Mercury is tiny, barely bigger than the Moon. Its metallic core makes up 70% of the planet’s mass, vastly exceeding Earth’s ...

New simulations suggest that Mercury's formation could be the result of a rare collision between two celestial bodies of similar mass.

Astronomers have announced that a mystery object orbiting a star 170 light-years from Earth might have formed from the collision and merger of two protoplanets. The object, known as 2M1207B, has ...

The moon did indeed coalesce out of tiny bits of pulverized planet blasted into space by a catastrophic collision 4.5 billion years ago, two new studies suggest. The new research potentially plugs a ...