Thousands flock to Bondi Beach for the traditional expats Christmas Day celebration in Sydney, Australia, 25 December 2014. Expats of all nationalities have been flocking to Bondi Beach for Christmas Day for many years. (Photo by Dean Lewins/EPA)

An airplane passes the moon as it makes its approach to Philadelphia International Airport, Sunday, September 7, 2014, in Philadelphia. (Photo by Matt Rourke/AP Photo)

A large variety of weapons were for sale at the Washington County Fairgrounds Gun Show that drew thousands of people over the weekend, on March 22, 2013. (Photo by Gary Porter)

A dog rides a wave while competing during the 5th Annual Surf Dog competition at Huntington Beach, California, on September 29, 2013. (Photo by Frederic J. Brown/AFP Photo)

View at one of the sculptures by Swiss artist H.R. Giger during the opening of the Ars Electronica 2013 exhibition “HR Giger. The Art of Biomechanics” in Linz, Austria, 04 September 2013. (Photo by EPA/RUBRA)

A curious leopard cub toys with a camera at MalaMala Game Reserve in Mpumalanga Province, South Africa. (Photo by Barcroft Media)

The giant mural titled “Under the Hand” by Maclaim Crew is visible on a building facade in Kreuzberg district on June 26, 2014 in Berlin, Germany. Berlin, with its long tradition of counter-culture, has become a mecca for street art of all dimensions and messages. (Photo by Sean Gallup/Getty Images)

World Champion Matthias Dolderer of Germany flies over the Horseshoe Bend near Lake Powell in Page, United States during the transfer flight from Indianapolis to Las Vegas to prior the final stage of the Red Bull Air Race World Championship on October 12, 2016. (Photo by Predrag Vuckovic/AFP Photo)