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)

Rescuers attend an injured fan lying on the field of the Cuscatlan stadium in San Salvador, El Salvador, Saturday, May 20, 2023. At least nine people were killed and dozens more injured when stampeding fans pushed through one of the access gates at a quarterfinal Salvadoran league soccer match between Alianza and FAS. (Photo by Milton Flores/AP Photo)

This undated photo shows the Arctic National Wildlife Refuge in Alaska. (Photo by U.S. Fish and Wildlife Service/Getty Images)

Travellers wait in queue to test for COVID-19 at a train station in Mumbai, India, Tuesday, November 30, 2021. (Photo by Rafiq Maqbool/AP Photo)

A woman takes photos as Mount Agung volcano sends up another plume of smoke, seen from the Kubu subdistrict in Karangasem Regency on Indonesia's resort island of Bali on July 5, 2018. Mount Agung roared to life again on July 2, belching a plume of ash 2,000 metres (6,500 feet) high, as well as temporarily shuttering the airport and grounding hundreds of flights after erupting the week before. (Photo by Sonny Tumbelaka/AFP Photo)

This undated photo provided by NOAA in May 2018 shows aurora australis near the South Pole Atmospheric Research Observatory in Antarctica. When a hole in the ozone formed over Antarctica, countries around the world in 1987 agreed to phase out several types of ozone-depleting chemicals called chlorofluorocarbons (CFCs). Production was banned, emissions fell and the hole shriveled. But according to a study released on Wednesday, May 16, 2018, scientists say since 2013, there’s more of a banned CFC going into the atmosphere. (Photo by Patrick Cullis/NOAA via AP Photo)

Staff members clean the court during the Women's Preliminary Round - Pool B volleyball match between China and Argentina on day ten of the Tokyo 2020 Olympic Games at Ariake Arena on August 2, 2021 in Tokyo, Japan. (Photo by Carlos Garcia Rawlins/Reuters)

A general view shows a column of steam emerging from Popocatepetl volcano, after an increase in volcanic activity with steam and ash eruptions have been registered recently, according to local media, as seen from San Andres Cholula municipality, in the state of Puebla, Mexico on February 1, 2023. (Photo by Henry Romero/Reuters)