Martian Volcanoes Once Chose Violence

Structures in rocks imaged by the Spirit rover reveal similarities to ignimbrite rocks here on Earth, which means some very ancient eruptions were more explosive than expected.

IMAGE: Outcrop of olivine-rich bedrock in Gusev crater observed with Spirit’s Panoramic Camera (Pancam) in 2005. CREDIT: NASA/JPL/Cornell/ASU

We now turn to volcanos on Mars. And specifically, we’re going to talk about a point in time when some of…