Sir Patrick Moore talks to Steve Pratt about finding life on Mars and why his latest lecture tour may be his last.

ASTRONOMER Sir Patrick Moore will be leading people on a mission to Mars this month - from the comfort of their seats at York Grand Opera House.

The man who's earned a place in the record books for presenting The Sky At Night on BBC1 for 47 years will be on stage at the theatre to talk about Mars: The Final Frontier.

This, apparently, is the hot topic in astronomers' circles. "It's the year of Mars. It has been as close as it can ever be," says Moore. "We are sending rockets there and looking for life. We'll find if there's life on Mars, and I don't mean little green men."

His own view is there's a 50-50 chance of discovering life on the planet. "I can't be sure," he adds.

What is certain is that if evidence of life is found on Mars, it means that it could exist elsewhere, too. Sending up a one-man spacecraft to bring back samples, as is planned, could settle the argument once and for all, Moore believes.

His visit to the York theatre aims to introduce his audience to the Mars story, taking in such topics as manned missions, permanent bases and eventual colonies.

Lack of mobility, which prevents the 80-year-old from handling his telescope anymore, means he's thinking about putting an end to these personal appearances. He'll complete the current tour and may well make next year's tour his farewell one.

The Sky At Night, which was first seen on BBC TV screens in 1957, carries on and is now filmed in Moore's own study as he's unable to travel as much as he used to.

"I had no idea the series would last so long. It was impossible to say. No one knew whether people would take to it. Then, after ten years, we were pretty well established," he says over the phone from his Sussex home.

There are still plenty of subject matters for the programme to delve into. It's more a case of what to leave out, he says.

His illness prevents him pursuing some of his loves these days, such as playing the piano and the xylophone. "It can't be helped. I had a long run," he says philosophically.

Moore's own passion for the skies began at an early age, and saw him become a member of the British Astronomical Association at 11. After serving as a wartime navigator in the RAF, he was commissioned to write his first books on space and set up his own observatory.

The public hasn't lost its appetite for space. His lecture tours - Mars: The Final Frontier is his fifth - still pack venues around the country. Some 900 people turned up in Nottingham, he points out proudly.

* Mars: The Final Frontier is at York Grand Opera House on Monday at 7.30pm. Tickets: 0870 606 3595.