Huge landforms on Mars may have been caused by mud, not lava

The Martian surface is covered with thousands of lava-like flows similar to the kind we see from volcanoes on Earth. Questions have remained over what these flows are made of — were they the result of lava or something else entirely? A new study out of Lancaster University has settled the question, pointing to massive floods that happened in Mars' distant past.

According to the new study, these lava-like landforms on Mars were created by mud and the unique way it interacted with the Martian environment. Unlike on Earth, where the mud would spread out in large pools, the researchers found that it sort of 'piled' on itself and formed narrower, rounded channels that snaked out from the central pooling region.

The video above shows European researchers simulating this mud movement using a chamber that simulated the Earth's environment and the Martian environment. Both low pressure and extremely cold temperatures were used to simulate Mars, resulting in free-flowing mud that produced a very different result compared to simulated mudflows on Earth.

According to the University, these landforms may have been created by massive floods — ones akin to the biggest recorded on Earth — that etched huge channels in the Martian surface. These floods would have caused the water to seep into the Martian subsurface. That water may have then emerged later on as mud from ruptures in the frozen crust; the mud would quickly freeze and form its own icy crust, producing the landforms.

This same process may also explain formations spied on planets like Ceres, according to the study. Researchers haven't yet navigated a rover to one of these flow spots on Mars, meaning we don't yet know for sure what they're made of.