Starry Messenger by Peter Sis

From the publisher:
In every age there are courageous people who break with tradition to explore new ideas and challenge accepted truths. Galileo Galilei was just such a man--a genius--and the first to turn the telescope to the skies to map the heavens. In doing so, he offered objective evidence that the earth was not the fixed centre of the universe but that it and all the other planets revolved around the sun. Galileo kept careful notes and made beautiful drawings of all that he observed. Through his telescope he brought the starts down to earth for everyone to see. By changing the way people saw the galaxy, Galileo was also changing the way they saw themselves and their place in the universe. This was very exciting, but to some it was deeply disturbing. Galileo has upset the harmonious view of heaven and earth that had been accepted since ancient times. He had turned the world upside down.

While this book is recommended for age 4-6, because much of the text is at strange angles and written in cursive most children will have a great deal of difficulty reading it to themselves.