For as long as humanity has been able to gaze up at the cosmos we've been wondering 'Are we alone in the universe or is there any life out there?'
It's a question which has dominated our collective thoughts - and the science fiction genre - for decades, but, if claims from one declassified CIA report are to believed, it would appear that aliens not only exist, but have been living among us for quite some time.
So grab your tinfoil hats and unfurl your 'welcome aliens' banner, as its time to unpack the latest arguments for extraterrestrial life existing.
During the height of the Cold War, agents at the CIA left no stone unturned when it came to investigating methods to one-up the Soviet Union.
This meant exploring some pretty whacky avenues, including research on mind control and fitting cats with listening devices.
One such project which falls under this category is 'Stargate Project', which saw the CIA explore the possibility of 'remote viewing' — an idea which individuals with psychic abilities could gather information about distant objects or people.
Files from the Stargate Project would later be declassified in 2000, which meant the public were able to learn about 'Description of Personnel Associated 'ET' Bases' and the documents are fascinating.
According to one document, a test subject claimed to have experience of remotely visiting three alien bases, two of which were supposedly on Earth.
The test subjected described some of the aliens as appearing more extraterrestrial than others (Getty Stock Images) A description of the two bases lists one as being in Mount Hayes, Alaska, while the other was either in South America or Africa. Meanwhile, the third base was on the Titan, Saturn's largest moon.
"So far have run into three types of entities associated with bases at various locations within the solar system," the document reads.
The test subject then goes on to describe the 'entities' working inside each base, with some of the beings appearing to be more humanoid than others.
On the Titan base, they encountered what appeared to be human scientists, while the two bases on Earth were staffed by beings with more extraterrestrial features, such as one being with 'a very large, rounded-shaped head' and another individual who was almost human but 'lacked definitive facial features'.
The test subject doesn't go into specific detail about what the bases look like, but adds that all beings were working on a variety of tasks, including working at a 'circular console'.
Descriptions for the three bases, two of which were allegedly on Earth (CIA) They also described one of the beings as an 'attractive female' with 'brown shoulder length hair' - because this is obviously the most important details of intelligence gathering.
The project was ultimately scrapped in 1995 after it was concluded that physic powers aren't a useful tool for intelligence gathering, which seems a little obvious in hindsight but hey, times were tough.
But don't feel too disheartened, as researchers recently unveiled an exoplanet which shows the most promise of being hospitable to alien life.
Just don't be expecting to find green men in suits.