Mars' history may be filled with explosive volcanoes

According to a new study published in the Proceedings of the National Academy of Sciences, Mars may have had explosive volcanoes at some point in its history. Such a conclusion comes via a sample the Mars Curiosity rover took of the landscape, with testing of the sample revealing that it contains a mineral commonly associated with explosive volcanoes: tridymite.

Evidence of volcanoes on Mars is nothing new, but thus far researchers have believed them to be of the less terrifying sort — the kind where molten rocks flows is steady streams versus the kind where they explode outward violently. This belief is spurred in part due to the lack of big shifting plates like the kind we have on Earth. However, this mineral has cast doubt on that assumption.

The sample was taken in a region of Mars known as the Marias Pass, which is apparently in the Gale crater. Rocks in that area caught researchers' eyes, with their appearance suggesting they may have silica in their composition. This spurred researchers to study samples of the rocks, which were gathered by Curiosity. An x-ray analysis of them revealed tridymite, and high levels of it.

However, knowing what they do about this particular basin — that it was once filled with a lot of water like a Martian lake — it seems likely to the researchers that the material ended up there from a river or stream feeding into it...and that the mineral itself may have ended up in the smaller bodies of water by being forcefully ejected from a volcano.

Assuming such explosive volcanoes did exist on Mars, researchers are left with the new task of reevaluating what they know and speculate about the Red Planet's early existence, as well as how such explosive volcanoes may form in the absence of tectonic plates.