Mary McHugh mourns her slain fiance Sgt. James Regan at “Section 60” of the Arlington National Cemetery May 27, 2007. Regan, a US Army Ranger, was killed by an IED explosion in Iraq. (Photo by John Moore/Getty Images)

View of a Spitfire from the cockpit of an He111,somewhere over Southern England 1941 – 2014. (Photo by Adam Surrey)

Eva Longoria Farmer Visits "The Tonight Show Starring Jimmy Fallon" at Rockefeller Center on November 24, 2015 in New York City. (Photo by Theo Wargo/NBC/Getty Images for "The Tonight Show Starring Jimmy Fallon")

While vacationing on the Maldives Islands, Taiwanese amateur photographer Will Ho stumbled onto an incredible stretch of beach covered in millions of bioluminescent phytoplankton. These tiny organisms glow similarly to fireflies and tend to emit light when stressed, such as when waves crash or when they are otherwise agitated. While the phenomenon and its chemical mechanisms have been known for some time, biologists have only recently began to understand the reasons behind it. Photo: Bioluminescent phytoplankton washes up on Maldives beach. (Photo by Will Ho)

In the water of the Red Sea, seventy meters off the shore of Eilat, a unique underwater attraction was created - the Red Sea Star - the only underwater restaurant and bar in the world.

In this Sunday, September 18, 2016 photo, participants wait on stage ahead of Miss Trans Star International 2016 show celebrated in Barcelona, Spain. (Photo by Emilio Morenatti/AP Photo)

A Republican farmer defending a farm on the outskirts of Irun against Nationalist forces during the Spanish Civil War, 6th September 1936. A comrade lies dead by his side. (Photo by Keystone/Hulton Archive/Getty Images)