A pilot looks up from a U.S. F-22 Raptor fighter as it prepares to refuel in mid-air with a KC-135 refuelling plane over European airspace during a flight to Britain from Mihail Kogalniceanu air base in Romania April 25, 2016. (Photo by Toby Melville/Reuters)

A woman jumps with balloons while she poses for a picture at a park in Kiev, Ukraine May 6, 2018. (Photo by Valentyn Ogirenko/Reuters)

Split-view of a killer whale at sunrise off the coast of Northern Norway. At least half of the world’s killer whale populations are doomed to extinction due to pollution of the oceans, a new study says. (Photo by Audun Rikardsen/Science)

“Oak Sunrise” by professional photographer Alan Price has won the International Garden Photographer of the Year, “Celebrating Our Oaks” competition, run in partnership with Action Oak. Action Oak is a campaign to protect the UK’s oak trees from threats including pests and diseases. (Photo by Alan Price/IGOTY)

Secondary school graduates play in a fountain as they celebrate the last day of school, traditionally called the “last bell” in central Kiev, Ukraine on May 31, 2019. (Photo by Valentyn Ogirenko/Reuters)

This picture taken on May 24, 2019 shows Mariam the dugong as she is cared for by park officials and veterinarians from the Phuket Marine Biological Centre on Libong island, Trang province in southern Thailand. An orphaned baby dugong rescued off a beach in Krabi province is Thailand's newest star, capturing the hearts of millions on social media and igniting an awarness for ocean conservation as authorities hand-raise the young mammal. (Photo by Sirachai Sirachai Arunrugstichai/AFP Photo)

An aircraft passes the rising sun during take off at the international airport in Frankfurt, Germany, Monday, September 2, 2019. (Photo by Michael Probst/AP Photo)

Alien-themed decorations are seen at the Alien Research Center in Hiko, September 19, 2019. Scores of UFO enthusiasts converged on rural Nevada for a pilgrimage of sorts to the U.S. installation known as Area 51, long rumored to house government secrets about alien life, as law enforcement officials beefed up security around the military base. (Photo by Jim Urquhart/Reuters)