Why are all these "cute girls sometimes do the random hobby that's in the title, but usually they're just recycling each others vaguely humourous almost-jokes" 4koma manga so interchangeable? You could swap any two characters between any of these casts and nobody would notice a difference.
I'd disagree with the "all", but sadly I don't think this particular series provides a counter-example.
However, here's a little snippet of information for anyone who's curious about the identities of the asteroids shown on the volume 3 cover (admit it, you were desperate to know, right?). At top left: Itokawa. At top right: Ryugu. They're not just chosen at random; both of them have a Japanese connection, having been the targets of JAXA sample return missions. (The one at bottom right is Vesta. I seem to recall that it got a mention somewhere in the story, but I could just be imagining it. I already forgot most of what happened...)
Speaking of sample return missions, if you think the girls are cute, wait until you see the space probes:
Now that's what I call moe!