Riot police wear face masks, as a precautionary measure against the COVID-19 coronavirus, allow a women to cross a cordon after a protest by pro-democracy demonstrators at a shopping mall in Hong Kong on May 9, 2020. (Photo by Isaac Lawrence/AFP Photo)

An Israeli police officer holds his weapon as he stands in front of an injured Israeli driver moments after witnesses said his car crashed into a Palestinian on a pavement during stone-throwing clashes near Lion's Gate just outside Jerusalem's Old City on May 10, 2021. (Photo by Ilan Rosenberg/Reuters)

A Romanian honor guard soldier stands still as three military aircraft carriers are crossing the sky during a ceremony held at the Unknown Soldier Memorial, in Carol I Park, on the occasion of the Heroes' Day commemoration, in Bucharest, Romania, 10 June 2021. (Photo by Robert Ghement/EPA/EFE)

Women holding the Singapore national flag pose for a photograph at the Merlion Park to mark the 55th National Day celebrations in Singapore on August 9, 2020. National Day is celebrated in commemoration of Singapore's independence from Malaysia in 1965. (Photo by Roslan Rahman/AFP Photo)

Teachers and students of dance schools dance maintaining social distance in Barcelona, Spain on November 9, 2020 during a protest against harsher anti-covid19 measures as closures in the hospitality and culture sector and limitations of social contacts by the Catalan government due to the accelerated spread of the coronavirus. (Photo by Matthias Oesterle/ZUMA Wire/Rex Features/Shutterstock)

Russian President Vladimir Putin, right, and North Korea's leader Kim Jong Un pose for photographers during their meeting in Vladivostok, Russia, Thursday, April 25, 2019. Putin and Kim are set to have one-on-one meeting at the Far Eastern State University on the Russky Island across a bridge from Vladivostok. The meeting will be followed by broader talks involving officials from both sides. (Photo by Alexander Zemlianichenko/AP Photo/Pool)

“Aurora Hunters”. Photographers taking part in a photography tour on the Lofoten Islands in Norway, pull over on the side of the road to take a photo of their first ever Aurora Borealis after spotting it from their tour bus. Photo location: Rystad, Lofoten Islands, Norway. (Photo and caption by Mark Gee/National Geographic Photo Contest)