The competition, which is run by the Royal Observatory Greenwich in association with BBC Sky at Night Magazine, is now in its sixth year and has received over 2,500 entries. Photo: Centre of the Heart Nebula by Ivan Eder (Hungary). Situated 7500 light years away in the “W”-shaped constellation of Cassiopeia, the Heart Nebula is a vast region of glowing gas, energized by a cluster of young stars at its centre. The image depicts the central region, where dust clouds are being eroded and moulded into rugged shapes by the searing cosmic radiation. (Photo by Ivan Eder)

Participants in the 3rd Annual Amber Rose SlutWalk in Los Angeles, California. October 1, 2017. The event seeks to highlight issues such as: gender equality, ending rape culture, victim blaming and body shaming. (Photo by Ronen Tivony/NurPhoto via Getty Images)

A follower of the Afro-Brazilian religion Umbanda pays tribute for Iemanja, goddess of the sea, in Copacabana Beach in Rio de Janeiro, Brazil December 29, 2017. Hundreds of practitioners of Brazil's Afro-Brazilian Candomble and Umbanda faiths have gathered at Rio de Janeiro's Copacabana beach to honor Yemanja. Worshippers were mostly dressed in white as they launched their offerings to Iemanja: small boats with flowers and bowls with candles and fruits. (Photo by Ricardo Moraes/Reuters)

Women jump into the water during a traditional New Year bath in the Adriatic sea in Portoroz, Slovenia on January 1, 2018. (Photo by Jure Makovec/AFP Photo)

A squid swims underwater off the shore of the coastal city of Qalamun, north of the Lebanese capital Beirut, on September 24, 2019. (Photo by Ibrahim Chalhoub/AFP Photo)

Revellers help a man crowdsurf as they watch The Slaves perform on The Other Stage at the Glastonbury Festival of Music and Performing Arts on Worthy Farm near the village of Pilton in Somerset, South West England, on June 30, 2019. (Photo by Oli Scarff/AFP Photo)

A demonstrator is detained by riot police during a protest, in La Paz, Bolivia on November 21, 2019. Bolivia's interim President Jeanine Anez asked Congress Wednesday to approve a law that would allow for new elections, after deadly unrest following the resignation of Evo Morales and the disputed October 20 ballot. (Photo by Marco Bello/Reuters)

The Invasion. A quiet street in Macau. Modernization around is quickly changing the city, as documented by Paul Tsui. (Photo by Paul Tsui/National Geographic Travel Photographer of the Year Contest)