Mysteries of the Universe; Ex-Library; 13 oz.; 70 pages; 1st ED Ex library Good+ HC w/DJ in nice clean/tight condition 1 smudge title o/w looks very nice. Mysteries of the Universe Series. How old is the Earth? What is the Earth Clock? What is acid rain? From the bottom of the sea to the top of Mt Everest, scientist have probed and analyzed our planet. But Earth-with its uncertain origins, unpredictable volcanoes, and uncharted oceans-has largely remained a puzzle.