Mars’s Most Mysterious Cloud Might Be Defying Textbook Cloud Physics

It may not be as obvious, but just like Earth, Mars has seasons. And every day of every summer, an 1,800 kilometer long thin white cloud appears to the west of Arsia Mons, a 20 kilometer high extinct shield volcano. At least for a few hours, before it dissipates until it reappears the next morning. Scientists have known about this feature, which they call the Arsia Mons Elongated Cloud (AMEC), for decades, but planetary scientists have been unable to explain it using traditional atmospheric models. But a new paper, published in Nature Geoscience by a research team led by Dr. Jorge Hernández-Bernal of the Sorbonne, suggests that the cloud could be the first documented real-world example of a cloud flash-freezing out of thin air.