He mapped the moon, so he was more than an enthusiastic amateur. Was he a great communicator? Well watch him in conversation here, with this nit who claims to be receiving messages from extraterrestrials: he's hilarious but also scrupulously polite, and there's nothing dishonest in the refusal to pull the guy up, because that's not his role.
Yet another voice of space
It actually takes two to communicate. By never forgetting that, Patrick Moore pioneered "interactivity" before the word was even needed. (It wasn't needed because, once, that was simply how people behaved.) It's more than politeness being displayed in this clip though, it's grace. Communicating this grace is what made Patrick Moore so great, because he was also communicating through it what television could be and be regularly. There's a lot to be said for keeping things human-scale and human-shaped, even if those things do then go and die. Night night, magic.