Brian May doesn't believe in aliens.

The Queen guitarist has a PHD in astrophysics and is fascinated by space and although he'd love to discover proof of extra-terrestrials he thinks Earth maybe the only life-giving planet in the Universe.

In an interview on UK station BBC Radio 2, he said: ''I think it's possible that we're alone. I think it's possible that the life event was just a one off.''

Through his space studies, the 68 year-old musician - who is also vice-president of animal welfare charity the RSPCA - just isn't convinced there is another planet similar to Earth with the right conditions for giving birth to complex lifeforms.

He added: ''I don't think there really is a matching planet. Everybody jumps on these things, 'Oh there might be life out there', but, so far, no.''

Brian - who is married to actress Anita Dobson - recently had a ''magnificent'' time at NASA with the team who sent the New Horizons probe to Pluto.

The rocker was ''invited as a collaborator'' to the space agency's headquarters in Washington D.C. and admits it was an experience he will never forget.

He said: ''I was able to put together the first ever stereoscopic picture of Pluto. You see when we were kids it was a dot in the sky and nobody had any idea what it looked like, and suddenly you had these wonderful images coming back from the New Horizons probe as it scuds past it at 31,000mph, and I was there when these images came in and was able to put some together and it was a real thrill for me.''