1 Young Jamie: So tell us about your ancient and noble Martian civilisation.
2 Martian 1: Do you know how hard it is to get a decent frozen yoghurt here?
3 Young Adam: Um, no.
4 Martian 2: I'll give you a hint. We have no cattle.

Apparently there's also soy yoghurt, but I doubt they grow many soy beans on Mars either.

Is there any food you can't make out of soy beans?? I'm sure there must be soy strawberries out there somewhere.