High-rise buildings are partly covered by heavy fog at Hong Kong's Victoria Harbour Monday, March 20, 2017. Fog blanketing Hong Kong is common in springtime and may greatly affect shipping and aviation. (Photo by Vincent Yu/AP Photo)

Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

Boys ride a motorbike on their way back home after taking a bath in a canal at Chachura village, in Uttar Pradesh April 4, 2012. (Photo by Parivartan Sharma/Reuters)

Handler Jorge Garcia-Bengochea holds Honor, a miniature therapy horse from Gentle Carousel Miniature Therapy Horses, as they visit with patients at the Kravis Children's Hospital at Mount Sinai in the Manhattan borough of New York City, March 16, 2016. Some of the most powerful medicine delivered to young patients at Mount Sinai Hospital in New York on Wednesday came in a package less than 32 inches tall and with a tail. Honor, a 10-month-old colt with Gentle Carousel Miniature Therapy Horses, trotted into the hearts of dozens of children and teens being treated at the Manhattan hospital. (Photo by Mike Segar/Reuters)

A young Afghan vendor waits for customers to buy sheep's heads at a roadside stall at the busy market in Kabul on November 29, 2015. (Photo by Wakil Kohsar/AFP Photo)

A model is groomed backstage of the Fashion East catwalk show during London Fashion Week Spring/Summer 2017 in London, Britain September 17, 2016. (Photo by Neil Hall/Reuters)

A bird stands near people waiting on South Padre Island to watch the SpaceX Starship rocket launch from Starbase, Texas, on May 27, 2025. SpaceX mission control lost contact with the upper stage of Starship as it leaked fuel, spun out of control, and made an uncontrolled reentry after flying halfway around the world, likely disintegrating over the Indian Ocean, officials said. (Photo by Sergio Flores/AFP Photo)

Jason Garcia poses as The Joker from Batman at the 2015 Comic-Con International in San Diego, California, July 9, 2015. (Photo by Sandy Huffaker/Reuters)