Dss (8 and 10 space mad) like [[http://www.amazon.co.uk/Childrens-Atlas-Universe-Readers-Digest/dp/1575843730/ref=sr_1_1?ie=UTF8&s =books&qid=1195071702&sr=8-1 The Children's Atlas of the Universe]
But ds1 particularly likes What's out there - foreword by Stephen Hawking, his hero!
It has the most amazing (and most up-to-date) photos and images of the universe, along with various facts and information. I enjoy the pictures, ds1 enjoys both!
But it isn't actually aimed at children, so may not be what you are looking for.
The "see what's inside" feature on Amazon gives you a bit of a flavour, but doesn't give you a real feel of the quality of the publishing, and the mesmerizing nature of the pictures. It is also a very large books, with usually double-spread pictures, which you don't pick up from the Amazon pictures.
Anyway, we like it. A lot. Can you tell?