The Northern Lights glow green in a spectacular light show above a field of trees frozen solid with snow. (Photo by Jaak Sarv/Solent News & Photo Agency)

Performers line up during the closing ceremony of the 2014 Winter Olympics, Sunday, February 23, 2014, in Sochi, Russia. (Photo by Darron Cummings/AP Photo)

A brushtail possum whose ears and legs have been burnt from recent bushfires sits in a cage before being transported to a wildlife hospital, in Batemans Bay, South of Sydney, Australia, 14 January 2020. (Photo by Steven Saphore/EPA/EFE)

In this April 20, 2018, file aerial photo released by China's Xinhua News Agency, advection fog drifts across skyscrapers on the waterfront in Qingdao in eastern China's Shandong Province. Chinese leaders have long been sensitive about their communist country’s international image. Now, they are battling back, investing in diplomacy and a courtship of hearts and minds, just as the United States digs in on the Trump administration’s “America First” mindset. (Photo by Lu Hui/Xinhua via AP Photo/File)

Yeshiva School students briefly dance on Grant Street after the menorah lighting outside of the City-County Building for the fifth night of Hanukkah, Thursday, December 26, 2019, in downtown Pittsburgh. (Photo by Alexandra Wimley/Pittsburgh Post-Gazette via AP Photo)

Members of Tom Maior Special Group samba school perform during the carnival parade at the Anhembi Sambadrome in Sao Paulo, Brazil, 22 Febr​uary 2020. Carnival is the biggest and most popular celebration in Brazil. (Photo by Sebastiao Moreira/EPA/EFE)

A man sets himself on fire during protest rallies in front of the presidential office in Kiev, Ukraine on February 26, 2020. The man, who called himself Oleksandr Burlakov, said subsequently that his motive was to draw the attention of the authorities to his plight, related to the ownership of the land parcel. (Photo by Ihor Behus/Reuters)

A person stands next to the skyline of lower Manhattan on the opening day the Edge NYC, an outdoor observation deck on the 100th floor of 30 Hudson Yards on March 11, 2020 in New York City. (Photo by Gary Hershorn/Getty Images)