SIR Patrick Moore has his eye on Mars in his latest lecture tour but he is more immediately concerned with matters closer to home.

"Can we conquer Mars? We should do if all goes well. It depends on us governing ourselves responsibly and having no more stupid wars," says Sir Patrick, and he doesn't mean Star Wars.

At the Grand Opera House in York on Monday, on his fifth national lecture tour, the 80-year-old astronomer will address the theme of Mars: The Final Frontier.

An anxious David Bowie once posed the question "Is there life on Mars?", and Sir Patrick will answer it thus: "Yes, there may life of a kind there, life in the form of single cells, but not little green men.

"Our galaxies contain a hundred thousand million stars, and many of those are planets, and so life could appear, but if there is a chance of life on Mars, it would be primitive.

"With our scientific work, we know what conditions are like there; we know what can happen; we know what can't happen. We know there isn't surface water on Mars, so the key thing, if we are to find life, is that it will be underground in water. "

He does foresee manned missions to Mars, maybe as soon as 20 years hence. "It could go ahead by then, but it depends on science and possibly on politics and finance. One more silly war will end it all."

Twice now, he has mentioned his aversion to war (without directly referring to the Iraqi conflict). He finds solace in the work of the international space agency. "Who knows if we'll establish colonies on Mars; if we continue this way we will not survive, and if we don't pull together we won't deserve to get there, but the good thing is that space research is international," Sir Patrick says.

"The international space station has always been totally free of politics. Even the Chinese are coming in now, and they used to shoot astronomers under Chairman Mao."

Shoot astronomers, Sir Patrick? "It was a mistake," he says.

On a more positive note, 2003 is the Year of Mars, when Mars will be as close to Earth as it will ever be - only 34.5 million miles away - and a probe is on its way there, destined to land on Christmas Day.

Why, out of all the planets, is Mars such an abiding object of fascination?

"The reason it is fascinating is that it's the one place there's a chance of finding a primitive life form," Sir Patrick says. "But you'd have to be very careful in bringing that life form back here. Remember The Quatermass Experiment! Look at it in space first. It's much safer that way!"

Sir Patrick Moore presents Mars: the Final Frontier, Grand Opera House, York, Monday, 7.30pm. Tickets: £15 on 0870 606 3595.

Updated: 09:57 Friday, November 21, 2003