It’s not volcanic activity, and it’s definitely not from a fire.
Mars, our red planetary neighbor, is a vastly different world from Earth.
Mars’s atmosphere is too sparse (0.007 bar) to allow fresh water on its surface.
There’s also practically no free molecular oxygen (O_2) there, as it’s only produced by ultraviolet radiation striking carbon dioxide.
Without those ingredients, how can we explain these apparent plumes of smoke on Mars?
On Earth, such plumes typically indicate one of two things: fires or volcanic eruptions.
Without carbon-based material or copious amounts of available oxygen, we can rule out fire.
Mars possesses the Solar System’s largest volcano in Olympus Mons, but it appears to be extinct.
Although there is some circumstantial evidence that Mars may be volcanically active, we’ve never witnessed an eruption.
Instead, these plumes are a simple atmospheric phenomenon: clouds.
Mars has water vapor just like Earth, which circulates through the Martian atmosphere.
As the air climbs into cooler, low-pressure regions to rise above intervening mountain, it cools.
If that air cools sufficiently, it drops below the dew point, forming mountaintop clouds.
With rapid winds in its low-density atmosphere, Martian clouds can persist for hundreds of kilometers or more.
The atmospheric phenomenon responsible, lee waves, occur on Earth, too.
Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words. Talk less; smile more.Ethan Siegel is the author of Beyond the Galaxy and Treknology. You can pre-order his third book, currently in development: the Encyclopaedia Cosmologica.