Science HDTV (SCIHD)

Experts take a close look at the Tower of London, a centuries-old engineering marvel shrouded in a mysterious and grisly past. (Repeat).

Experts explore the ruins of the world's oldest sunken city, using hi-tech underwater archaeology. (Repeat).

Deep in the Iraqi desert, the ziggurat towers over the remains of the first civilization ever known in human history. Armed with pioneering satellite imagery, experts investigate the dark mysteries behind this massive, ancient structure. (Repeat).

Only one Egyptian pyramid was ever constructed to look like it floats on water. Using pioneering drone-scanning technology, experts decode the ancient secrets of the pharaoh that are locked inside its hidden tunnels. (Repeat).

Experts uncover the true story behind the worst nuclear disaster in history. (Repeat).

Archaeologists reveal the mystery behind the decapitated statues of Mount Nemrut. (Repeat).

Experts uncover the true story behind the worst nuclear disaster in history. (Repeat).

Archaeologists reveal the mystery behind the decapitated statues of Mount Nemrut. (Repeat).

Only one Egyptian pyramid was ever constructed to look like it floats on water. Using pioneering drone-scanning technology, experts decode the ancient secrets of the pharaoh that are locked inside its hidden tunnels. (Repeat).

Experts use new technology to investigate the origins of Stonehenge. (Repeat).

Experts take a close look at the Tower of London, a centuries-old engineering marvel shrouded in a mysterious and grisly past. (Repeat).

British astronomers intercept Soviet photos of the moon; an ISS malfunction could poison the crew with ammonia gas; and a picture by a NASA probe indicates that life could exist on Mars. (Repeat).

When the Soviet Union unveils its own space shuttle, the CIA hatches a secret revenge plot. Recent discoveries shed new light on the destruction of Sodom and Gomorrah. A missing nuclear weapon could threaten a NASA base in the Arctic. (Repeat).

Life on Mars; the universe's most destructive force; a starship found in the aurora borealis; and strange moon pigeons. (Repeat).

New discoveries have revealed thousands of exoplanets beyond our solar system, and some resemble earth enough that one could be a new home for humanity. But even with cutting-edge technology, finding the perfect one is the scientific challenge of the age. (Repeat).

Planets that orbit two suns instead of one might be deadly hell worlds, but new discoveries reveal that sci-fi star systems with binary stars might be optimal places for alien life. (Repeat).

Peter and Elroy join in an archaeological dig on Runestone Hill. (Repeat).

The archaeologists investigate charred wood remains at the original discovery site. Peter and Elroy compare Olof Ohman's hand-copied rune text to the text on the runestone. Peter and Elroy ask Scott to perform geologic tests on a whetstone found deeper in the ground beneath the runestone. (Repeat).

Peter, Elroy, and Sturla visit the coast and islands of Maine to view possible Viking trading sites. (Repeat).

Peter Stormare and Elroy Balgaard investigate a set of runestone relics that could reveal new truths about the mysterious Kensington Runestone. (Repeat).

Hollywood actor Peter Stormare and Elroy Balgaard investigate a theory that the Knights Templar were in America; new discoveries lead them deeper into a web of secret symbols and intrigue. (Repeat).

Peter Stormare and Elroy Balgaard venture to a set of islands that could have been the site of Viking landings in America. (Repeat).

Josh investigates how a group of Norse tribesman gained power in medieval Europe. His search for answers begins in their one-time home base of Denmark and continues on to the first place they expanded off the continent, the remote island of Iceland. (Repeat).

Josh traces the Vikings' westward expansion from the volcanic landscape of Iceland to a settlement in Greenland and into North America. He aims to find out if the Norse explorers landed in the United States. (Repeat).

In England, Josh unearths a cache of ancient treasure as he chases the legend of Queen Boudica, the legendary Celtic queen who nearly defeated the invading Roman army 2,000 years ago. (Repeat).

Part 1 of 2. Josh journeys through the land of the Nile to uncover the secrets of the most powerful, and most elusive, women in ancient Egypt: Hatshepsut, Nefertiti and Cleopatra. (Repeat).

Part 2 of 2. Josh continues his journey through Egypt to uncover the secrets, and possibly the final resting place, of ancient history's most powerful women rulers: Nefertiti and Cleopatra. (Repeat).

