When you're a parent of very young children you tend to have unrealistic expectations of what will constitute enjoyment for your children. Okay, having checked with my wife I now have to amend that opening sentence to say: "As a parent of very young children I tend to have unrealistic expectations of what my children will enjoy."

Take space, for example. All children enjoy space. The moon, stars, planets, comets, space rockets, aliens, black holes, galaxies. All that sort of thing. Kids love it.

With that in mind, and in a rare spurt of energy and organisation, I decided that the family would benefit from a trip to Harewood House where there's now a big planetarium. What's more, I discovered, they even do an under-fives session in which, I anticipated, all the stuff about the formation of nebulae and the relative mass differentials in the hearts of black holes would be given a backseat in favour of "LOOK AT THAT BUG-EYED MONSTER WHAT MIGHT LIVE ON MARS OR SOMEWHERE!!!"

I say anticipated because although the whole family did indeed ship off to Harewood House to visit the Yorkshire Planetarium at the weekend, I saw exactly three minutes of darkness and one projection of a tennis ball-sized moon before I had to exit stage left.

While four-year-old Charlie and his mum stayed on to listen to a doubtless gripping and informative story about a mole and his bid to be the first near-sighted rodent on the moon (I think), I had to accompany our two-year-old, Alice, outside after she threatened to scupper the launch of the whole event by bellowing "I need a wee!" at the sort of volume that would drown out a space shuttle's primary engines.

This wanting a wee thing isn't actually related to bodily functions at all. It's what Alice does whenever she's either bored of her surroundings, doesn't want to carry on what she's doing, or is simply interested in what's going on beyond any door or other barrier.

Because she's canny enough to know that we won't risk having the Yorkshire Planetarium or any other tourist attraction, restaurant or leisure facility flooded out, she's always guaranteed to get out of her boring situation or have a nosy where she's not meant to.

Alice is that kind of pro-active kid. If there's a difficult or awkward way of doing something, then that's the way she'll want it doing. Which, while annoying in the short term, is probably a good thing overall, because she's going to be the sort of girl who knows what she wants, knows how to get it, and doesn't take no for an answer.

Which is why, while everyone else was enjoying the story of the adventurous mole, Alice had negotiated herself to be the first on the bouncy space slide that all the other children would get to after they'd had their educational storytime. The look on her face as she tumbled about without anyone else on her way said it all: "Never mind moles in space, I've got this thing all to myself."

By the time Alice is a grown woman there might well be a lot more space travel than we have today. And if NASA is looking for a gutsy, decisive, individual who knows their own mind to lead a mission to the stars, then step aside Captain James T Kirk, because Alice Mae Barnett is the one they want on their side.

Hopefully, though, she might have sorted that bladder thing out by the time she's cooped up in a zero-gravity spaceship...