Astronomers say hundreds of meteors will streak across the sky in a display that may be visible around the world. The Perseid meteor shower occurs every July and August as the Earth passes debris from the Swift-Tuttle comet. The BBC Weather centre said it would peak from 23:00 BST on Saturday and could be seen in most parts of the UK. However, experts say the Perseids could be harder to see this year as the Moon will be three-quarters full.