A walker has left a handprint on a snow- covered tree trunk on Grosser Feldberg mountain in the Taunus mountain range, Germany, 16 January 2017. (Photo by Frank Rumpenhorst/DPA)

A man walks on a bridge crossing over the Besor stream on a rainy day, near Kibbutz Tze'elim in Israel's southern Negev desert February 16, 2017. (Photo by Amir Cohen/Reuters)

Chloe Ferry attends the Geordie Shore series 15 “Shag Pad on Tour” cast launch at Tower Bridge on August 16, 2017 in London, England. (Photo by Karwai Tang/WireImage)

A Somali Armed Forces member carries her ammunition during fighting between the military and police backed by intelligence forces in the Dayniile district of Mogadishu, Somalia September 16, 2017. (Photo by Feisal Omar/Reuters)

An AI Gamer “Q56” robot plays a video game during a demonstration at the Bandai Namco Holdings Inc. booth at the Combined Exhibition of Advanced Technologies in Chiba, Japan on October 16, 2019. (Photo by Kiyoshi Ota/Bloomberg)

Liu Yang, China's first female astronaut, waves during a departure ceremony at Jiuquan Satellite Launch Center, on June 16, 2012. (Photo by Jason Lee/Reuters via The Atlantic)

Craig Jobbins, first buyer of the new iPad to leave the Apple Store, poses for photographers in Covent Garden on March 16, 2012 in London, England. (Photo by Matthew Lloyd/Getty Images)

Children with balloons play beside the statue of British comedy legend Eric Morecambe on January 16, 2012 in Morecambe, England. According to scientists January 16, 2012 was “Blue Monday”, the most depressing day of the year. (Photo by Christopher Furlong/Getty Images)