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)

Participants dressed as Santa Claus take part in the Great Edinburgh Santa Run on December 11, 2011 in Edinburgh, Scotland. Around a thousand people took part in the annual fundraising event, with all money raised being donated to the charity “When You Wish Upon a Star”. (Photo by Jeff J. Mitchell/Getty Images)

Ryo Minemizu, one of Japan’s emerging stars in the field of marine life photography and the 2017 winner of the Nikkei National Geographic photography prize, captures the beauty and complexity of plankton that drift in our planet’s oceans and other bodies of water in meticulous detail. Here: Batesian mimicry by a Soleichthys fish larva. (Photo by Ryo Minemizu/The Guardian)

“Camille Lepage, a 26-year-old French photojournalist who had spent months documenting deadly conflict in Central African Republic has been killed, the French presidency said Tuesday, May 13. Lepage, a freelance photographer whose work was published in major French and American newspapers, died in western Central African Republic not far from the border with Cameroon, authorities said”. – Associated Press. Photo: Anti-balaka fighters from the town of Bossembele patrol in the Boeing district of Bangui, Central African Republic, February 24, 2014. (Photo by Camille Lepage/Reuters)

Projectionist Antonio Feliciano, 75, checks his projector before showing a film in Monforte, Portugal May 16, 2015. Shades of Oscar-winning classic "Cinema Paradiso" run through the life of Feliciano, a sprightly 75-year-old who fears he may be the last of Portugal's travelling film projectionists.After six decades travelling four million km (2.5 million miles) to screen 4,000 films in Portugal's far-flung villages, Feliciano does not plan to retire just yet. But he is resigned to the fact that the Internet, digital TV and distribution monopolies have made his craft obsolete. (Photo by Rafael Marchante/Reuters)

An activist kicks the shields of the military police officers during a demonstration in the military zone of the 27th infantry battalion in Iguala, Guerrero, January 12, 2015. Activists and relatives of the 43 missing trainee teachers from Ayotzinapa's teacher training college broke into the military zone, located less than a mile from where the students went missing, in an attempt to look for the missing students.The remains of only one of the 43 students has been identified so far. (Photo by Jorge Dan Lopez/Reuters)