Giant eruptions billions of years ago left behind huge craters
Arizona State University, GSFC and JPL/NASA
Lava-spewing supervolcanoes ripped through Mars’ dusty red surface billions of years ago, a new analysis suggests.
Scientists have identified Martian volcanoes before, but none as violently explosive as the ones Joseph Michalski of the Planetary Science Institute in Tucson and Jacob Bleacher of the NASA Goddard Space Flight Center in Greenbelt, Md., report in the Oct. 3 Nature. “What we’re looking at is a very different beast,” says Bleacher.
When supervolcanoes erupt, they blow their lids completely, ejecting massive amounts of molten rock. Instead of leaving behind mountains of rubble, supervolcano explosions gouge giant craters into a planet’s surface. Because asteroid craters also pockmark Mars, scientists had assumed most of the pits were caused by impacts.
But some craters looked suspicious: They lacked typical impact signatures and were surrounded by ridges of