I read the newer little gem edition with illustrations by Hannah Coulson.

Definitely a favourite early reader of mine.
Such a short and simple story but also with such fun and depth.
The illustrations were a beautiful addition and really helped work hand in hand with the story to engage the reader in a fun adventure to the moon.

For an adult, older or depper reader there's plenty to talk about in the subtext of the story, and for a new reader, it's a fun adventure with no intimidating pages full of text.