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)

Swedish climate change activist Greta Thunberg, Isabelle Axelsson and German Luisa Neubauer take part in a climate strike protest during the 50th World Economic Forum (WEF) annual meeting in Davos, Switzerland on January 24, 2020. (Photo by Denis Balibouse/Reuters)

Victoria Sinitsina and Nikita Katsalapov of Russia perform during Gala exhibition skating program of the ISU European Figure Skating Championships in Graz, Austria, 26 January 2020. (Photo by Tatyana Zenkovich/EPA/EFE)

A resident pulls back a rope with groceries tied to the end of it, delivered by community workers, at a residential compound under sealed management in Yichang, Hubei province, China on February 22, 2020. (Photo by Reuters/China Daily)

The comet Neowise, or C/2020 F3, is seen in the evening sky above the artwork titled: “Seven Magic Mountains” by artist Ugo Rondinone, Thursday, July 16, 2020, near Jean, Nev., south of Las Vegas. (Photo by John Locher/AP Photo)

North Korean bodyguards run along a limousine transporting Kim Jong Un upon his arrival in Dong Dang, Vietnam, February 26, 2019. The second meeting of the US President and the North Korean leader, running from 27 to 28 February 2019, focuses on furthering steps towards achieving peace and complete denuclearization of the Korean peninsula. (Photo by Reuters/Stringer)

A street artist makes soap bubbles in front of the Alte Nikolaikirche church at the Roemerberg square in Frankfurt am Main, western Germany, on August 12, 2018. (Photo by Frank Rumpenhorst/DPA/AFP Photo)

Olympe, the latest creation by artist Aspencrow, is unveiled at JD Malat gallery in London, England on March 27, 2019. It is a sculpture of Cara Delevingne based on the Greek mythological monster Medusa. (Photo by Anthony Harvey/Rex Features/Shutterstock)