When a former Area 51 insider alleges that the Roswell UFO incident was a nefarious Soviet conspiracy masterminded by Stalin, experts investigate if it was indeed an enemy plot against America -- or if the confession is just another cover-up.

A Russian probe discovers the lunar soil was disturbed before the US or USSR got there. Did Nazis arrive first? Have scientists detected a laser signal from a planet capable of supporting life? Is there a Bermuda Triangle of Space?

After NASA's New Horizons spacecraft flies by Pluto, it encounters a strange alien world that shuts down the probe's computers, and experts investigate if this mysterious object is an alien spacecraft hiding at the edge of our solar system.

When NASA discovers something strange on Saturn's biggest moon, experts investigate if aliens feeding on the electric atmosphere could be the culprit. The disturbing evidence points to a grisly apocalypse if these monsters ever make it to Earth.

After Neil Armstrong's moonwalk, he led an expedition to the Amazon to find a legendary library that holds all knowledge of an advanced alien civilization. Experts ask if a close encounter on the moon's surface inspired Armstrong's mysterious quest.

A UFO crashes in Pennsylvania. Was it a secret Soviet satellite or something far more dangerous? On Mercury, NASA finds the impossible: frozen water. A strange object causes a skyscraper-sized shadow on the surface of Mars's largest moon. What is it?

Are burning lights above Nevada and Utah signs of a secret space weapons project? What are the odd trails on the lunar surface near the Apollo landing sites? Does a strange space object spell disaster for the Space Shuttle crew?

Could NASA be responsible for a nuclear explosion on Jupiter? Could new evidence finally solve the mystery of the iconic face on Mars? What unknown force crashed a spacecraft from the Apollo program into the lunar surface?

A strange discovery by NASA's Mars Curiosity rover suggests the Red Planet was home to an alien nuclear war 300 million years ago. Experts investigate if an extraterrestrial Armageddon transformed an earth-like world into the wasteland we know today.

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.

A declassified letter written by President Kennedy demands the CIA share its UFO data with NASA. A bizarre pattern on the surface of Mars could be a coded alien message. Investigators are shocked to find a rocket crash-landed in a crater on the Moon.

The last humans to walk on the Moon discover something strange on the surface. A NASA scientist investigates a strange phenomenon responsible for horrific mass deaths. A landmark NASA mission threatens to destroy the reputation of an American hero.

Three cosmonauts die mysteriously as they re-enter Earth's atmosphere. A declassified document reveals a CIA plan to use a space disaster as a cover to start war and a NASA rover discovers clues that help solve a murder.

Lost tapes reveal that Apollo astronauts heard unexplained transmissions on the far side of the moon, an amateur astronomer spots a strange disturbance in Martian atmosphere & an unidentified object in Earth orbit starts stalking Russian spacecraft.

British astronomers working for the CIA intercept Soviet photos of the moon. A malfunction on the ISS could poison its crew with ammonia gas. A startling image taken by a NASA probe points to evidence that life could exist on Mars.

Two cosmonauts fight for their lives while trapped inside a capsule in a frozen lake. A NASA scientist investigates the deadly Nazi secret that doomed the Hindenburg. NASA astronomers are spooked when the full moon starts affecting their experiments.

A discovery suggests the hellish clouds of Venus may be the origin of life on Earth. A bizarre sighting 2,000 years ago raises the possibility that Earth once had two moons. A scientist helps the FBI crack the 1996 Olympic bombing.

The Viking Lander may have found life on Mars, so why don’t we know about it? What is the most destructive force in the universe? How could a starship be seen in the Aurora Borealis? And what are NASA’s mysterious Moon Pigeons?

Strange flying objects have been caught on NASA’s cameras and astronauts have reported seeing UFOs. Some can be identified; others remain a mystery. We’ll reveal NASA footage and interview the astronauts and scientists.

A chunk of the sun appears to have vanished. An ominous dark craft beneath the Space Shuttle Endeavour. Hubble spots thousands of unidentified objects traveling faster than light. Are we being watched?

What could make a NASA astronaut report seeing a flying saucer in the skies above a US Air Force test range? How have the swirling gases of Saturn formed a perfect Hexagon that has hovered above the planet’s pole for 30 years?

A probe carrying a message to aliens malfunctions as it enters deep space. A NASA mission goes disastrously wrong when an imposter breaches Mission Control. Astronomers may have found an invisible planet around a distant star.

An astronomer records an unusual signal from a distant star. FBI agents find classified documents at the home of a NASA scientist. When scientists discover strange DNA in the octopus, they examine if their origins could be alien.

Astronomers detect a potentially habitable planet tantalizingly close to Earth. A chance discovery at NASA reveals a top secret military space program. The Apollo missions bring back evidence that the moon may be rich in the building blocks for life.

Astronaut Leroy Chao’s spacewalk is interrupted by bright lights flying past. A flying saucer photographed from the Apollo capsule, dark shapes caught on camera shadowing the shuttle. The ideas are science fiction, but the incidents are science fact.

When a Chinese moon rover breaks down, a NASA scientist points to a mysterious material that seemed to sabotage the Apollo missions, decades earlier. The Rosetta spacecraft finds a comet that appears to be singing.

Jupiter is far hotter than it should be, and scientists don't understand why. The Curiosity Rover finds something strange on Mars. Could it be a lost spacecraft or something far more sinister? Detectives turn to NASA for help with a murder cold case.

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.