Nine planets and countless other objects revolving around our Sun make up the Solar System. As astronomers discover more about these heavenly bodies, including our own planet, Earth, they are also finding further mysteries and extraordinary space puzzles. But our Solar System is just one of billions in the vastness of our galaxy, the Milky Way. And the universe itself contains countless ever-changing galaxies. The breathtaking photographs and detailed illustrations in this book take you on a whirlwind tour of our Solar System and beyond, while the text and reference sections provide a wealth of essential information.