Mars dust doesn't explain one of the solar system's weirdest clouds

Astronomers may have uncovered a wild reason for how one Martian cloud grows hundreds of miles longer than California, possibly making it the largest of its kind in the solar system. Astrophysicist Jorge Hernández Bernal first spotted the cloud in an otherwise clear sky in 2018. Images by the European Space Agency's Mars Express Visual Monitoring Camera, aka the Mars webcam, captured the strange phenomenon as the Red Planet's southern hemisphere experienced spring. When he looked through archival Mars images, he found…