After lots of tests and computer model runs astronomers Martin Jutzi and Erik Asphaug came up with the scenario to explain why the moon’s far side have so much more hills than the one that is always facing Earth.
The theory outlined in the journal Nature comes with an artist’s render of the collision of the two moons.
This is supposedly happened 4.4 billion years ago when there was no life on Earth. Moons were young, formed barely 100 million years earlier when a giant planet smashed into Earth. Both moons orbited Earth and sort of rose in the sky together, the smaller one trailing a few steps behind the big one.
Though parked a bit away from each other, bigger one had gravity so strong that little one couldn’t resist it, so they were destined to collide.
The merging happened in a slow crash, what is relative in planetary smashups. It happened at more than 5,000 mph, what was slow enough that the rocks didn’t melt. This way rocks and crust from the smaller moon would have spread over and around the bigger moon without creating a crater what faster crash would have done.
Study was an attempt to explain the odd crust and mountainous terrain of the moon’s far side, since it looked as if something had been added to the surface.
Earth’s one Moon was odd due to the fact that Venus and Mercury have no moons; Mars has two, while Saturn and Jupiter have more than 60 each. Even tiny Pluto, which was demoted to dwarf status, has four moons.