Our nearest planetary neighbor has been the subject of endless fascination and wide-ranging theories throughout history. Is there life on Mars? Was there ever life on Mars? What was the atmosphere like thousands or millions of years ago? From Percival Lowell, who built his own observatory so he could dedicate himself to studying the red planet, to NASA landing the car-sized Opportunity rover in 2012, this eBook, Exploring Mars: Secrets of the Red Planet, traces Scientific American's coverage of the observation and exploration of Mars. The first section outlines early 20th century theories about Mars, including the possibility of an intricate canal system built by an intelligent species. Once the space probes enter the picture, most of those ideas were debunked, but even more questions arose. The second section covers current missions, which found evidence of ancient oceans and a thicker atmosphere that has since been lost. The third section raises even more exciting possibilities with ambitious plans for future missions. In this book, you’ll follow these advances in astronomy and planetary science as better and better technology brings us incrementally closer to unlocking the secrets of Mars.