A C-17 Globemaster III crew prepares an air refueling mission September 27, 2012, at Joint Base Charleston, S.C. (Photo by Airman 1st Class Matthew J. Bruch/U.S. Air Force photo)

John Hawkley and his wife Patty Hawkley stand next to their 2,058 pound pumpkin and celebrate after winning the 41st Annual Safeway World Championship Pumpkin Weigh-Off on October 13, 2014 in Half Moon Bay, California. John Hawkley of Napa, California won the 41st Annual Safeway World Championship Pumpkin Weigh-Off and broke a state record with his gigantic pumpkin weighing in at 2,085 pounds. Hawkley took home a cash prize of $12,510, or $6.00 a pound. (Photo by Justin Sullivan/Getty Images)

Runners gather at the start line for the annual “Santa Speedo Run”, a charity race through the streets of the Back Bay neighborhood of Boston. (Photo by Gretchen Ertl/Reuters)

Old Heidelberg, Dog with Pipe, 1905. (Photo by Detroit Publishing Company)

Julian Rodriguez, of Everson, Wash., holds his two-gram packet of recreational marijuana outside Top Shelf Cannabis, Tuesday, July 8, 2014, in Bellingham, Wash., on the first day of legal sales in the state. (Photo by Ted S. Warren/AP Photo)

Merit Prize Winner: “A Well Earned Rest in the Sahara”. This photo of Moussa Macher, our Tuareg guide, was taken at the summit of Tin-Merzouga, the largest dune (or erg) in the Tadrat region of the Sahara desert in southern Algeria. Moussa rested while waiting for us to finish our 45-minute struggle to the top. It only took ten minutes of rolling, running, and jumping to get back down. The Tadrat is part of the Tassili N'Ajjer National Park World Heritage area, famous for its red sand and engravings and rock paintings of cattle, elephants, giraffes, and rhinos that lived there when the climate was milder. Photo location: Summit of Tin-Merzouga, Tadrat, Tassili N'Ajjer National Park, Algeria. (Photo and caption by Evan Cole/National Geographic Photo Contest)

Russian servicemen drive a partially covered T-14 Armata tank along a street before a rehearsal for the Victory Day parade in Moscow, Russia, April 29, 2015. Russia will celebrate the 70th anniversary of the victory over Nazi Germany in World War Two on May 9. (Photo by Maxim Zmeyev/Reuters)