A LEADING astronomer dismissed the notion today that aliens from other planets have been visiting us on Earth, claiming the distance is too vast for a spaceship to fly.

Dr Christian Kaiser, of the University of Southampton, said while it was possible life existed on other planets the “enormous” gap between us and the next Earth-like body would prevent the journey.

A spate of reported sightings of UFOs has led to renewed speculation that aliens were surveying the planet.

Speaking ahead of a public lecture later this month, Dr Kaiser, of the School of Physics and Astronomy, said: “There has been breathtaking progress in finding planets.

“The proof of life on another planet would be a huge scientific discovery and would also severely challenge our social, political and religious thinking.

“Planets comparable to Earth should have solid surfaces and may harbour life.

“However, the distances between stars in our galaxy are enormous.”