A US Marine leads two Viet Cong suspects in restraints during the Tet Offensive on February 20, 1967. (Photo by Bettmann Archive/Getty Images)

Medic James E. Callahan of Pittsfield, Mass., gives mouth-to-mouth resuscitation to a dying soldier in war zone D, about 50 miles northeast of Saigon, June 17, 1967. Thirty-one men of the 1st Infantry Division were reported killed in the guerrilla ambush, with more than 100 wounded. (Photo by Henri Huet/AP Photo)

Police investigators inspect the bodies of two men lying on a sidewalk, who police said were killed after a drug “Shabu” (Methamphetamine Chloride) buy-bust operation in Quezon city, Metro Manila Philippines, October 9, 2016. (Photo by Ezra Acayan/Reuters)

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.

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")

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)

In this March 7, 1991 file photo, a U.S. Marine patrol walks across the charred oil landscape near a burning well during perimeter security patrol near Kuwait City. Twenty five years after the first U.S. Marines swept across the border into Kuwait in the 1991 Gulf War, American forces find themselves battling the extremist Islamic State group, born out of al-Qaida, in the splintered territories of Iraq and Syria. The Arab allies that joined the 1991 coalition are fighting their own conflicts both at home and abroad, as Iran vies for greater regional power following a nuclear deal with world powers. (Photo by John Gaps III/AP Photo)