Ancient Earth, Ancient SkiesHow old is Earth? How old are the planets, the Moon, meteorites, stars, and the Universe itself? How do scientists know these things? If youve ever asked yourself some or all of these questions, then this book is for you. Planet Earth and the other bodies of the Solar System are 4. 5 billion years old. They reside in a galaxy (the Milky Way Galaxy) that is 12 14 billion years old, and are part of a universe that is 13 15 billion years old. G. Brent