The space expert also noted that not all UFO sightings can be "explained or denied", and said scientists should be more open-minded about the possibility of alien visitors.
Nasa has long been investing in SETI, the "search for extraterrestrial intelligence" - better known as aliens. And in a recently publisher paper on SETI, Professor Silvano P. Colombano suggested that alien life may have already visited us.
He suggested that aliens could look so different from how we expect, and that they may be able to travel huge distances - because we simply can't comprehend their make-up or technology.
"I simply want to point out the fact that the intelligence we might find and that might choose to find us (if it hasn't already) might not be at all be produced by carbon based organisms like us," said Professor Colombano, of Nasa's Ames Research Centre in California....read more>>>...
