Visitors review their cell phone photos of an installation called “Plexus A1” by artist Gabriel Dawe, one of nine large-scale art installations displayed at the “Wonders” exhibit at the Renwick Art Gallery in Washington, DC, Wednesday, January 13, 2016. Built in the 1860s, the Renwick was the first American building to be designed specifically as an art museum; it recently reopened after a two year renovation. (Photo by Jim Lo Scalzo/EPA)

Two dogs sent into outer space by the Soviet Union after their safe return to earth. They spent 22 days in orbit. (Photo by Central Press/Getty Images). 22nd March 1966

Two sailors from HMS Fury enjoy a smoke with two women in bathing suits on a beach in Jersey, where their ship is on a visit. (Photo by William Vanderson/Fox Photos/Getty Images). 29th June 1935

A polar bear fast asleep at London Zoo. (Photo by Fox Photos/Getty Images). 1961

The sun shines on trees that are displaying their autumn colours surrounding Palladian bridge and the lakeside Pantheon at the National Trust's Stourhead on November 3, 2010 near Warminster, England. (Photo by Matt Cardy/Getty Images)

Television actress Catherine Fuller visits Trafalgar Square in London and feeds the famous pigeons. (Photo by Harry Kerr/BIPs/Getty Images). 26th June 1956

The world heavyweight boxing champion Joe Frazier, before his fight with Joe Bugner. (Photo by Evening Standard/Getty Images). 18th June 1973

Margaret Morris dancers exercising on the sands at Saint-Idesbald. (Photo by Fox Photos/Getty Images). August 1929