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)

Coloured X-ray of a barn owl. A physicist has used X-ray to create an extraordinary collection of artwork. Arie van't Riets pictures reveal birds, fish, monkeys and flowers in an incredible new light. The 66-year-old, from Bathmen in the Netherlands, began X-raying flowers as a means to teach radiographers and physicians how the machine worked. But after adding a bit of colour to the pictures, the retired medical physicist realised the potential for an exciting new collection of art. (Photo by Arie van't Riet/Barcroft Media)

People walk down a makeshift modeling runway as they take a break from marching during the Brooklyn Liberation's Protect Trans Youth event on June 13, 2021 in the Brooklyn borough in New York City. Brooklyn Liberation organized a march and rally as an emergency action response to legislation to restrict trans rights across 34 states. According to the Human Rights Campaign, there have been over 250 bills introduced in state legislatures aimed at the LGBTQ community in 2021. (Photo by Michael M. Santiago/Getty Images)

A model prepares backstage during the body painting show : Miracle World The Ocean organized by Unipa Surabaya at Grand Atrium Royal Plaza on June 21, 2021 in Surabaya, Indonesia. (Photo by Robertus Pudyanto/Getty Images)

Soldiers patrol in Petion Ville, the neighborhood where the late Haitian President Jovenel Moise lived in Port-au-Prince, Haiti, Wednesday, July 7, 2021. Moïse was assassinated in an attack on his private residence early Wednesday, and first lady Martine Moïse was shot in the overnight attack and hospitalized, according to a statement from the country’s interim prime minister. (Photo by Joseph Odelyn/AP Photo)

Belgium's Crown Princess Elisabeth, center, marches past the Royal tribune with cadets of the military school during the National Day parade in Brussels, Wednesday, July 21, 2021. Belgium celebrates its National Day on Wednesday in a scaled down version due to coronavirus, COVID-19 measures. (Photo by Olivier Matthys/AP Photo)

Hikers, left, Sarah Done 24 and Catherine Edwards enjoy a climb up Box Hill during Storm Evert in Surrey in South East England on July 30, 2021. Storm Evert is the UK's fourth named storm since October 2020. (Photo by London News Pictures)

A protester wearing improvised protective headgear walks away from a cloud of tear gas on July 18, 2021 in Bangkok, Thailand. Student protesters called for a demonstration demanding the resignation of Thailand Prime Minister Prayuth Chan-o-Cha, despite a ban on gatherings because of the country's current Covid-19 outbreak, and folded a demand for better action in combating the virus into their demands. (Photo by Sirachai Arunrugstichai/Getty Images)