Martians Might Be Real. That Makes Mars Exploration Way More Complicated

History will note that the guy who discovered liquid water on Mars was an undergraduate at the University of Arizona, a 20-year-old who played guitar in a death-metal band and worked in a planetary science lab. One day, while comparing different satellite images of a single Martian crater taken at various times of year, he noticed something odd: a set of dark streaks in the soil that grew in the Martian summer and shrank in the winter.