Beach Policeman, Potomac River, 1922. (Photo by National Photo Company/Colorized by Patty Allison)

The competition, which is run by the Royal Observatory Greenwich in association with BBC Sky at Night Magazine, is now in its sixth year and has received over 2,500 entries. Photo: Centre of the Heart Nebula by Ivan Eder (Hungary). Situated 7500 light years away in the “W”-shaped constellation of Cassiopeia, the Heart Nebula is a vast region of glowing gas, energized by a cluster of young stars at its centre. The image depicts the central region, where dust clouds are being eroded and moulded into rugged shapes by the searing cosmic radiation. (Photo by Ivan Eder)

Edward, Prince of Wales (1840–1910), later King Edward VII, stands over the carcass of a wild Chillingham bull, shot by himself during a visit to Chillingham Castle, Northumberland, circa 1879. (Photo by Hulton Archive/Getty Images)

Naturally, it is important that a baby learn the right habits. This woman demonstrates that smoking is wrong for babies. From a series of images parodying women's lifestyle and beauty magazines. (Photo by Jacobsen/Getty Images). 1955

Princess Elizabeth with her husband Prince Philip Duke of Edinburgh and their children Prince Charles and Princess Anne. (Photo by Keystone/Getty Images). August 1951

Linda Rooks from Yeovil in Somerset, a hostess at Whipsnade Zoo, wears “Tanga” a 7fy long python as a hat and scarf. (Photo by William Vanderson/Getty Images). 1965

In this July 10, 2014 photo, Chris Minore, of Orange, Conn., performs the under chop technique at the Adirondack Woodsmen's School at Paul Smith's College in Paul Smiths, N.Y. Eighteen young students in matching gray sports shirts took part recently in a weeklong crash course on old-school lumberjack skills such as sawing, chopping, ax throwing, log boom running and pole climbing. (Photo by Mike Groll/AP Photo)

Romanian singing duo Gabriella and Monica Irimia, The Cheeky Girls prforms in Falkirk, Scotland on May 4, 2003. (Photo by Michael Schofield/News Group Newspapers Ltd)