'Potentially hazardous' Asteroid (52768) 1998 OR2 to pass Earth

A giant asteroid classified by astronomers as "potentially hazardous" is set to become the largest to pass earth this year.

The two-mile-long rock is expected to race past on Wednesday, coming within 4 million miles of the planet.

Called Asteroid (52768) 1998 OR2, is thought to be travelling at almost 19,500 miles per hour.