When you think of Mars, you probably picture a red, desolate planet with nothing moving on its surface. Indeed, that picture is accurate. But it wasn’t always that way. The Red Planet used to be bright red, and yellow, and orange – it featured a number of active volcanoes millions of years ago. And one ancient volcano has given scientists a surprising new look into Mars’s geologic history.
There is a huge shield volcano on the surface of Mars called Arsia Mons. Arsia Mons has long been inactive, but scientists are now speculating that its last eruption may have closely coincided with the extinction event that killed off the dinosaurs. Nobody is suggesting that the two events are related, but it’s fascinating to think that there was active volcanic activity on Mars so recently in geologic time.
NASA’s Goddard Space Flight Center has issued a press release claiming that a team of researchers, helmed by Jacob Richardson, have concluded that Arsia Mons’ peak activity was 150 million years ago. This would have coincided with the Jurassic period of the fossil record. Arsia Mons stopped erupting at roughly the same time the dinosaurs stopped breathing.
The Arsia Mons volcano is found close to the equator of Mars. It’s at the southernmost point of the Tharsis Montes range, which includes two other shield volcanoes. Arsia Mons is enormous – its caldera is large enough to hold the water of Lake Huron, with change.
NASA has spotted 29 volcanic vents in Arsia Mons’s caldera, after analyzing images taken by the Mars Reconnaissance Orbiter.
The oldest known lava flows in the caldera are placed at around 200 million years ago. And the most recent are about 50 million years old. The imagery also yielded estimates of each flow’s volume. At the height of the volcano’s activity, it produced about one to eight cubic kilometers of magma every million years. Richardson described it as “a slow, leaky faucet.”
The new insights into Mars’s volcanic history will give us a better picture of the planet’s geology. Hopefully we will be able to construct a more accurate picture of Mars’s interior structure. Jacob Bleacher, one of the study’s co-authors, says that the new findings are a step towards the Martian volcanology community’s major goal, of more comprehensively understanding the planet’s volcanic history.
The study was published in the scientific journal Earth and Planetary Science Letters. Hopefully there will be more new findings on the horizon.