Josh Gates ventures into the flooded pyramid tomb of a Kush king. Scaling mountains to unravel the secrets of the Kingdom of Kush's conquest of Egypt, he dives into murky waters in search of the mummified remains of the king. (New).

Josh travels to the Holy Land to find a lost city where Jesus performed many miracles and is also home to three apostles. While investigating competing sites that claim to be the lost city, Josh reveals an inscription that hasn't been seen in 1,400 years. (New).

Part 2 of 2. Josh continues his journey through Egypt to uncover the secrets, and possibly the final resting place, of ancient history's most powerful women rulers: Nefertiti and Cleopatra. (Repeat).

Josh Gates ventures into the flooded pyramid tomb of a Kush king. Scaling mountains to unravel the secrets of the Kingdom of Kush's conquest of Egypt, he dives into murky waters in search of the mummified remains of the king. (Repeat).

Josh travels to the Holy Land to find a lost city where Jesus performed many miracles and is also home to three apostles. While investigating competing sites that claim to be the lost city, Josh reveals an inscription that hasn't been seen in 1,400 years. (Repeat).

Part 1 of 2. Josh journeys through the land of the Nile to uncover the secrets of the most powerful, and most elusive, women in ancient Egypt: Hatshepsut, Nefertiti and Cleopatra. (Repeat).

Peter Stormare and Elroy Balgaard venture to a set of islands that could have been the site of Viking landings in America. (Repeat).

Josh investigates how a group of Norse tribesman gained power in medieval Europe. His search for answers begins in their one-time home base of Denmark and continues on to the first place they expanded off the continent, the remote island of Iceland. (Repeat).

A declassified letter written by President Kennedy demands that the CIA share its UFO data with NASA; a pattern on the surface of Mars could be a coded alien message; and investigators are shocked to find a rocket crash-landed in a crater on the moon. (Repeat).

When NASA spots a something on Mars that resembles Stonehenge, they investigate what could have made this strange structure. Scientists discover a mysterious hole in Saturn's rings. An ancient tribe claims contact with alien visitors. (Repeat).

A dark spot on the sun; an unusual spacecraft; UFOs. (Repeat).

A look at NASA's Cassini spacecraft, which revealed certain secrets of Saturn until it vaporized in its atmosphere. However, its legacy lives on, as fresh data from the probe helps scientists make brand-new discoveries. (Repeat).

Our solar system is home to hundreds of strange, tiny worlds called dwarf planets, and new discoveries reveal the secrets of these mysterious places. (Repeat).

There is a hellish planet in our solar system, covered in thick dense clouds and roasted by colossal temperatures. Incredibly this is a vision of Earth's future. It's Earth's twin, Venus. (Repeat).

A mysterious 2000-year-old jar containing copper and iron may be the most controversial archaeological find of all time; using the best available data, experts reconstruct this priceless artifact to determine if it could actually be world's first battery (Repeat).

An ancient piece of corroded metal is more than it seems: an alien-looking device of intricate dials and cogs. Using cutting-edge imaging technology, experts examine what could actually be a 2000-year-old computer. (Repeat).

A bizarre 3,000-year-old gold relic is believed to form a highly complex celestial code; using advanced imaging technology, experts speculate that it could be an ancient device for predicting the future. (Repeat).

Cameras capture what appears to be a three-foot-tall humanoid in the jungles of Indonesia, but some speculate it's evidence of a long-lost species that vanished thousands of years ago. (Repeat).

A villager films a river bank suddenly rising as though a gigantic creature is emerging from beneath the waters in India; experts investigate a potential network of criminal gangs who may be stripping river beds of a very valuable commodity. (Repeat).

Cameras onboard a cargo vessel captured eerie images of the huge ship getting torn in half. What is even more unsettling is that it looks like it's been ripped by an invisible and mysterious force. Experts also investigate a dangerous part of the sea that is akin to the Bermuda triangle mystery. (Repeat).

A team of experts analyzes surveillance footage to uncover the science behind bizarre occurrences caught on camera. (Repeat).

A gravity-defying cube spins through the skies over Missouri, raising questions about what propulsion system could power the mysterious aircraft. Experts investigate footage released by the Pentagon that confirms the existence of these ominous objects. (Repeat).