Planet is Youngest

ASTRONOMERS have discovered a planet less than a million years old – the youngest known.

It is 420 light years away circling a star called CoKu Tau 4.

Most planets outside our solar system are thought to be at least a billion years old and to have formed by objects smashing together.

But it is thought the new planet was created much faster as solar dust stuck together.

Earth is 4.5billion years old.

Dan Watson, of the University of Rochester, New York, said: “It really causes problems for the major theories of planetary formation.”