In this June 6, 1966 file photo, civil rights activist James Meredith pulls himself across Highway 51 after being shot in Hernando, Miss. Meredith, who defied segregation to enroll at the University of Mississippi in 1962, completed the march from Memphis, Tenn., to Jackson, Miss., after being treated for his wounds. (Photo by Jack Thornell/AP Photo)

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)

A woman holds up the Chinese national flag as people gather to watch the the launch of the Long March 5B rocket carrying China's Tianhe space station core module from the Wenchang Spacecraft Launch Site in Hainan Province, China, 29 April 2021. China launched into space the core module of its space station, marking the beginning of a series of launch missions to complete the space station by the end of next year. (Photo by Matjaz Tancic/EPA/EFE)

A cadet lies on the grass after collapsing during a promotion ceremony at a police school in Bogota December 7, 2012. (Photo by John Vizcaino/Reuters)

An airplane passes the moon as it makes its approach to Philadelphia International Airport, Sunday, September 7, 2014, in Philadelphia. (Photo by Matt Rourke/AP Photo)

The Yakutat Glacier is seen during a flight over southeastern Alaska near the town of Yakutat, October 7, 2014. (Photo by Bob Strong/Reuters)

A walruses at Hagenbeck Zoo in Hamburg, Germany on July, 7, 2015. (Photo by Werner Struss/Startraks action)

A keeper stands next to llamas during the Annual Stocktake at ZSL London Zoo in London, Britain February 7, 2018. (Photo by Tom Jacobs/Reuters)