Throughout human history, there have been sudden and dramatic leaps in our evolution that simply cannot be explained by Darwinian theory. Ancient Astronaut theorists propose that the “missing link” is extraterrestrial intervention. The evidence may be found in our proto-human past, the key moments in our development, and the extraordinary changes witnessed in new generations being born. Could humanity be overdue for the next upgrade? And if so, what might be in store for the human race?

Ancient Astronaut theorists have long proposed that Earth is an extraterrestrial laboratory. If so, does it extend beyond humans into the animal kingdom? Accounts of animalist gods can be found across the globe, including insectoid and reptilian deities that curiously mirror modern alien encounters. Might this point to a direct extraterrestrial tie to the strange creatures on our planet, from Bigfoot and Mothman--to the evolutionary oddities that defy natural development on Earth.

Across nearly every continent on Earth we can find similar remarkable stone structures of unexplainable engineering feats. Might the building of these megalithic sites have been directed by an extraterrestrial hand, as Ancient Astronaut theorists have long proposed? From the curious discoveries made at the Great Pyramid, at Teotihuacan and Stone Henge, new evidence may suggest that these structures are not only connected, but also part of a more profound--and powerful--network.

Humans are just scratching the surface when it comes to what we know about our ancestors from the distant past. Lost cities, ancient texts, mysterious carvings, and unexplained structures provide clues to a long-forgotten time that goes further back in history than we could have ever imagined. From Egypt to China and even Antarctica, Ancient Astronaut theorists propose that the deeper we dig, the closer we will come to proving an extraterrestrial influence on Earth's ancient inhabitants.

Thousands of UFO sightings are reported in the United States every year, and intriguingly many of them center around U.S. military operations. Might extraterrestrials have a special interest in the country's warfare capabilities? Recently, the United States government has officially acknowledged that it is investigating unidentified aerial phenomena. What secrets have been kept from the public--and even some U.S. Presidents? And what role does the public play in demanding answers to our questions about extraterrestrials?

With our latest technological advancements, humanity has entered a new era in the search for life outside of our planet. From the discovery of exoplanets and the exploration of the moon to plans for missions to Mars, could man's quest to understand the universe be built into our DNA? Across the globe, many cultures believe that their ancestors came from the stars. Orion, Sirius and Pleiades are all connected to origins stories for ancient cultures around the world. As scientists continue to explore outer space, are we on the verge of discovering not only alien life but the very extraterrestrials that came to Earth centuries ago?

From the furthest reaches of human history, our ancestors left curious carvings, geo-glyphs, and hieroglyphic messages for future generations to decipher. Is it possible that these mysterious inscriptions, enigmatic crop formations, and encoded sacred architecture signify communication with extraterrestrial visitors? And if so, just what are they trying to tell us?

Throughout the world, there are areas where strange activity, UFOs, bizarre orbs of light, and electromagnetic anomalies are regularly witnessed. Many of these sites correspond to locations where ancient civilizations chose to build and rebuild their most sacred architecture. Ancient Astronaut theorists propose these sites are remnants of a lost extraterrestrial electrical system--one erected to draw energy from the Earth, to fuel spaceships, and possibly even to open gateways into other worlds.

In nearly every generation, there are great minds that can predict the future, seers who possess extrasensory abilities, and visionaries that almost single-handedly push humanity forward into a new age. These great thinkers, including Nikola Tesla, Srinivasa Ramanujan, Steve Jobs and others, have credited their genius to outside inspiration. Could there be an otherworldly source of knowledge that they are tapping into--one that may be steering the course of human history?

Tens of thousands of individuals go missing every year and many are never found. But this is not a new phenomenon. Throughout history, ships and planes have mysteriously vanished mid-journey--and entire civilizations, communities, and tribes have seemingly disappeared from the face of the Earth without a trace. Might there be a connection between all these missing person cases--one possibly involving otherworldly portals and even extraterrestrial beings?

