Ice covers parts of Mars, but scientists have long wondered: Does liquid water exist there too? All known life needs liquid water to survive. So detecting liquid water on another planet means that life could possibly exist there too. A spacecraft called Mars Express recently found evidence of an underground lake at Mars’s south pole!
Since 2003, the European probe has been studying Mars using radar. That technology sends out invisible vibrations called radio waves. Studying how those vibrations bounce off Mars and return to the probe gives scientists clues about what lies beneath the planet’s surface. The probe detected a lake three times the size of Manhattan beneath the ice at Mars’s south pole.
“The discovery raises several questions,” says Jonathan Lunine, a planetary scientist at Cornell University in New York. One of the most exciting of them is “Could life exist in that lake?”