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)

“The McDonnell Douglas KC-10 Extender is an air-to-air tanker aircraft in service with the United States Air Force derived from the civilian DC-10-30 airliner. The KC-10 was the second consecutive McDonnell Douglas transport aircraft to be selected by the US Air Force following the C-9 Nightingale. The similar KDC-10 is in service with the Royal Netherlands Air Force.”

Photo: A B-52G Stratofortress aircraft takes off with another B-52G close behind. Three cells of six B-52 and KC-10 Extender aircraft will takeoff seconds apart under combat conditions during the minimum interval takeoff exercise. The exercise is a part of an operational readiness inspection by the Strategic Air Command Inspector General Team. (Photo by USAF). 1998

“The Naval and Military Club is a gentlemen's club in London, England. It was founded in 1862 because the three then existing military clubs in London – the United Service, the Junior United Service and the Army and Navy – were all full. The membership was long restricted to military officers. This is no longer the case, but it still has a predominantly military and ex-military membership”. – Wikipedia

Photo: Members of the prestigious “In and Out Club”, one of the oldest and most exclusive clubs in London, march around St. James's Square during the club's 150th birthday celebration on March 1, 2012 in London, England. Patrons of the private members club, whose official title is the Naval and Military Club, gathered in St. James's Square in Central London before marching with the Band of the Royal Logistics Corps to be greeted by HRH The Duke of Edinburgh, and retiring for lunch inside the club. (Photo by Dan Kitwood/Getty Images)

From Tibetan monks playing basket ball with ice thawing high up in the Himalayas, to the pollution that hides behind the Taj Mahal, here’s pick from 60 exceptional environmental photographs, by photographers and filmmakers from 70 countries, that will go on show at the Royal Geographical Society in London from 29 June to 21 August. The winners will be announced on 28 June. Here: Gravel Workmen of Chittagong, Bangladesh, by Faisal Azim. Gravel workmen look through a glass window at a gravel-crushing yard in Chittagong. Full of dust and sand, it is an extremely unhealthy environment for working, but still hundreds of people work here for their livelihoods. (Photo by Faisal Azim/2016 Atkins CIWEM Environmental Photographer of the Year)

During a jungle survival program February 20, 2013 taught by Royal Thai Special Forces in Sannapit, Thailand, U.S. Marines learned to catch cobras and drink their fresh blood, not to mention eat forest insects and pull the heads off of chicken. The training was part of Operation Cobra Gold 13, the 32nd edition of international military exercises hosted by the Thai. According to a U.S. Marines press release, Cobra Gold is the largest exercise of its kind in Asia and incorporates troops from five other nations in addition to the U.S. and Thailand. The Daily Mail reports that the Marines were invited to experience the local custom of drinking cobra blood after being taught to catch and kill cobras in the wild. As CNN notes, Cobra blood is believed to be a panacea and aphrodiasic in parts of Southeast Asia. In Jakarta, vendors can earn over $100 a night selling shots of cobra blood mixed with liquor. (Photo by Pornchai Kittiwongsakul/AFP Photo)

Hugh Hefner spanks playboy models Izabella Kasprzyk and Bridget Marquardt during their birthday dinner party at Joya restaurant on September 25, 2002 in Beverly Hills, California. Playboy founder and sеxual revolution symbol Hugh Hefner has died at age 91. The magazine released a statement saying Hefner died at his home in Los Angeles of natural causes on Wednesday night, September 27, 2017, surrounded by family. (Photo by David Klein/Getty Images)

For the Torajan people of Indonesia, death is part of a spiritual journey: families keep the mummified remains of their deceased relatives in their homes for years – and traditionally invite them to join for lunch on a daily basis – before they are eventually buried. Here: Todeng died in 2009. A young relative of his, Sam, lights him a cigarette and changes his glasses. (Photo by Claudio Sieber Photography/The Guardian)

A priest comforts one of the relatives of the victims, before a mass in their memory, as Lebanon marks one-year anniversary of Beirut port explosion, at the port in Beirut, Lebanon on August 4, 2021. United in grief and anger, families of the victims and other Lebanese came out into the streets of Beirut on Wednesday to demand accountability as banks, businesses and government offices shuttered to mark one year since the horrific explosion. (Photo by Aziz Taher/Reuters)