Mercury once had vast lava ocean

Mercury may once have had a large ocean of magma, Messenger data shows, shortly after its formation about 4.5 billion years ago.

Astronomers puzzled as star's dust belt vanishes

In just three years, the cloud of dust surrounding a young star has disappeared, indicating that there's something wrong with our current ideas of planet formation.

Moon may be millions of years younger than thought

A new analysis of a piece of lunar rock indicates that the moon is much younger than previously thought - or else scientists have been dramatically wrong about the way in which it was formed.