People on inflatable boats enjoy the weather on the Lake Lucerne in Sisikon, Switzerland, August 5, 2018. (Photo by Denis Balibouse/Reuters)

In this Friday, December 4, 2018 photo, a half sunken cruise ship lays on its side, in the Gulf of Elefsina, west of Athens. Dozens of abandoned cargo and passenger ships lie semi-submerged or completely sunken around the Gulf of Elefsina, near Greece’s major port of Piraeus. Now authorities are beginning to remove the dilapidated ships. Some of them have been there for decades, leaking hazards like oil into the environment and creating a danger to modern shipping. One expert calls the abandoned ships “an environmental bomb”. (Photo by Thanassis Stavrakis/AP Photo)

The Aurora Borealis (Northern Lights) lights up the sky near the village of Pallas (Muonio region) of Lapland, Finland September 8, 2017. (Photo by Alexander Kuznetsov/Reuters/All About Lapland)

North Korean traffic police women chat next to a residential building while off duty Tuesday, October 18, 2016, in Pyongyang, North Korea. (Photo by Wong Maye-E/AP Photo)

Life-size sеx dolls are displayed during the 2016 AVN Adult Entertainment Expo at the Hard Rock Hotel & Casino on January 20, 2016 in Las Vegas, United States. (Photo by Gabe Ginsberg/FilmMagic)

M42 Subtle V1 cropped. One of the most well-known astronomical objects in our universe is the Orion Nebula and this image depicts the wider region of the Orion Molecular Cloud Complex that is its home. This complex also includes another popular target for astrophotographers, the Horsehead Nebula, as well as Barnard’s Loop and the Running Man Nebula, which can be seen to the left of this photograph. (Photo by Patrick Gilliland)

Participants run through the streets of the Back Bay during the 16th annual Santa Speedo Run in Boston, Massachusetts, December 12, 2015. (Photo by Brian Snyder/Reuters)

Two Inuit children at Point Barrow, Alaska, holding the tusks of a large walrus, probably killed for food, circa 1930. (Photo by General Photographic Agency/Getty Images)