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)

This picture taken on April 25, 2022 and released from North Korea's official Korean Central News Agency (KCNA) on April 26 shows a military parade to celebrate the 90th anniversary of the founding of the Korean People's Revolutionary Army at Kim Il Sung Square in Pyongyang. (Photo by KCNA via KNS/AFP Photo)

People walk behind the Medusa head in the Basilica Cistern in Istanbul, Turkey, 24 July 2022. The site has been restored by the Istanbul Metropolitan Municipality and is now open for visitors again. The Byzantine structure was commissioned by Emperor Justinian and built in 532. The underground Basilica, also called Underground Cistern, is the largest well preserved cistern in Istanbul, which rests on a total of 336 columns. According to historical texts, more than 7,000 slaves were involved in the construction of the cistern. (Photo by Sedat Suna/EPA/EFE)

Palestinian demonstrators take cover during clashes with Israeli soldiers following a protest against the expropriation of Palestinian land by Israel in the village of Kfar Qaddum in the occupied West Bank, near the Jewish settlement of Kedumim, on December 9 2022. (Photo by Zain Jaafar/AFP Photo)

A reveller smeared in vermilion powder celebrates the Bisket Jatra Festival in Thimi in the Bhaktapur District on the outskirts of Kathmandu on April 15, 2023. (Photo by Prakash Mathema/AFP Photo)

A firefighter works outside of a building where an explosion and a fire broke out in Shimbashi area of Tokyo on July 3, 2023. (Photo by Yuichi Yamazaki/AFP Photo)

A guard follows participants down a hallway in “Squid Game: The Trials”, an in-person interactive competition experience based on the Netflix show “Squid Games”, on December 20, 2023 in Los Angeles, California. At “Squid Game: The Trials” in Los Angeles, fans of all ages can relive the most emotional moments of Netflix's South Korean hit show – but there is a lot less blood and no one wins any prize money. (Photo by Robyn Beck/AFP Photo)

Protesters throw fireworks at riot police during clashes in Nanterre, near Paris, France, 29 June 2023. Violence broke out after police fatally shot a 17-year-old during a traffic stop in Nanterre on 27 June 2023. According to the French interior minister, 31 people were arrested with 2,000 officers being deployed to prevent further violence. (Photo by Yoan Valat/EPA/EFE/Rex Features/Shutterstock)