A Russian trenchmortar crew run to take up a new firing position in the Stalingrad area during the Great Patriotic War. (Photo by Keystone/Getty Images). October 1942

Astronaut Edwin E. Aldrin Jr. walks near the Lunar Module during the Apollo 11 extravehicular activity July 20, 1969 on the Moon. (Photo by NASA/Newsmakers)

Singer Selena Gomez performs at the PNC Bank Arts Center on August 20, 2011 in Holmdel, New Jersey. (Photo by Michael Loccisano/Getty Images)

Then U.S. Army First Lieutenant Kirsten Griest (C) and fellow soldiers participate in combatives training during the Ranger Course on Fort Benning, Georgia, in this handout photograph taken on April 20, 2015 and obtained on August 20, 2015. When Griest and another woman completed the daunting U.S. Army Ranger school this week they helped end questions about whether women can serve as combat leaders, as the Pentagon is poised to open new roles, including elite Navy SEALs, to women in coming months. The feat by Griest and First Lieutenant Shaye Haver followed a re-evaluation of the role of women after their frontline involvement in Iraq and Afghanistan and the end of a rule barring them from combat roles in 2013. (Photo by Spc. Nikayla Shodeen/Reuters/U.S. Army)

Ecuadorian luthier Ivan Ibujes plays a guitar after repairing it at his shop in Quito, June 17, 2016. (Photo by Guillermo Granja/Reuters)

French First Lady Carla Bruni-Sarkozy waits for the spouses of the Heads of Delegation participating in the G8 Summit on May 26, 2011 in Deauville, France. (Photo by Franck Prevel/Getty Images)

Beekeeper and Chairman of The London Beekeepers Association John Chapple installs a new bee hive on an urban rooftop garden in Hackney on July 1, 2009 in London, England. (Photo by Dan Kitwood/Getty Images)