Similarly to the Earth, Mars also has numerous volcanoes. As a matter of fact, this planet hosts the largest volcano in the Solar System – Olympus Mons.
Recent scientific evidence suggests that Martian volcanoes are not only gigantic, but they actually differ from those on our planet in the duration of their eruptions.
In 2012, a rare meteorite, weighing merely 0.2 kilograms (7 ounces) was found in Algeria. It was called Northwest Africa (NWA) 7635, and despite being extremely small, it did reveal interesting facts about Martian volcanoes.
After careful analysis, the tiny rock was dated back 2.4 billion years ago. Of the 100 meteorites identified as originating from Mars, only 10 belonged to the same group as NWA 7635. All of the rocks have been dated at about half billion years old.
In a statement, Marc Caffee, Professor of Physics and Astronomy at Purdue University and a member of the research team, said: “We’ve never seen anything like that on Earth,”.
All the 11 meteorites, including NWA 7635, were exposed to cosmic rays for a period of 1.1 million years. However, the age gap between the other 10 and NWA 7635 indicated that there was a period of at least 2 billion years where one particular volcano was erupting.
“What this means is that for 2 billion years there’s been sort of a steady plume of magma in one location on the surface of Mars,” Caffee expained.
“We don’t have anything like that on Earth, where something is that stable for 2 billion years at a specific location.”
Although the scientists can’t confirm that the meteorites derived from Olympus Mons or another volcano, it’s very likely that they did. Olympus Mons rises 17 miles (27 km) in height and has a footprint nearly the size of Germany.
The fact that there are no plate tectonics like those on Earth accounts for the enormous size of volcanoes on Mars.
In the past, Mars used to be more like the Earth, as it too had tectonic plates that ground past each other forming craters and volcanoes according to NASA. But, Mars cooled down at some point in history allowing the molten rock beneath the plates to solidify. This in turn caused the tectonic plate formation ground to a halt.
As there is currently no geological movement on this planet, eruptions go uninterrupted by the crust shuffling around. Despite the fact that scientists have never walked on the red planet, they can study its surface with the help of these meteorites.
In addition, the gravitational force on Mars is much lower. This along with the planet’s thin atmosphere makes it easier for rock fragments released during impacts to leave the planet’s surface.
These fragments often orbit in space for hundreds of thousands, sometimes millions, of years, before their journey is interrupted. Only some of them land on our planet, a process which also takes thousands of years.