Martian meteorites allow scientists here on Earth to decode that planet's geology, more than a decade before the first missions are scheduled to bring rocks back home from Mars.
It's established Mars was once a planet with surface-level water. So with multiple MARS missions starting next year, the key to seeking out martian life may instead lie in the contents of its 'dust'.
They erupted for billions of years and make Earth's volcanoes look like molehills. Here's what we know and what we don't know about them.