Britain’s Astronomer Royal, Prof Lord Rees, says that if we were to make contact with extraterrestrials from outside our solar system, it would be with intelligent machines, rather than with organic aliens.

While addressing an audience at the Cheltenham Science Festival last week, Rees said that an incoming SETI-like signal would likely be from machines built by a previous extraterrestrial civilization, since machines would be more suited to the rigors of space travel, as opposed to their biological creators, who are likely to have died out long beforehand.

“I think it is quite likely that within a few centuries the overriding intelligence will be machines because they will have an easier time spreading beyond the Earth because they are not organic and most exploration will be by machines and not humans,” Rees said. “If you were to detect a SETI (Search for Extra Terrestrial Intelligence) signal it would be far more likely that it would be from a machine and not an organic creature. There has been just a thin sliver of time when organic beings have existed and billions of years after machines will take over, so they will be the future.”

Professor Lord Rees predicts that our own species will evolve into a "post-human" era: as the difficulties of space travel will require us to adapt our bodies, “That will be the start of the post-human era because they will evolve to be a new species."

Whitley Strieber comments: "In my book Transformation, I commented on the oddly perfect movements and sounds of the visitors. Nevertheless, despite my own and many others experiences, it should be remembered that Professor Rees is correct, first contact has not yet occurred, at least not openly. It still seems possible, in my mind, that some unknown form intelligence may be involved in the apparitions being reported, but obviously not in the way commonly assumed."