A couple passes the sculpture “Transformer” by Chinese artist Bi Heng during snowfall in Kassel, central Germany, Tuesday March 12, 2013. Frankfurt airport closed, a quarter of flights out of Paris were canceled, Belgium suffered record traffic jams and high-speed trains were stuck in stations – all because of a sudden dump of oddly late snowfall on Western Europe. Less prepared for the kind of heavy snow that regularly hits northern and eastern neighbors, France, Britain and Belgium struggled Tuesday to keep moving amid the frosty, blustery conditions. (Photo by Uwe Zucchi/AP Photo/Dpa)

Harris & Ewing Inc. photographed people, events, and architecture, particularly in Washington, D.C., during the period 1905-1945. Photo: Tests of Curtiss Palne for Army, Single Control. Created by Harris & Ewing. Published in 1912.

An Emirati child plays with an airplane model near the venue of the Mazayin Dhafra Camel Festival, on December 20, 2012 near the city of Madinat Zayed, 150 kms west of Abu Dhabi. The festival, which attracts participants from around the Gulf region, includes a camel beauty contest, a display of UAE handcrafts and other activities aimed at promoting the country's folklore. (Photo by Karim Sahib/AFP Photo)

Shortlisted: Pooyan Shadpoor, Houcheraghi. While walking along the shore of Larak, Iran – an island in the Persian Gulf – Shadpoor came across this luminous scene. The “magical lights of (the) plankton ... enchanted me so that I snapped the shot”, he writes. (Photo by Pooyan Shadpoor/2016 EPOTY)

Shipping containers sit idle at the ports of Los Angeles and Long Beach, California in this aerial photo taken February 6, 2015. The loading and unloading of cargo freighters has been suspended at all 29 U.S. West Coast ports this weekend because of chronic slowdowns on the docks that shippers and terminal operators have blamed on the dockworkers' union, the companies said Friday. (Photo by Bob Riha, Jr./Reuters)

Astronaut Donald R. Pettit would often rig an array of as many as six cameras in the cupola windows and set them all to fire continuously for events such as sunsets, which only last around seven seconds on the ISS. (Photo by Donald R. Pettit)

An Afghan girl makes a pile of unbaked bricks near the road passing through the Shamali Plains, about 10 kilometers (6 miles), west of Bagram, Afghanistan, Wednesay April 9, 2003. Children assist parents in their job to supplement family income. (Photo by Gurinder Osan/AP Photo)

Wild elephants, including a tusker (C), rummage through garbage dumped at an open ground in the village of Digampathana in north- central Sri Lanka on August 19, 2017. Sri Lanka has banned the dumping of garbage at open fields and near wildlife reserves, but the practice continues. (Photo by Lakruwan Wanniarachchi/AFP Photo)