New York City policemen tangled with demonstrators at a subway station on the opening day of the New York World's Fair, April 22, 1964. Youths attempted to stall the train, which was headed from the city to the fairgrounds, as a form of protest on behalf of civil rights for blacks. (Photo by Charles Gorry/AP Photo)

Timbuktu: A UN peacekeeper from Burkina Faso stands guard at the Djinguereber mosque, built in the 14th century, during a visit by a UN delegation on election day in Timbuktu, Mali, July 28, 2013. (Photo by Joe Penney/Reuters)

A reveler jumps over a bonfire during the night of San Juan in Alcobendas near Madrid, Spain, Wednesday, June 24, 2015. The San Juan night coincides with the Summer solstice and it's the welcome to Summer. This celebration takes place during the shortest night of the year in almost all cities and towns of Spain. (Photo by Andres Kudacki/AP Photo)

Pan Am aircraft – here in 1963 with the abbreviation PAA for Pan Am Airways – could be seen everywhere, including from the freeway in New York before the Strato Clipper took off for Europe in 1963. (Photo by Imago)

An undated handout photo made available by the Zerynthia Association shows the pupa of an amicta moneiba, a recently discovered species of moth endemic to La Gomera and El Hierro islands in the Canary Islands, Spain (issued 01 July 2020), as those two islands pulled apart from the rest of the Canary Islands 2.5 million years ago. The Institute of Evolutionary Biology of the Spanish National Research Council (CSIC) and the Zerynthia Association have recently discovered two new moth species in El Hierro and La Gomera. (Photo by Yeray Monasterio/Zerynthia/EPA/EFE)

A voter wearing protective face mask shows off her finger marked with ink indicating she voted as she leaves a polling station Sunday, November 8, 2020, in Yangon, Myanmar. Voting was underway in Myanmar’s elections on Sunday, with the party of Nobel Peace Prize laureate Aung San Suu Kyi heavily favored to retain power it had wrestled from the powerful military five years ago. (Photo by Thein Zaw/AP Photo)

A Humboldt penguin swims in a pool during the annual stock take at ZSL London Zoo in London, Thursday, January 2, 2020. Caring for more than 500 different species, ZSL London Zoo's keepers face the challenging task of tallying up every animal large and small, every mammal, bird, reptile, fish and invertebrate at the Zoo. (Photo by Frank Augstein/AP Photo)

Emily Ratajkowski and Vanessa Hudgens attend the 73rd Annual Tony Awards at Radio City Music Hall on June 09, 2019 in New York City. (Photo by Mike Coppola/Getty Images for Tony Awards Productions)