Wednesday, 3 April, 2002, 13:31 GMT 14:31 UK Spectacular planet show promised By BBC News Online's Helen Briggs The five planets visible to the naked eye will line up in the sky at the end of April. Astronomers say the rare grouping of Mercury, Venus, Mars, Jupiter and Saturn may not be seen again for a century. Robert Warren, Royal Observatory, Greenwich A similar arrangement of planets happened two years ago but was not visible from Earth because of the position of the Sun. It was accompanied by scare stories that our planet could be pulled off its path or...