A staff member demonstrates how she puts on the helmet of a mock space suit at the C-Space Project Mars simulation base in the Gobi Desert outside Jinchang, Gansu Province, China, April 17, 2019. The facility – comprising several interconnected modules including a greenhouse and a mock decompression chamber – opened its doors to the public. (Photo by Thomas Peter/Reuters)

Members of ASC Tornados, the motorcycle display team of the Indian army, lie in a row on the ground as another performs a stunt by jumping over them during the 225th anniversary celebrations of Army Service Corps in Bangalore, India, Tuesday, December 8, 2015. The Army Service Corps which was established in 1790 is an arm of the Indian Army which handles its logistic support function. (Photo by Aijaz Rahi/AP Photo)

A child looks at window cleaners work while dressed in sheep (C) and monkey costumes, denoting animal signs of the Chinese zodiac calendar, during an event marking the upcoming end of the year at a hotel in Tokyo, Japan, December 21, 2015. According to the zodiac calendar, 2015 is the year of the sheep and 2016 is the year of the monkey. (Photo by Thomas Peter/Reuters)

Mr. Zhong Hua, of Johns Hopkins University School of Medicine, took this image of the peripheral nerves (those outside of the brain) in an 11.5-day-old mouse embryo, magnified five times. (Photo by Zhong Hua)

This breathtaking natural light show illuminating waters off the British coast looks like something out of hit film “Close Encounters of the Third Kind”. Photographer Adrian Campfield was out having dinner at a restaurant at Beachy Head, East Sussex, when the rays suddenly appeared. The 59-year-old and his wife Louise rushed outside onto the 535ft high cliffs to watch the spectacle. Mr Campfield, a former graphic designer, from Bexley, Kent, said the light was “changing all the time” for more than 15 minutes. (Photo by Adrian Campfield/Solent/Visual Press Agency)

A man sits waiting for a train on the London Underground in 1890, when the platform floors were still made from wooden floorboards. (Photo by Hi-Story/Alamy Stock Photo)

Elena Chernyshova's vision of Norilsk, Russia, the northernmost city in the world, is a series of surprises by which she extracts otherworldly beauty from ugly realities. Here: 2013. A woman is visible through a narrow passageway between two buildings. Norilsk's urban spaces were designed to shorten distances around large developments and give residents maximum protection from arctic winds. (Photo by Elena Chernyshova)

Austrian Bodybuilder and actor Arnold Schwarzenegger has some fun at a party on a yacht in Marina Del Rey in September 1979 in Los Angeles, California. (Photo by Michael Ochs Archives/Getty Images)