I'm not sure where you got that idea, but there is certainly not only one moon in the universe. Our planet only has one moon, but most planets have several moons. You should do a search online for moons and look at some examples.
Ganymede is the largest known moon in the Milky Way Galaxy.
No, Earth only has one natural satellite, commonly known as the Moon.
The Sun is a star and emits solar light, and is at the centre of our Universe. The Moon is a small satellite planet that orbits the Earth, and only reflects the light striking the Moon's surface.
For earth there is only one moon and it has only one shape that is sphere...!
Mass is a constant everywhere in the universe. The weight on the moon is about one sixth of the weight on the earth, because the mass of the moon is about one sixth of the mass of the earth reducing the force of gravity.
There is only one Universe (as far as we know) and we are in it.
The One God, who created the universe, is the only God of Judaism.
Only One Moon was created on 1994-04-08.
Within our Solar System, the Earth is the only planet with one moon.
The Earth is the only planet in our Solar System with one Moon
Only Earth has exactly one moon.
Only the Earth has one moon.
Yes the earth has only one moon.
Yes only one side of the moon is always facing the earth.
Our Earth has only the one moon.
It's Earth. Yes, Earth only has one moon, but 5 of the other 7 have more than one moon. Only Mercury and Venus have no moons.
Only Earth has exactly one moon.