A participant dressed as a mermaid goes to swim in the beach after taking part in the Annual Mermaid Parade in Brooklyn, New York, June 18, 2016. The annual parade, founded in 1983, seeks to bring mythology to life for residents, create confidence in the district and to allow artistic self-expression in public, according to the parade's website. (Photo by Eduardo Munoz/Reuters)

Goose, a nine-month-old cat, sits in a backpack as people gather during a Speak Out Against Sexual Violence demonstration at Eastern Michigan University in Ypsilanti, Michigan, U.S., March 28, 2021. (Photo by Emily Elconin/Reuters)

Picture made available by “All About Lapland” on March 24, 2023 and taken on on late March 23, 2023 shows colourful northern lights (Aurora borealis) appearing around the Arctic Circle near Rovaniemi, Finland. The northern lights appeared right after dawn, and they continued all the way through the night. (Photo by Alexander Kuznetsov/All About Lapland/AFP Photo)

Mae Muller of the United Kingdom performs during dress rehearsals at the Eurovision Song Contest in Liverpool, England, Wednesday, May 10, 2023. (Photo by Martin Meissner/AP Photo)

A Goodfellow's Tree Kangaroo joey with its mother at Sydney Zoo in Australia on January 22, 2021. The 28-week-old male joey, who is yet to be named, has only just begun to pop his head and shoulders out of his mum's pouch. (Photo by Taronga Zoo via Reuters)

Fresh produce and baskets of fish surround a woman at the Siti Khadijah market in Kota Bharu, Malaysia. (Photo by Duratul Ain D.)

“Hippo Chase”. As we approached the camp the Selinda Reserve of northern Botswana our boat passed by a hippo resting in the water. I turned around to look back at the boat's wake and saw the hippo charging after us! The hippo must've been tired from an all-nighter because he was angry. He rose way up out of the water three times trying to chase our boat! He was coming at us with such force that he created a wake of his own. Photo location: Selinda Reserve of northern Botswana. (Photo and caption by Curtis Simmons/National Geographic Photo Contest)

The competition is run by Royal Observatory Greenwich sponsored by Insight Investment and in association with BBC Sky at Night Magazine. This year astrophotographers from 91 countries sent in more than 4,200 spectacular entries. Here: The Milky Way rises above an isolated lighthouse in Tasmania. Shot by James Stone of Australia. (Photo by James Stone/Astronomy Photographer of the Year 2018)