Do you know

1
Astronomy
6
Do you know

• Why are planets spheres?
• Why is Pluto a dwarf planet?

They are big enough so that the gravitational
force pulls every part of the planet to the
center, causing it to be shaped like sphere.

• Is smaller than Mercury but large enough to have
  enough gravity to be a sphere.
• Orbits in a zone that has many other objects in
  it.

P. Reardon 2008 Based on Science Starters by
T. Trimpe at http//sciencespot.net/