People watch a competitor riding a homemade vehicle without an engine on a 300-metre-track during the Red Bull Soapbox Race in Amman, Jordan September 4, 2015. (Photo by Muhammad Hamed/Reuters)

People take part in The Color Run in Brussels, Belgium September 6, 2015. The Color Run is a five-kilometre, untimed race, held in cities worldwide, with the aim of promoting healthy living. Participants are doused from head to toe in different colors at each kilometre. (Photo by Yves Herman/Reuters)

General views of atmosphere during the Regatta Storica during the 72nd Venice Film Festival on September 7, 2015 in Venice, Italy. (Photo by Tristan Fewings/Getty Images)

Rihanna attends the Balmain show as part of the Paris Fashion Week Womenswear Fall/Winter 2014-2015 on February 27, 2014 in Paris, France. (Photo by Dennis Leupold/The Guardian)

This photo taken on December 2, 2015 shows a lenticular cloud forming as white streaks from airplanes mark the blue sky, in a rare atmospheric phenomena above the town of Gevgelija on December 2, 2015. Lenticular clouds have been regularly confused for UFOs throughout history due to the their smooth, round or oval lens-shaped structure. (Photo by Armend Nimani/AFP Photo)

Brandy Shelton of Greensboro, North Carolina, “twerks” for a group of bikers on Ocean Boulevard during the 2015 Atlantic Beach Memorial Day BikeFest in Myrtle Beach, South Carolina May 22, 2015. After three people were killed and seven wounded in shootings during 2014 Bikefest, State officials called for an end to the event that draws thousands to the family-friendly beach town.Their efforts were unsuccessful. Bikers returned to Myrtle Beach – just a week after a bloody motorcycle gang shootout in Waco, Texas. But this time authorities are more prepared, with dozens of new surveillance cameras and a police force three times the size of last year's. (Photo by Randall Hill/Reuters)

Relatives and friends react during the funeral of Bryan Sandoval, 17, a victim of a landslide that has left at least 112 dead and 350 missing people, in El Cambray II village, Santa Catarina Pinula, Guatemala, 04 October 2015. The landslide took place on 01 October 2015 when heavy rains saturated the soil. (Photo by Esteban Biba/EPA)

Spanish matador Juan Jose Padilla looks at a bull during a bullfight at The Maestranza bullring in the Andalusian capital of Seville, southern Spain April 25, 2015. (Photo by Marcelo del Pozo/Reuters)