Since Sept. 13, the European Space Agency’s Mars Express has been observing the evolution of a curious cloud formation that appears regularly in the vicinity of the 12.4-miles high (20 km) Arsia Mons volcano, close to the planet’s equator. This photo was taken on Oct. 10 when the cloud extended some 930 miles (1,500 km). ESA/GCP/UPV/EHU Bilbao, CC BY-SA 3.0 IGO
There’s a very cool cloud on Mars right now. It’s downwind of an ancient martian volcano named Arsia Mons. What makes its such a head-turner is that it perfectly mimics a plume from a volcanic eruption. Naturally, it’s become the subject of much online speculation. The European Space Agency’s orbiting Mars Express has been taking photos of the feature since September. I checked today and it’s still there as of Oct. 24.
I wish it were a live eruption, a volcano come to life after millions of years of dormancy. How exciting that would be. But that’s not the case. Arsia Mons last erupted between 250 to 10 million years ago with peak activity occurring 150 million years ago. It’s been chillin’ ever since with no visible sign of volcanic activity.
This water ice cloud, which forms as air ...