Science Alert: [2] For many years, we thought Mars was dead. A dusty, dry, barren planet, where nothing moves but the howling wind. Recently, however, pieces of evidence have started to emerge, hinting that Mars is both volcanically and geologically active.
[3] Well, the idea of a volcanically active Mars just got a little more real. A meteorite that formed deep within the belly of Mars has just provided the first solid chemical proof of magma convection within the Martian mantle, scientists say.
[4] Crystals of olivine in the Tissint meteorite that fell to Earth in 2011 could only have formed in changing temperatures as it was rapidly swirled about in magma convection currents – showing that the planet was volcanically active when the crystals formed around 574 to 582 million years ago – and it could still be intermittently so today.
[4] “There was no previous evidence of convection on Mars, but the question ‘Is Mars a still volcanically active planet?’ was previously investigated using different methods,” explained planetary geologist Nicola Mari of the University of Glasgow to ScienceAlert.
[5] “However, this is the first study that proves activity in the Mars interior from a purely chemical point of view, on real Martian samples.”
[6] Olivine, a magnesium iron silicate, isn’t rare. It crystallises from cooling magma, and it’s very common in Earth’s mantle; in fact, the olivine group dominates Earth’s mantle, usually as part of a rock mass. On Earth’s surface, it’s found in igneous rock.
[7] It’s fairly common in meteorites. And olivine is also fairly common on Mars.
In fact, the presence of olivine on the surface of Mars has previously been taken as evidence of the planet’s dryness, since the mineral weathers rapidly in the presence of water.

But when Mari and his team started studying the olivine crystals in the Tissint meteorite to try to understand the magma chamber where it formed, they noticed something strange. The crystals had irregularly spaced phosphorus-rich bands.

We know of this phenomenon on Earth – it’s a process called solute trapping. But it was a surprise to find it on Mars.