Science Channel HD

The CIA's MK-Ultra program sought to create mind control methods through unethical human experimentation, and now, experts investigate classified documents that reveal the horrific atrocities that were carried out in the pursuit of national security.

The location of King Solomon's Mines has baffled historians for centuries and continues to lure treasure hunters today; archaeologists investigate evidence that may uncover the unlikely truth behind this source of untold riches.

Mary Magdalene played a pivotal role in early Christianity and witnessed the execution and resurrection of Jesus Christ; experts investigate the truth behind her mysterious disappearance and embark on a quest to locate her undiscovered remains.

The ancient site of Gobekli Tepe is the oldest building complex ever discovered and continues to baffle archaeologists today; now, experts investigate new theories behind its enigmatic construction as a possible commemoration to a cataclysmic event.

The magnificent tomb of Alexander the Great mysteriously vanishes and becomes a legend; using CGI, investigators piece together the evidence to reveal where his tomb lies and what it might look like.

A subterranean Neolithic temple discovered on the island of Malta contains the skeletal remains of thousands of humans; experts use forensic archaeology to investigate elongated skulls that may unlock the secrets of an advanced, lost civilization.

Life may have been found on Mars; mysterious Moon Pigeons.

Scientists wonder why Jupiter is hotter than it should be; the Curiosity Rover finds something strange on Mars; detectives turn to NASA for help with a murder cold case.

The discovery of geysers on a moon; NASA's mission to detect life; an object is spotted approaching an asteroid.

Star systems with binary stars, once relegated to science-fiction, may actually exist and serve as ideal places for alien life to thrive.

Uranus and Neptune are mysterious, icy worlds at the edge of the solar system; new discoveries reveal that these strange planets may have helped start life on Earth.

When a U.S. Air Force intercept aircraft chases after a UFO, it vanishes forever without a trace; a new investigation tries to uncover what caused this mysterious disappearance.

When someone picks up a radio distress call from a seven-year-old boy lost alone in the desert, authorities embark on a search-and-rescue mission to find him; as the hunt continues, the case becomes more and more mysterious.

A Russian radio station has broadcast a signal nonstop since the Cold War, and no one knows why; experts use hi-tech methods to investigate what it is and what might happen if it ever stops.

When a powerful radio beam originating from deep space is detected by experts on Earth, some suspect it's hard evidence of extraterrestrial life; new investigations into this shocking signal might reveal the truth.

When two experts build their own radio-listening station to intercept the secret communications of American and Soviet astronauts, they capture traces of a haunting voice that may be a lost Russian cosmonaut.

Experts use cutting-edge technology to investigate a mysterious phenomenon at the tomb of a 3,000-year-old Egyptian pharaoh.

When something strange is caught on camera in a tunnel beneath the Colombian jungle, experts wonder if it's a wormhole to far-off places in the cosmos; using cutting-edge tech, they investigate if there's an interdimensional conspiracy at play.

When footage of a strange deep-sea vessel is uncovered, experts wonder if it's evidence of an autonomous alien craft sent to explore earth, and using cutting-edge tech, investigators follow the clues to an unexpected explanation.

When a ghostly encounter in a cemetery is caught on camera, experts use cutting-edge tech and the latest science to investigate if something paranormal is at play.

When a terrifying tower of fire is caught on camera, eyewitnesses fear an alien invasion; using cutting-edge science, experts investigate the threat causing this nightmarish phenomenon, and if a cover-up is hiding the truth.

When something strange is recorded flying in Mexico, some wonder if it's a witch reputed to kidnap children; others believe it's evidence of a new way to smuggle drugs or a top-secret technology.

On a Native American reservation in Utah, evidence of a man transforming into an animal is caught on camera, and some experts ask if it's proof of a Skinwalker, a legendary evil creature that can shapeshift into a deadly beast.

When a massive plume of smoke suddenly erupts from the ground in Manhattan, experts investigate if this terrifying event is evidence of a volcano that's waking up beneath the streets of New York City -- and if it's almost due to blow.

When something strange is recorded flying in Mexico, some wonder if it's a witch reputed to kidnap children; others believe it's evidence of a new way to smuggle drugs or a top-secret technology.