AN ASTEROID said to be the size "of a cruise ship" should be visible over Wales tonight, giving star-gazers a chance to see the once in 200-year event.

The orbiting lump of rock will pass just 745,000 miles, or 1.2 million km from earth.

The visitor should be visible over Wales at 8pm facing south-east between Jupiter and the bright star Sirius.

Don Yeomans of Nasa said the asteroid poses no threat to Earth for the foreseeable future: "It's a relatively close approach by a relatively large asteroid, so it provides us a unique opportunity to observe and learn more."