A woman runs through the early morning mist on Hampstead Heath on September 30, 2011 in London, England. Much of the UK is enjoying a spell of unseasonably hot weather which is expected to last into next week. (Photo by Dan Kitwood/Getty Images)

A child stands inside a large soap bubble made by a street artist at the Mayor square in central Madrid, Friday, December 9, 2016. (Photo by Francisco Seco/AP Photo)

In this photo provided by Andreas Langreiter via Global-Newsroom, Hannes Arch of Austria performs during the finals of the first stage of the Red Bull Air Race World Championship in Abu Dhabi, United Arab Emirates, Saturday, February 14, 2015. (Photo by Andreas Langreiter/AP Photo/Global-Newsroom)

Four pillars of light from the 4 Laser Guide Star Facility on ESO's Very Large Telescope (VLT) are shown reaching into the Chilean night sky in this image from ESO Photo Ambassador Fred Kamphues, on September 2, 2016. The lasers are a key part of the adaptive optics system on the VLT. Adaptive optics allows astronomers to drastically reduce the atmospheric distortion present at even the best sites in the world for astronomy, including Paranal in Chile, the home of the VLT. (Photo by F. Kamphues/ESO)

In this Sunday, March 5, 2017, photo, hospitality staff take souvenir photos in front of the Great Hall of the People where the National People's Congress is held in Beijing. (Photo by Andy Wong/AP Photo)

Students training to be flight attendants hold books on their heads, chopsticks in their mouths, and papers in between their knees, as they take part in a standing posture practice at a vocational school in Shijiazhuang, Hebei province, China May 4, 2017. (Photo by Reuters/Stringer)

Machu Picchu, Peru. A llama’s-eye view of the legendary Inca settlement at Machu Picchu, isolated high in the Peruvian Andes. (Photo by Jim Turner/National Geographic)

An adult specimen of Nannospalax (leucodon) montanosyrmiensis, a variant of the lesser mole-rat (Spalax leucodon) is pictured near Albertirsa, some 60 kilometers southeast of Budapest, Hungary, 12 May 2018. The critically endangered rodent lives in several isolated populations in the Carpathian Basin. (Photo by Sandor Ujvari/EPA/EFE)