A pilot inflates a hot air balloon while taking part in the 38th International Balloon Festival of Chateau-d'oex, Switzerland, 23 January 2016. The festival takes place from 23 to 31 January. (Photo by Vincent Vannay/EPA)

A coach wipes away tears and comforts a girl who was feeling tired during gymnastics lessons at the Shanghai Yangpu Youth Amateur Athletic School in Shanghai, China, May 4, 2016. (Photo by Aly Song/Reuters)

Commuters hang off a local passenger train in the morning in Colombo, Sri Lanka September 8, 2016. (Photo by Dinuka Liyanawatte/Reuters)

A guard stands at Dityatki checkpoint, marking a 30 km (18-mile) zone around the Chernobyl nuclear power plant April 23, 2013. Ukraine will mark the 27th anniversary of the Chernobyl disaster, the world's worst civil nuclear accident, on April 26. (Photo by Gleb Garanich/Reuters)

The Aurora Borealis (Northern Lights) is seen over the sky near Inari in Lapland, Finland on February 14, 2019. (Photo by Alexander Kuznetsov/Reuters)

Performers on boats take part in the Qintong Boat Festival at Qin Lake National Wetland Park on April 6, 2019 in Taizhou, Jiangsu Province of China. The boat festival is held around the Qingming Festival every year, and up to 10,000 participants from nearby villages and towns, with more than 500 boats, took part in the event this year. (Photo by Tang Dehong/VCG via Getty Images)

Moruti Mthalane of South Africa is punched by Masayuki Kuroda of Japan during their IBF flyweight title boxing bout in Tokyo on May 13, 2019. (Photo by Charly Triballeau/AFP Photo)

Luke Jerram's “Museum of the Moon” at English Heritage's Illuminating Rievaulx installation at Rievaulx Abbey, near Helmsley, North Yorkshire, England on September 18, 2019. (Photo by Danny Lawson/PA Images via Getty Images)