Since the start of the Space Race, humanity has been driven to leave Earth and explore the cosmos. Could there be more to the mission than the public is told? There have been long-standing rumors about the true source for the extraordinary technology that launched us to the moon, curious statements made by returning astronauts, and even impossible architecture allegedly found on the Moon and Mars. Might our space program already have evidence that intelligent life exists in the universe--and that we are not alone?

Across the globe, there are remarkable ruins, statues and carvings that appear to connect diverse ancient civilizations to one another. Hindu idols have been found in South America. Druid structures have been uncovered in the United States. And Egyptian hieroglyphs are carved in rock walls in Australia. Was our world once more interconnected than we ever thought? And if so, do the shared legends of sky gods and visitors from space point to a planet-wide -- extraterrestrial connection?

Throughout history, there have been stories of flying serpents and fire-breathing dragons that descended from the sky, cross-cultural tales of the star ancestors that jumpstarted civilization on Earth, and even ancient lore describing otherworldly beings that interacted with humans in the remote past. Many of these accounts curiously mirror reports of modern-day alien encounters. Could the legends of these strange visitors from the stars be more than mere mythology? And if so, are they the same extraterrestrial beings that are visiting us today?

Military and commercial pilots have been stepping forward in recent years with astounding photos and videos evidence of Unidentified Aerial Phenomena. Intriguingly, these contemporary sightings share an eerie resemblance to unexplainable objects chronicled in historical records.

Government whistleblowers have been instrumental in bringing attention to the often-dismissed topic of unidentified aerial phenomena. From Bob Lazar's controversial claims about reverse-engineering a UFO craft at Area 51, to shocking UAP video evidence released by former pentagon employee Luis Elizondo, and even to the recent congressional testimony on classified government UFO programs and alleged possession of extraterrestrial entities, for decades informants have risked their reputations and even their safety to publicly reveal their knowledge of an extraterrestrial cover-up. Might these disclosures - and others - finally force the government to make public their top-secret information on alien activity here on Earth?

Meteor impacts, cosmic microbes, and space viruses have significantly impacted life as we know it. Recent discoveries suggest that some of the debris falling to Earth could have originated from other star systems and may even be of artificial origin. If so, might this point to ongoing extraterrestrial involvement with our planet, as Ancient Astronaut theorists suggest?

From rumors of covert extraterrestrial dealings with world leaders to the extraordinary claims of alien abductees and harrowing tales of pilot encounters with UFOs, a growing body of evidence suggests otherworldly beings have been making contact. What if this isn't a new occurrence? Ancient Astronaut theorists suggest that these extraterrestrial close encounters have been taking place for hundreds, if not thousands, of years.

Archaeologists have uncovered temple complexes dating far back into human prehistory. They've identified ancient constructions submerged deep in our oceans, and even discovered that many of today's sacred sites were constructed atop older ruins.

The largely unexplored continent of Antarctica has long been subject to rumors of UFOs, underground tunnel networks and concealed ancient structures, giving rise to speculation about an alien presence beneath its icy surface.

A look at the potential for extraterrestrial connections to Earth's mountain ranges, which are often considered mystical places; a look at Mount Kailash in the Himalayas, Mount Musine in Italy and Mount Shasta in Northern California.

A look at details of heavenly flying chariots, abductions from Earth, and otherworldly visitors in books stricken from the Hebrew Bible; accounts of advanced technology, flying machines, and powerful weaponry in the sacred Vedic texts of India.

Prominent world leaders including the British Royal Family, Japan's Defense Minister, the Chinese government and Russia's former president have allegedly investigated Unidentified Aerial Phenomena (UAPs) for years.

Across the globe, monumental stone figures silently bear witness to a forgotten era; on Easter Island, there are hundreds of Moai figures carved from volcanic rock, each weighing up to 90 tons, with the tallest standing over 30 feet.

Investigators discover compelling evidence of concealed pyramids in Alaska, China and Bosnia; the Great Pyramid of Giza in Egypt continues to unveil secrets with the discovery of a hidden chamber, raising new questions about its purpose and design.

Examining whether shadow people, spirits, poltergeists and other strange beings that have appeared in ancient texts and folklore could be otherworldly visitors that originate from unseen realms and coexist within humans' reality.