"First Light, The Search for the Edge of the Universe" by Richard Preston
A Child's Introduction to the Night Sky, by Michael Driscoll
Constellations Activity Book (Color and Learn), by Ryan Jacobson
Cosmic Odyssey: How Intrepid Astronomers at Palomar Observatory Changed Our View of the Universe, by Linda Schweizer
Find the Constellations, by H.A. Rey
How I Killed Pluto, and Why It Had It Coming, by Mike Brown
National Geographic Kids Readers: Planets, by Elizabeth Carney
Palomar Mountain (Images of America), by Brad Bailey
Simply Astronomy
Space!
Stars and Planets (Peterson Field Guides), by Jay M. Pasachoff
The Perfect Machine: Building the Palomar Telescope, by Ronald Florence
There's No Place Like Space (Cat in the Hat's Learning Library), by Tish Rabe