I purchased three sets of books on the planets for my students to use as they did a research project during our astronomy unit. I have to say that this set was my least favorite. The text is written in something like 36 pt font, so there are perhaps 100 words total in the 24-page book.
The only thing I found useful was the last page of each book that had a summary of facts about the planet.
I liked this book. It had a lot of interesting facts that I didn't know. I would have liked it more as a grade school student because I would be so mind boggled by the facts and consumed by the illustrations. Perfect for helping with a grade school report or even high school to get a few interesting and easy facts.