LONDON, ENGLAND - SEPTEMBER 08: Visitors to The London Eye ferris wheel view the near full moon in Whitehall on September 8, 2014 in London, England. A supermoon or harvest moon involves a full moon coinciding with it's closest approach to the Earth on it's elliptical orbit. This is the third sighting of a supermoon this year with it occuring in full tonight.  (Photo by Peter Macdiarmid/Getty Images)