Astronomy; Miscellanea

2 titles from eBooks.com
Many Skies: Alternative Histories of the Sun, Moon, Planets, and Stars

Many Skies

Alternative Histories of the Sun, Moon, Planets, and Stars

US$28.95

What if Earth had several moons or massive rings like Saturn?  What if the Sun were but one...

924 Elementary Problems and Answers in Solar System Astronomy
US$19.00

This challenging collection of problems is organized into seven carefully crafted, thoughtful...