It's not a stupid question, when you think about it.

Why did Neil Armstrong and Buzz Aldrin restrict their moonwalk to barely 100 yards? After all, it was a once in a lifetime experience, even once in a blue moon. You might have thought natural curiosity would have convinced them to stray further afield. But no. As Armstrong has now explained, it was "really, really hot" up there; no one knew how the special suits would bear up, and Nasa wanted the experiments conducted in front of a fixed camera.

So there you have it. Health and safety and PR ruled even then, even there. More than 30 years on, Armstrong still describes his tiny, personal, deviation from the plan as "cheating", though he felt the potential gain was "worth the risk". A note of wistfulness suggests he would rather like to have another try. Is there no billionaire sponsor out there prepared to bypass Nasa and speed Armstrong spacewards again? As he says, there is more than 14 million square miles of lunar surface yet to be explored.