People celebrating the achievement of landing a probe on a comet are blind to the real purpose of the mission - to investigate a nest of aliens.

People celebrating the achievement of landing a probe on a comet are blind to the real purpose of the mission - to investigate a nest of aliens.

That's according to reports circulating among UFO watchers who are convinced the truth behind the European Space Agency's £1 billion Rosetta mission is "out there".

One email from an anonymous "whistle blower" within ESA claims intelligent-sounding signals were received from comet 67PChuryumov-Gerasimenko 20 years ago and the object is actually an alien ship in disguise.

The email, published on the website UFO Sightings Daily, says: "Do not think for ONE MOMENT that a space agency would suddenly decide to spend billions of dollars to build and send a spacecraft on a 12-year journey to simply take some close-up images of a randomly-picked-out comet floating in space ..

"Comet 67P is NOT a comet .. "

The whistle blower, who insists on remaining anonymous for fear of reprisals, insists the comet "is only being disguised as such" and appears able to change trajectory at will.

The letter adds: "As for who is disguising it and why I cannot answer. All I can tell you is that whatever this thing is it does show signs on its outside of machine-like parts and unnatural terrain ..

"Whatever this object is it did not ask to be found or scrutinised. And it appears for good reason."

Others spoke of "alien structures" in images of the comet, in particular a bright white "metallic" disc on or hovering above the 2.5 mile-wide lump of ice and dust, and a sculpted non-human face.

ESA unwittingly sent the speculation into overdrive when it disclosed that the comet was "singing". Clicking oscillations in the object's magnetic field, below the range of human hearing, sounded strangely tuneful.

Another post from "ex-naval electronics warfare technician" Carl Blackman on the website BPEarthWatch says: "Definitely not a natural signal, there is intelligent based stuff going on here."

On the same site, ImTheDaveman says: "This signal is very much a non-natural source .. The irony of Rosetta being sent there is too strong a coincidence.."

Another post on UFO Sightings Daily argues that the signal "had to have been made for humanity". It adds: "Is it a message of greetings? Or is it a warning of what's to come? We the people of the world need to find out."