I purchased this book for my five year old son, who loves anything that has to do do with outerspace and the planets. This is a terrific book for a young child, the information is direct and to the point and easy to understand. I think children in the older recommended age range would be somewhat dissappointed, it is not really meant for in depth understanding.
I agree with one of the editorial reviews that lauded the thematic organization over examining each piece as an isolated item-- it allows the child to understand the relation between each part of the solar system... overall, a very good introductory book.