Quote:
Originally Posted by RedDevil
Yes. But does that matter?
Ganymede is bigger than Mercury, and Mercury has no moons.
Pluto does have moons; its biggest, Charon, has 1/8 of the mass of Pluto and is the 8th biggest moon in our solar system (not counting Pluto or Mercury in as moons).
And that link to Charon has a nice dig into the subject:
If it were me I'd add "... a planet be defined as a body that orbits just the Sun and no other object within the solar system ..." so the moon and Charon remain moons as long as they keep circling around their main planet, never mind the position of their combined center of gravity. |
There are about 100 other unnamed objects in our solar system - that are LARGER than Pluto. Why aren't they all planets?