?
2020, May, 24
Curiosity
The shape of our planet Earth is not a sphere but it is oblate spheroid. The circumference measured by passing through it's north and south poles is lesser than the circumference at it's equator.
This leads to a question are all planets (that we know of) oblate spheroids ? Or what's the usual shape of other planets ?
Yes, other planets are also oblate spheroid. This is caused by two forces acting on the planet body.
- Gravity : It tries to pull all the matter of the planet towards the center turning the planet into a sphere.
- Rotational Force of spinning on it's axis : It tries to flatten all the matter.
The combination of these two forces leads to the equator of the planet having prominent bulge as compared to it's poles. The faster the planets spins the more prononced it's bulge is.