This undated image provided by NASA shows a high-resolution view of a possible ancient supervolcano on Mars. A new study published in the journal Nature
This undated image provided by NASA shows a high-resolution view of a possible ancient supervolcano on Mars. A new study published in the journal Nature found several irregularly shaped craters in the Martian northern highlands that scientists believe are giant volcanoes that spewed ash and lava billions of years ago. (NASA/Associated Press)