Why Of All The Heavenly Bodies, Are Planets Generally Spherical In Nature ?

Question

Why Of All The Heavenly Bodies, Are Planets Generally Spherical In Nature ?

2 Answers

Answer Question

Answer 1

Hi
Very simple answer ,you can justify yourself any object which rotates at a particular speed you can found an imaginary boundary almost SPHERICAL around it.
Actually there is no boundary for the planets including earth ,since all masses & planets are rotating at a particular axis around the sun and with its own gravity it gives a shape especially spherical shape to the earth or other planets.
From
S.Pooja
Chennai
India

Answer 2

Because, by definition, planets have to be spherical (this was the vote of the IAU in 2006). If it's not spherical, it wouldn't be a planet.

And, because they are big enough to have enough mass that they generate enough gravity to force their mass into a pretty much spherical shape.

So really, gravity is the answer. All that stuff pulling at all that other stuff, all clumped together, a sphere is it's lowest energy state (most stable possible). Plus, when the planets were forming they were bits of material that were attracted to each other by gravity, and new bits got added on randomly but evenly over the surface of the clump, hence a pretty much spherical shape evolved.

Stars are also spherical, as are lmost moons. Even galaxies (not very dense) tend to have somewhat spherical shapes. It's only little things, like asteroids, comets and smaller stuff, that might not be mostly round.

Even the universe itself is possibly a donut shaped cylinder.