posted on Dec, 28 2012 @ 10:59 PM
"Proof" is a big word. To prove the existence of intelligent extraterrestrials to my satisfaction would require multiple high-quality witnesses to
multiple incidents of face-to-face contacts with such beings accompanied by high-quality recordings of multiple types of sensor data (e.g. radar,
photographic, x-ray, whatever) and clearly alien artefacts.
This is a very high standard, but it is a fairly extraordinary claim and therefore I don't think this is too high a standard to set for "proof."
That said, something may be very likely without being proven, and I think that a preponderance of evidence would be much easier to accumulate.