“A fter the former Soviet Union conducted its first nuclear test in August 1949, the US reevaluated its postwar defense policies. With the US monopoly on atomic weapons broken, military and political leaders chose to diversify the American stockpile by developing thermonuclear and tactical nuclear weapons. One of the more interesting concepts to come out of this period was atomic artillery, which was successfully tested at the Nevada Proving Grounds (now the Nevada Test Site) in May 1953”. – Alan Carr. Photo: Atomic Annie at work during the Upshot-Knothole test series, 1953. (Photo by Los Alamos National Laboratory/US Army)

Police officers clear the area near Borough market at London Bridge on June 3, 2017 in London, England. Police have responded to reports of a van hitting pedestrians on London Bridge in central London. (Photo by Dan Kitwood/Getty Images)

A motorcycle carrying protesters holding a placard using the acronym of the national electoral commission, drives ahead of demonstrators on foot calling for the disbandment of the commission over allegations of bias and corruption, in downtown Nairobi, Kenya Monday, June 6, 2016. (Photo by Ben Curtis/AP Photo)

Protesters hold on to each other as they are sprayed with water from police water cannons in Martyr square, downtown Beirut, Lebanon October 8, 2015. Lebanese security forces fired tear gas and water cannons to break up an anti-government protest in Beirut on Thursday, and the country's fractious leaders postponed talks aimed at resolving a political crisis that is feeding public discontent. (Photo by Aziz Taher/Reuters)

Pistachio, a puppy who was born with green fur, is seen on the day he was born on a farm on the island of Sardinia, in Pattada, Italy, October 9, 2020. (Photo by Cristian Mallocci/Handout via Reuters)

A brig with scarlet sails travels on the Finnish Gulf coast during a rehearsal for the the Scarlet Sails festivities marking school graduation in St. Petersburg, Russia, early Saturday, June 27, 2020. This year the festival will not be held in the city center, but on the Finnish Gulf. Due to the coronavirus pandemic, there will be no spectators but the event will be broadcast on television. (Photo by Dmitri Lovetsky/AP Photo)

Overall winner: The Art of Flight by Alwin Hardenbol (University of Eastern Finland). A panning shot of a Dalmatian pelican in flight. The picture was taken on Lake Kerkini in Greece. (Photo by Alwin Hardenbol/2020 British Ecological Society Photography Competition)

Relatives of inmates of the «Santiago 1» jail react outside the prison after a large number of prisoners attempted to escape amid panic over the spread of the COVID-19 coronavirus in Santiago, Chile, on March 19, 2020. (Photo by Javier Torres/AFP Photo)