Moons do not have to be any size but if the moon is bigger than the planet that it orbits, then the moon becomes the planet because it has more gravitational force.
Venus has no moons.
there are 63 moons and 4 of them are big
no moons but have big craters
Mars has two very tiny moons. Jupiter and Saturn also have lots of small moons, but they also have lots of big moons.
They're fairly big for moons, although Jupiter itself is big. The four "Galilean" moons of Jupiter were the first "moons" other than our own Moon to be seen, by Galileo using his new telescope.
All planets moons revolve around their planet, no matter how many moons the planet has. Mars' moons, Phobos and Deimos, mean fear and terror.
Because it is big
Uranus has at least 27 moons that we know of.
If you mean the moons of the planet Jupiter- there are 67 moons in total. 53 of them have names. 14 do not (yet) have a name. That's a lot of moons- but Jupiter is a BIG planet.
Moons are big rocks in space so they are not created all the same way.
The biggest moon is "Ganymede" which is a moon of Jupiter.
The four large moons on Jupiter, or Galilean moons for the astronomer who discovered them, are called Io, Europa, Ganymede, and Callisto.