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)

Amundsen-Scott South Pole Station experiences months of darkness. The sun dips below the horizon on March 21, after which follows several weeks of twilight before complete darkness results. Photo taken on June 25, 2009. (National Science Foundation/Jeremy Johnson)

Miners pulling up lazy tourists to the rim of Kawah Ijen (Ijen Volcano), East Java, Indonesia on September 21, 2017. They will earn as much as they would bring down a load of sulfur. Nomadic Explorer, Cultural Lifestyle Photographer Claudio Sieber captured striking images of miners working at Ijen volcanic range in East Java, Indonesia. The sulphur miners risk their lives daily as they climb the active volcano carrying heavy loads, which they sell to sugar refineries. (Photo by Claudio Sieber/Barcroft Images)

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)

North Korean cheerleaders arrive at a rest stop, or service station, as their bus convoy carrying a 280- member delegation on its way to the 2018 Pyeongchang winter Olympic games, makes its way past Gapyeong on February 7, 2018 More than 200 young North Korean women arrived in South Korea to root for athletes from both sides of the peninsula at the Winter Olympics. (Photo by Ed Jones/AFP Photo)

Family members mourn the passing of Manuela Chavez, who died from symptoms related to the new coronavirus at the age of 88, as a government team prepares to remove her body from inside her home, in the Shipibo Indigenous community of Pucallpa, in Peru's Ucayali region, Monday, August 31, 2020. While the lucky are cured with ancestral ailments, the less fortunate often die at home. A government team travels from one spartan, thatch-roofed home to the next, removing the dead from their homes where they took their last breaths. (Photo by Rodrigo Abd/AP Photo)