Leo started with the basics. The book showed him how to use his hands to measure "degrees" in the sky—a fist held at arm's length was 10 degrees. Armed with this simple trick, he finally understood why the Big Dipper looked so massive some nights and tucked away on others.

He learned why it changed shape and how to spot the "seas" that were actually ancient lava plains.

By the time Leo finished the Seventh Edition, he wasn't just a guy looking at the sky. He was the person his neighbors came to during meteor showers. He could point out the Andromeda Galaxy—a smudge of light that was actually an entire universe of its own—and explain the expanding nature of space.

The book hadn't just taught him facts; it had given him a new set of eyes. Now, when Leo looked up, he didn't see a dark ceiling. He saw a home.