Students wearing mask hold hands to surround the St. Stephen's Girls' College in Hong Kong, Monday, September 9, 2019. Thousands of demonstrators in Hong Kong urged President Donald Trump to “liberate” the semiautonomous Chinese territory during a peaceful march to the U.S. Consulate on Sunday, but violence broke out later in the business and retail district as police fired tear gas after protesters vandalized subway stations, set fires and blocked traffic. (Photo by Kin Cheung/AP Photo)

Aurora Australis from Beerbarrel Beach, by James Stone. Runner Up: Aurorae. (Photo by James Stone/Astronomy Photographer of the Year)

A praying mantis, a huddle of butterflies, Galician horses and an alpine sunset are the winners of this year’s European Environment Agency’s “Rediscover Nature” photo competition. Here: Nature on My Doorstep, finalist. I Want That Pomerade Grain by Biagio Alberto Scalia, taken in national park of Circeo, Latina, Italy. (Photo by Biagio Alberto Scalia/REDISCOVER Nature/EEA)

A bird flies over the abandoned giant sculpture of a Buddhist monk in Cha-am outside Hua Hin, 145km south of Bangkok, on February 25, 2021. (Photo by Mladen Antonov/AFP Photo)

A man and his cat rest in the street after an earthquake on May 22, 2021 in Dali, Yunnan Province of China. According to the China Earthquake Networks Center, a 5.6-magnitude earthquake jolted Yangbi Yi autonomous county in Dali Bai autonomous prefecture, Southwest China's Yunnan province on Friday evening. (Photo by Liu Ranyang/China News Service via Getty Images)

Aurorae category runner-up: Lone Tree under a Scandinavian Aurora by Tom Archer (UK). The photographer decided to explore the area around the hotel on a very crisp -35C evening in Finnish Lapland. When he found this tree, he decided to wait for the misty conditions to change and could not believe his luck when the sky cleared and the aurora came out in the perfect spot. Archer spent about an hour photographing it before his camera started to lock up because of the harsh conditions, but by then he was happy to call it a night. (Photo by Tom Archer/2020 Astronomy Photographer of the Year)

Amateur astronomer Bill Snyder has been involved with astrophotography since 2007. Photo: The Cygnus Wall is in the southern area of NGC7000 also known as the North America Nebula. It is approximately 1800 light years from Earth, and is in the constellation Cygnus. The Wall is an energized shock front and contains the most concentrated star formations in the nebula. The size of the North America Nebula is about 4 full moons. (Photo and caption by Bill Snyder)

Young category winner. Great autumn morning by Fabian Dalpiaz. (Photo by Fabian Dalpiaz/2018 Astronomy Photographer of the Year)