"Mars appears to be a cold, dry planet. Yet scientists have used technology to find evidence of water that once covered it. Now they want to know if Mars may have had living things in the past-and whether the planet could support life in the future! This book takes readers on an exciting out-of-this-world voyage and uncovers cutting-edge technology while supporting STEM and NGSS standards. Each book contains fact boxes, sidebars, a glossary, an index, and places to go for more information"--