In the 21st century, mainstream scholars, scientists, and world governments have for the first time openly joined the hunt for intelligent life beyond Earth. But while such an effort has never been made public before, in reality, the search for proof of extraterrestrial life has been underway for decades. Starting around 1947, a series of unexplained sightings and mysterious events forced certain high-level members within the US government to officially become alien hunters. Projects Sign, Grudge, and Bluebook were government programs to research UFO sightings--and by some accounts, literally hundreds of the reported events were unable to be explained. Ancient Astronaut theorists suggest there is evidence that similar endeavors were even made thousands of years ago, sighting ancient astronomical observatories found all over the world, and new evidence that Babylonians were tracking the movements of the planets over 2,000 years ago.