Mars has some of the largest volcanoes in the solar system, but they’ve apparently been inactive for millions of years. No plumes of ash or flowing streams of lava are seen on Mars today. But just how long ago were the last great martian eruptions? That has been a matter of some debate among planetary geologists, and now scientists at the University of Arizona (UA) have announced new evidence for recent – geologically speaking – explosive volcanism in the Elysium Planitia region of Mars. According to the new findings, eruptions there may have occurred as recently as 53 thousand years ago, which is a blink of an eye relative to Mars’ total age of about 4.6 billion years (same as Earth’s). According to these scientists, this finding could mean Mars is still volcanically active even today, at least underground.