Water vapor in the Earth's atmosphere can turn into snow, then why would not the water vapor in the atmosphere of Mars be able to turn into snow?
I am not arguing about the spots in the picture, they may or may not be "snow" in that sense of the word, I am simply wondering how "scientific" methods can be used to detect snow fall on Mars, or what objections there are for snow falling on Mars.

Other musings.
There is iron and chloride on Mars. Ferric chloride on Earth can form long crystals....... Hmm..... But then how did the ferric chloride form on Mars, same as how did the methane form on Mars.

Veery interestink.

Johannes