The Tunguska event was an explosion that occurred on 30 June 1908, in the Siberian region of Russia, possibly caused by a meteor air burst. The event has inspired much speculation and appears in various fictional works. Literature In Larry Niven's 1975 novelette The Borderland of Sol, the Tunguska event is proposed to have been caused by the passage through the Earth of a microscopic quantum black hole with the mass of a small asteroid, which then headed back into space and traveled to the outskirts of the Solar System, where it was located 800 years later. Soviet engineer and science fiction writer Alexander Kazantsev in his novel Burning Island mentions the event as the crash site of an alien spaceship, resulting in the discovery of radium-delta, the supposed fuel of the ship. His short story "A Visitor From Outer Space", written in 1946, describes the crash site and eyewitness accounts in detail. In this story a nuclear-powered Martian spaceship, seeking fresh water from Lake Baikal, blows up in mid-air. His story "The Explosion" includes the theory that the Tunguska event was the result of the activities of extraterrestrial beings, including an exploding alien spaceship or an alien weapon fired to "save the Earth from an imminent threat". Many events in Kazantsev's tale, which was intended as pure fantasy, were subsequently confused with the actual occurrences at Tunguska. Cartoons and comics Prog 81 of 2000 AD had a Tharg's Future Shock short story where a ship went back in time to view the Tunguska event. When it arrived in 1908, the ship went out of control, entered the atmosphere and became the cause of the event. TV and film Siberia is an American supernatural drama television series shot in the style of a reality television show where 16 contestants must survive in the Siberian territory of Tunguska, about 100 years after the Tunguska event. Shortly after arrival, the contestants notice strange things and are abandoned by the production of the reality show. The television series The Secret KGB UFO Files (Phenomenon: The Lost Archives) in 1998, broadcast on Turner Network Television, referred to the Tunguska event as "the Russian Roswell" and claimed that crashed UFO debris had been recovered from the site. In the Doctor Who episode "In the Forest of the Night", the Doctor mentions the Tunguska event as an example of where rapid tree growth helped save humanity.