On the other hand, it is unclear whether such moons could form in the first place.

Various theories have been proposed to explain how the Moon formed.

"It shows that the Moon formed relatively late," he said.

"When the three moons form a triangle that points to the heart of heaven."

Subsequently, two moons form in the sky, signifying the end of the world.

The Moon formed as a dry body, many believe, and any water present would have come from its bombardment by comets.

In addition it is unclear whether such moons could form in the first place.

The results exploded the long-held theory that the moon once formed part of the Earth.

That would fit current ideas that the Moon did not form at the same time as Earth.

Pluto's moons may have formed from the scattered pieces of rock left behind after the collision.