Sky History 2 HD Today

Experts analyse whether natural causes were responsible for the volcanoes, earthquakes and floods of ancient times - and the possibility that it was down to aliens

Recounting how members of a Christian youth group observed a falling star while on a hillside. Things became even more unusual when an object landed close to them

A hitchhiker spots a pattern of lights and is terrified when they seem to attack him. A sighting in France becomes one of the most investigated cases in UFO history

Alice Roberts and Matt Williams visit the Dorset Country Museum, where they explore finds from archaeological digs across the west of Britain

Andy McGrath heads to the home of palaeontology on Dorset's Jurassic Coast and braves the collapsing cliffs of Lyme Regis to bring back one of its many fossils

An auction in Norwalk becomes challenging when Allen and Ton go up against a cowboy couple. A grappling hook and a 3D printer are some of the lots in the auction

An auction in Whittier sees a buyer named Big Dave try to take it all. The guys win a cool food truck and an off-road rock crawler after some losses

The connection between the development of military devices and the aftermath of their usage - dynamics that shaped several millennia of human fate

The design, service and loss of some of the world's greatest ocean liners. The Normandie was set alight while being converted for wartime use as a troopship

A sinister giant swastika that appeared in a forest in Germany. Plus, mysterious markings spotted in an isolated corner of Antarctica - how did they get there?

Hitler's invasion of the Soviet Union on June 22, 1941. His aim was to weaken Britain in Europe and gain 'lebensraum', or living space, in the East

Treblinka, Majdanek and Sobibor, the camps used in Operation Reinhardt, a murder campaign in which the Nazis murdered almost two million people over two months in 1942 and 1943

Experts investigate the work of Nasa and secret government files relating to extraterrestrial activity, looking for proof of alien contact in the recent or distant past

Experts explore the similarities between huge pyramids across the world, and hypothesise on whether extraterrestrials could have influenced their construction and design

Farmer Edwin Fuhr recalls harvesting crops when he saw a metal object hovering in his field. Almost immediately, four identical objects appeared

Strange light patterns are seen in the Texas sky. In France, a man's knee injury is suddenly healed after an odd encounter

Items from archaeological digs from the north of Britain, including examples from the Heart of Neolithic Orkney World Heritage Site, Cumbria and the Highlands

Andy McGrath heads to Scotland, learning about a terrifying family of cannibals who used to prey upon weary travellers, and the prehistoric origins of the Loch Ness monster

The design, service and loss of some of the world's greatest ocean liners. The Normandie was set alight while being converted for wartime use as a troopship

Visits to the most remote, cold and inhospitable places on the planet to reveal great mysteries that have been frozen in time

Giorgio Tsoukalos takes a look back at the most compelling investigations of all, and events that he believes represent real encounters with extraterrestrial visitors

Hitler's invasion of the Soviet Union on June 22, 1941. His aim was to weaken Britain in Europe and gain 'lebensraum', or living space, in the East

Treblinka, Majdanek and Sobibor, the camps used in Operation Reinhardt, a murder campaign in which the Nazis murdered almost two million people over two months in 1942 and 1943

Egyptian queen Cleopatra's reputation as a ruthless genius. She would do anything necessary to cling to power in the face of an ever-expanding Roman Empire

Experts explore the similarities between huge pyramids across the world, and hypothesise on whether extraterrestrials could have influenced their construction and design