The vastness of the universe - with its hundred billion galaxies and trillions of stars - means there could be other forms of life outside Earth, even intelligent ones, the Rev Jose Gabriel Funes, a Jesuit who directs the Vatican Observatory, says.

"How can we rule out that life may have developed elsewhere?" Mr Funes said in an interview with Vatican newspaper L'Osservatore Romano, headlined: "The extraterrestrial is my brother."

No limits on God

"Just as there is a multitude of creatures on Earth, there could be other beings, even intelligent ones, created by God. This does not contradict our faith, because we cannot put limits on God's creative freedom," he said.

"Just as we consider earthly creatures as 'a brother' and 'sister', why should we not talk about an 'extraterrestrial brother'? It would still be part of creation."

The full-page interview - printed in a question-and-answer format - ranged from discussions about the relationship between the Roman Catholic Church and science, to the theological implications of the existence of alien life.

No contradiction

Mr Funes mused that aliens would not have been visited by Jesus, because his "incarnation was a unique and unrepeatable event". However, "I am sure that they too, in some way, would have the possibility to benefit from God's mercy".

Mr Funes said that science, especially astronomy, did not contradict religion, touching on a theme often dealt with by Pope Benedict XVI, who has made exploring the relationship between faith and reason a key aspect of his papacy.

The Bible "is not a science book" and looking for scientific facts on the universe and its origin does not cast doubt on God's role in its creation, Mr Funes says.

As an example, he said he believed the Big Bang theory was the most "reasonable" explanation of the creation of the universe. The theory says the universe began billions of years ago in the explosion of a single, super-dense point that contained all matter.

And yet, "I continue to believe that God is the creator of the universe and that we are not the result of chance".

UK's Mulder

Meanwhile, the Ministry of Defence revealed it had recorded sightings of alien craft over Wallasey Town Hall and a saucer-shaped Unidentified Flying Object (UFO) hovering over Waterloo Bridge.

Nick Pope, who worked for the MoD for 21 years and was responsible for investigating the sightings said: "Most of the UFO sightings here are probably misidentifications of aircraft lights and meteors, but some are more difficult to explain."