The truth behind the U.S. government's secret Pentagon program on UAPs, Unidentified Aerial Phenomena, otherwise known as UFOs, is exposed.

The enterprising alien who wants to visit Earth faces a number of daunting challenges. This program examines the advanced technologies he would need with an emphasis on concepts for interstellar travel humans are exploring.

What if an extra-terrestrial force attacked Earth? What might that look like and how will the people of Earth respond? Consulting a cast of world-renowned scientists, survival experts and defense experts, National Geographic explores this frightening scenario. Experts reveal what could motivate alien invaders to attack Earth, and speculate on how the attack might play out, the strategy alien invad...

A journey through the evolution of time travel; from it origins, it's evolution and influence in science fiction, to the exciting possibilities in the future.

Scientists and sci-fi writers explore a hypothetical first-contact event between aliens and humans.

The search for other life in the Universe begins in our imagination as we travel to undiscovered planets out in deep space.

The truth behind the U.S. government's secret Pentagon program on UAPs, Unidentified Aerial Phenomena, otherwise known as UFOs, is exposed.

Scientists and sci-fi writers explore a hypothetical first-contact event between aliens and humans.

On a late summer evening in 1977, Ohio radio astronomers discovered a strong, interstellar signal that is believed by many to be the best evidence of communication from an extraterrestrial civilization.

A journey through the evolution of time travel; from it origins, it's evolution and influence in science fiction, to the exciting possibilities in the future.