A police officer pepper sprays a protester as another protester stands in front of the race director's car during a farmers' protest who attempted to block the stage' s route, during the 16 th stage of the 105 th edition of the Tour de France cycling race, between Carcassonne and Bagneres- de- Luchon, southwestern France, on July 24, 2018. The race was halted for several minutes on July 24 after tear gas was used as protesting farmers attempted to block the route. (Photo by Stephane Mahe/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)

A pigeon eating cherries in Bydgoszcz, Poland on September 14, 2018. The pigeon was captured at dinnertime, as he was caught on camera with its mouth full of a cherry. (Photo by Piotr Grny/Caters News Agency)

A woman walks on the stairs decorated with an image of two hands shaking to form the shape of the Korean Peninsula to support the upcoming inter- Korean summit, in downtown Seoul on September 17, 2018. South Korean President Moon Jae- in will fly to the North Korean capital on September 18, for his third summit with the North' s leader Kim Jong Un as a rapid diplomatic thaw takes hold on the peninsula despite stalled progress in denuclearisation talks between Pyongyang and Washington. (Photo by Jung Yeon-je/AFP Photo)

Daniel Cheong, a dog behaviorist and trainer, steps over a leash as he walks a pack of dogs in Arlington, Va. on November 13, 2018. (Photo by Ricky Carioti/The Washington Post)

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)

In this October 27, 1983 file photo, soldiers brandish captured AK-47 rifles from the windows of a civilian vehicle as they drive near Point Salines Airport in St. George, Grenada. In 1983, U.S. forces invaded the Caribbean island of Grenada after accusing the government of allying itself with Communist Cuba. (Photo by Doug Jennings/AP Photo)