Visitors look at graffiti art created by Brazilian artist Image during the 3rd annual Graffiti Fine Art Biennial International exhibit, at the Pavilion of Brazilian Cultures, in Sao Paulo, Brazil, Tuesday, April 21, 2015. The month-long event features the work of more than 60 street artists, representing 11 countries. (Photo by Andre Penner/AP Photo)

Members of the “Familia Gladiatoria Carnuntina” fight in the historic amphitheatre during the Roman Festival at the archeological site of Carnuntum in Petronell, Austria, June 11, 2016. (Photo by Leonhard Foeger/Reuters)

In this Wednesday, July 13, 2016, handout image provided by Solar Impulse, the Solar Impulse 2 flying over the pyramids, Egypt Cairo. The experimental solar-powered airplane has arrived in Egypt as part of its global voyage. (Photo by Jean Revillard, Rezo via the AP Photo)

“A Hawaiian photographer braved freezing temperatures for this cold SNAP – of what appears to be a firebird bursting from an aurora. Keen snapper CJ Kale, more used to sun, sea and sand while at work than snow, captured the incredible moment while on a trip to Alaska. It was his first time seeing the spectacular sight and lucked out – capturing some of the rarest colors of aurora on his first night”. – Caters News

Activists dismantle Ukraine's biggest monument to Lenin at a pro-Ukrainian rally in the central square of the eastern city of Kharkiv, Ukraine, Sunday, September 28, 2014. (Photo by Igor Chekachkov/AP Photo)

A Filipino pet owner carries her dog as she prays before the animal blessing rites at the Our Lady of Remedies Parish Church in Malate district, Manila, Philippines on Sunday, October 5, 2014. Several Filipinos brought their pets to be blessed during the annual event which is also done to celebrate the feast day of St. Francis of Assisi, the patron saint of animals and ecology. (Photo by Aaron Favila/AP Photo)

A pro-independence protester sits in front of Catalonia's regional parliament as lawmakers vote inside, in Barcelona, January 16, 2014. (Photo by Albert Gea/Reuters)

Hungarian wrestlers fight during the Hungarian wrestling Championship in Budapest November 29, 2014. (Photo by Laszlo Balogh/Reuters)