The First U.S. Spacewalk – Gemini 4 Ed White made the United States' first spacewalk on June 3, 1965 during the Gemini 4 mission. The extra-vehicular activity (EVA) started at 19:45 UT (3:45 p.m. EDT) on the third orbit when White opened his hatch and used the hand-held manuevering oxygen-jet gun to push himself out of the capsule. (Photo by NASA)

This strange coral-looking specimen is actually a mushroom. The photo, “Beautiful Destroyer”, was taken in the Panamanian tropical rainforest where the mushroom produces nitrogen, an element vital to soil health. (Photo by Sarah A. Batterman)

A selection of work by four photojournalists who have won grants of $10,000 and editorial support from the agency. Here: “Chasing Winter” by Katie Orlinksy. In late summer and early autumn polar bears flock to the native village of Kaktovik in the Alaskan Arctic to eat at “the boneyard” – the remains of whales annually hunted by the community. (Photo by Katie Orlinsky/Getty Images)

Italian actress Sophia Loren attends the Cannes Film Festival in Cannes, France, 1954. (Photo by AGIP/RDA/Getty Images)

With its huge eyes, comical name and diminutive size, Mark R. Smith’s image of a baby Hawaiian bobtail squid can’t help but raise a smile. A curiously endearing creature, the cephalopod is just 1.5cm across, its mantle cavity bearing more than a passing resemblance to a rather natty shower cap. But it is also a beautiful example of symbiosis – nature’s version of “I’ll scratch your back if you scratch mine” – for on the underside of the squid is a light organ which houses bioluminescent bacteria. The squid offers the bacteria protection and food, while the bacteria emit a glow – a handy trait that the squid uses to offset its silhouette, helping it to evade predators in the depths below. Mark R. Smith’s entry combines several images of a Hawaiian bobtail squid with different focus lengths to create a final picture with greater depth of field than normal. (Photo by Mark R. Smith/Wellcome Images/Macroscopic Solutions)

A doll in a children's gas mask is seen amongst beds at a kindergarten in the abandoned city of Pripyat near the Chernobyl nuclear power plant in Ukraine on March 28, 2016. Deadly radiation still spews from Chernobyl 30 years after the worst nuclear meltdown in history, as a newly built giant arch is pulled into place to cover the stricken reactor for the next century. (Photo by Gleb Garanich/Reuters)

Sgt. William Olas Bee, a U.S. Marine from the 24th Marine Expeditionary Unit, has a close call after Taliban fighters opened fire near Garmsir in Helmand Province of Afghanistan, May 18, 2008. (Photo by Goran Tomasevic/Reuters)

Actors perform “The Passion of Jesus” to crowds in Trafalgar Square on April 22, 2011 in London, England. The actors come from the Wintershall Estate in Surrey where they also perform a Nativity play in and around the farm buildings at Christmas. (Photo by Peter Macdiarmid/Getty Images)