Flying pigeons pass over Nepalese street vendors near the earthquake damaged UNESCO World Heritage Site, Durbar Square in Kathmandu on May 20, 2015. Nearly 8,500 people have now been confirmed dead in the disaster, which destroyed more than half a million homes and left huge numbers of people without shelter with just weeks to go until the monsoon rains. (Photo by Ishara S. Kodikara/AFP Photo)

The northern lights, or aurora borealis, appear in the sky over the Bamburgh lighthouse at Stag Rock in Northumberland, England on September 28, 2016. (Photo by Owen Humphreys/PA Wire via ZUMA Press)

A combination photo shows the faces of various attendees of New York Comic Con in Manhattan, New York, October 8, 2015. The event draws thousands of costumed fans, panels of pop culture luminaries and features a sprawling floor of vendors in a space equivalent to more than three football fields at the Jacob Javits Convention Center on Manhattan's West side. (Photo by Andrew Kelly/Reuters)

A calico sits in its enclosure and suns itself in Hessen, Germany on May 28, 2021. The Opel Zoo presents a walk-in Madagascar aviary for caltas and varis. The primate species is native to Madagascar and is threatened with extinction. (Photo by Andreas Arnold/dpa)

People watch as an acrobat rides his motorcycle around a circular track at an entertainment park set up outside a shrine in Rawalpindi, Pakistan, on June 19, 2013. (Photo by Muhammed Muheisen/Associated Press)

A pink elephant balloon, one of the entries in the Canadian Hot Air Balloon Championships, lands in a field in High River September 27, 2013. The event is a qualifier for the World Hot Air Balloon Championships in Sao Paulo in 2014. (Photo by Mike Sturk/Reuters)

A Vietnamese woman, wearing the traditional “ao dai” long dress, poses for photos along peach blossom flowers ahead of the Vietnamese “Tet” (Lunar New Year festival), in a field in Hanoi, Vietnam, February 2, 2016. (Photo by Reuters/Kham)

Party-goers partake in a festival better known as Holi One, during International Workers Day in Johannesburg, South Africa, 01 May 2015. The colour festival promotes togetherness as well as colourness in everday life. May Day is observed worldwide every year on 01 May. (Photo by Kevin Sutherland/EPA)