Dancers at the Windmill Theatre in London, England practice a routine wearing gas masks and hard-hats with their costumes, 1940. (Photo by Hulton Archive/Getty Images)

An Iraq fan poses before the World Cup 2022 Qualifier 2nd round Group C football match between Iraq and Iran at Amman International Stadium in Amman, Jordan on November 14, 2019. (Photo by Muhammad Hamed/Reuters)

An aurora is seen in the sky in Pajala, Sweden on February 10, 2022. (Photo by Alexander Kuznetsov/Reuters)

A person watches the sunrise from the Edge observation deck at Hudson Yards on the first day of spring on March 20, 2021 in New York City. (Photo by Noam Galai/Getty Images)

Sheep stand on a dyke as clouds cover the sky over Tossens, northern Germany, on September 2, 2019. (Photo by Mohssen Assanimoghaddam/dpa/AFP Photo)

National Guardsmen are put through riot training in Boston's Commonwealth Armory on Friday, October 18, 1974. Massachusetts Gov. Francis W. Sargent called up the guard to quell school violence, but the city has been relatively calm and the guard has remained in the armories. (Photo by JWG/AP Photo)

Aeroflot employees with a puppy at the canine service of Aeroflot at Sheremetyevo International Airport in Moscow Region, Russia on October 2, 2020, that has started to train service dogs to detect COVID-19 in people. (Photo by Vladimir Gerdo/TASS)

In this artist's impression supplied by the ESO (European Southern Observatory) on April 25, 2007, the planetary system around the red dwarf, Gliese 581, is pictured showing what astronomers believe is the most earth like planet found outside our solar system to date. Using the ESO 3.6-m telescope in Chile, astronomers have uncovered the planet which could have water running on its surface. The planet orbits the faint star Gliese 581, which is 20.5 light-years away in the constellation Libra. (Photo by ESO via Getty Images)