A wolf looks into the camera at the 30 km (19 miles) exclusion zone around the Chernobyl nuclear reactor in the abandoned village of Orevichi, Belarus, March 2, 2016. What happens to the environment when humans disappear? Thirty years after the Chernobyl nuclear disaster, booming populations of wolf, elk and other wildlife in the vast contaminated zone in Belarus and Ukraine provide a clue. (Photo by Vasily Fedosenko/Reuters)

A man walks with a camel at Birqash camel market on January 27, 2012 in Cairo, Egypt. On the edge of the western dessert, thousands of camels are bought and sold every Friday at Brqash camel market, one of the biggest in the Middle East. (Photo by Jeff J. Mitchell/Getty Images)

A woman walks up the steps decorated ahead of the Chinese New Year festival in Beijing, China, Thursday, January 12, 2017. The Chinese Lunar New Year is the most important holiday for Chinese and hundreds of millions are expected to return to their hometown to spend the new year with their family and relatives. (Photo by Ng Han Guan/AP Photo)

A man walks beside a “Wrinkles Of The City” creation near the Berlin cathedral in Berlin April 19, 2013. (Photo by Fabrizio Bensch/Reuters)

Tianmen Mountain is a mountain located within Tianmen Mountain National Park, Zhangjiajie, in northwestern Hunan Province, China.

SpaceX crews prep the Starship SN8 for its second test engine firing in Boca Chica, TX. on Wednesday, November 11, 2020. SpaceX will try Thursday with 2 engines to be the first ever static fire test to use the LOX header tank. (Photo by Gene Blevins/ZUMA Wire/Rex Features/Shutterstock)

Woman carrying luggage walks along a railway track on the outskirts of Mumbai, India on November 12, 2020. (Photo by Francis Mascarenhas/Reuters)

A woman cools off after taking a traditional steam bath (banya) at Sergei Benke's homestead in the village of Bobrovka, Tarsky District in Omsk Region, Russia on December 11, 2020. (Photo by Sergei Malgavko/TASS)