The head of astronomy at the esteemed university, Avi Loeb, even said that to suggest otherwise constituted “arrogance”. He explained to Express.co.uk: “About a quarter of all the stars have a planet the size of the Earth with the same surface temperature of the earth and potentially liquid water and the chemistry of life. So if you roll the dice billions of times, the number of stars in the galaxy, it’s very likely that they’ll be special or unique.

“And anyone that pretends otherwise is showing arrogance in my view. “I would say that primitive life is almost inevitable. “Because as soon as the Earth cooled microbial life started. “And just based on that fact I would think that the chemistry of life, if you provide the appropriate soup of chemicals and the appropriate temperature and other environmental conditions, then life will develop.”

Alien Life: Harvard professor Avi Loeb made the astonishing claims

Professor Loeb added that sophisticated alien lifeforms were also very likely to exist, as the leap between no life to primitive life was far more chemically complex than the jump between primitive and sophisticated aliens. Mr Loeb also outlined one simple way to discover otherworldly infrastructure. He started by explaining that the most common type of star by far is a relatively small Dwarf Star. He continued: “The planets in the habitable zone around the most common stars are tidally locked. “That means they always show the same face to the stars. “They have a permanent day side and a permanent night side. “And you might think that if there is a civilisation out there they would try to transfer heat and light from the day side to the night side.

“And one can tell if that happens because the faces of the planet as it goes around the star would look different. “If the dark side is illuminated artificially we would not see the same light curve. “And the same is true about the heat distribution across the surface of the planet. “So, potentially, if a planet is being terraformed by a civilisation, we could spot it without even imaging it directly - just by seeing the amount of light it would need or reflect and the amount of heat that we can read. “One can look for artefacts on such planetary systems, for example, cells might cover the surface of the planet and they might show up given that it is quite different from natural rock. “Or you could look for industrial pollution or some other industrial artefacts that are produced by civilisations.”

Professor Avi Loeb even claimed that it is indeed “quite possible” that we have already interacted with alien technology without realising. He explained: “It’s quite possible that we did detect some traces of other civilisations but haven’t recognised them. “The reason is we often imagine what we know already - what we have developed ourselves. “And until we develop the appropriate technology, we would not recognise it out there in the sky.” The venerable astronomer elaborated that there was nothing far fetched about the search for alien life.