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)

Women dressed in folk costumes take part in a traditional wedding ceremony in the village of Galicnik, west of Macedonia's capital Skopje, July 12, 2014. The Galicnik Wedding, a three-day traditional Macedonian wedding celebration held each “Petrovden” or St. Peter's Day, involves traditional customs, costumes, and rituals and dances that have been passed down over the centuries. (Photo by Ognen Teofilovski/Reuters)

An artwork entitled “Are you still mad at me?” by John Isaacs is displayed at the Death: A Self-portrait exhibition at the Wellcome Collection on November 14, 2012 in London, England. The exhibition showcases 300 works from a unique collection by Richard Harris, a former antique print dealer from Chicago, devoted to the iconography of death. The display highlights art works, historical artifacts, anatomical illustrations and ephemera from around the world and opens on November 15, 2012 until February 24, 2013. (Photo by Peter Macdiarmid)

A motorcycle carrying a pig crosses a flooded road in Albay province, central Philippines due to Typhoon Vamco on Thursday, November 12, 2020. (Photo by John Michael Magdasoc/AP Photo)

Iranian girls wearing face masks walk in Tehran, Iran, 02 November 2020. According to the Iranian Health ministry, Iran reported its highest daily COVID-19 death toll and infections by announcing 440 deaths and 8,289 new infections in past 24 hours in what appears to be a third wave of COVID-19 outbreak. (Photo by Abedin Taherkenareh/EPA/EFE)

Law enforcement officers detain a man during a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Russia on January 31, 2021. Thousands of people have taken to the streets across Russia to demand the release of jailed opposition leader Alexei Navalny, keeping up the wave of nationwide protests that have rattled the Kremlin. Hundreds have been detained by police. (Photo by Maxim Shemetov/Reuters)

A demonstrator wearing a face mask reading “Who gave the order?” looks on during a protest to mark the International Day for the Elimination of Violence against Women, in Bogota, Colombia on November 25, 2020. (Photo by Luisa Gonzalez/Reuters)

Members of the media document a damaged train carriage extracted from a tunnel after the deadly train derailment north of Hualien, Taiwan on April 6, 2021. (Photo by Ann Wang/Reuters)