A couple covered in mud wait for it to dry at the Salt-works lakes near the Black Sea town of Burgas in Bulgaria on July 25, 2019. Thousands of tourists visit the red salt lakes for mud baths, which are believed to help the healing of muscular disorders and rheumatism. (Photo by Nikolay Doychinov/AFP Photo)

A three-metre-tall painted bronze sculpture, Seated Man 2016, by the artist Sean Henry, is lifted into its new home on July 23, 2019 at Yorkshire Sculpture Park in Wakefield, England. (Photo by Christopher Thomond/The Guardian)

A zoo keeper carries a pelican to move it to its winter enclosure at Dvur Kralove Zoo in Dvur Kralove nad Labem, Czech Republic on November 5, 2019. (Photo by David W. Cerny/Reuters)

Tightrope walker Tatian-Mosio Bongonga hangs from a tightrope as she pauses while scaling the Monmartre hill towards the Sacre Coeur Basilica (not pictured) in Paris, France, July 20, 2018. (Photo by Philippe Wojazer/Reuters)

A handout photo made available by the NASA shows the United Launch Alliance Delta IV Heavy rocket launches NASA's Parker Solar Probe to touch the Sun, from Launch Complex 37 at Cape Canaveral Air Force Station, Florida, USA, 12 August 2018. Parker Solar Probe is humanity’s first-ever mission into a part of the Sun’s atmosphere called the corona. Here it will directly explore solar processes that are key to understanding and forecasting space weather events that can impact life on Earth. (Photo by Bill Ingalls/EPA-EFE/NASA)

Steam rises from Lake Superior as the ship St. Clair comes to harbor during some of the coldest temps of the year, Sunday, December 31, 2017, at Canal Park in Duluth, Minn. The St. Clair is a self-unloader built in 1976 at Sturgeon Bay, Wis., and is 770 feet long and has 26 hatches that open into 5 cargo holds, providing a load capacity of 45,000 tons. (Photo by David Joles/Star Tribune via AP Photo)

A ranger watches a seal pup near the Northumberland coast, Farne Islands, UK on December 19, 2018, where the National Trust says the number of Atlantic grey seal pups has reached a record high thanks to an abundance of food and a lack of predators. (Photo by Owen Humphreys/PA Wire Press Association)

A person participates in the parade of the “San Jose Carnival” in San Jose, Costa Rica, 27 December 2018. The festival sees people parading through the city's main avenues as part of the San Jose Celebrations that take place at the end of each year. (Photo by Jeffrey Arguedas/EPA/EFE)