About the Author
Ian Morison is a radio astronomer at the Jodrell Bank Observatoryfor whose website he produces a monthly sky guideand a professor of astronomy and cosmology at the University of Manchester. He also contributes articles and reviews for Astronomy Now and New Scientist. Margaret Penston is the president of the United Kingdom's Society for Popular Astronomy and the chair of the Royal Astronomical Society’s Education Committee. She is a former staff member of the Royal Observatory, Greenwich, and was a member of the European Space Agency's Hipparcos project team.