Halley becomes second Astronomer Royal In 1720, English astromoner Edmund Halley succeeded John Flamsteed as the second Astronomer Royal, taking up the post at Greenwich, where he observed the transits of the moon across the meridian and continued to work on the problem of determining longitude at sea. Image Credit Portrait of Edmund Halley. 'Edmundus Halley, Soc. Reg. Soc. Astronamus Regius et Geometriae Professor Savilianus', mezzotint print by George White after Sir Godfrey Kneller. Edmundus Halley, Soc. Reg. Soc. Astronamus Regius et Geometriae Professor Savilianus. ID: PAF3352. National Maritime Museum, Greenwich, London, CC BY-NC-ND 3.0, https://www.rmg.co.uk/collections/objects/rmgc-object-127487
