Asterpoids and viruses could be weaponised by invading aliens hellbent on colonising Earth to bleed the planet dry of its resources, according to a wild new theory.

Professor Paul Springer, from the US Air Command and Staff College in Alabama, spoke to Sun Online about a theoretical extraterrestrial attack.

The expert, who specialises in the changing face of war, said it's likely probes would be sent ahead of the invaders from beyond our solar system to scope out Earth.

Renewed interest in UFOs has surged following the publication of a landmark Pentagon report in June that saw the US admit for the first time there is something in their skies they cannot explain.

And the Congress and Senate have now voted through a plan for a new dedicated UFO office to probe the phenomena.

But should aliens actually invade, Prof Springer believes they would colonise planet Earth in an eerie echo of how Europeans colonised the Americas 300 years ago, with resources bled dry and indigenous people wiped out. 

He told The Sun Online: “You have to assume any civilisation is acting in what it perceives to be its own best interest — they are not showing up because they want to be benevolent.”

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