# Why is ice on Mars not covered in dust?

There's exposed water ice on Mars, like in craters like this

At the same time, Mars has dust storm, covering the solar panels of rovers, and occasionally covering the entire planet

So why is this ice not covered in dust?

I understand that dry carbon dioxide ice can maintain a clean surface, as it's seasonally sublimated into the atmosphere and re-deposited, but how come water ice (at least some of it) is also left clean?

• Because water ice also sublimates? Water follows a similar seasonal cycle on Mars as $CO_2$. We can for example, follow the water ice ring that forms around the polar caps. – AtmosphericPrisonEscape Sep 22 '19 at 21:40
• @AtmosphericPrisonEscape Perhaps you mean " because water also freezes out of the Martian atmosphere" ? – Carl Witthoft Sep 23 '19 at 18:11
• who says it isn't, at times? On earth, ice gets covered in dust, and then the wind picks up and the dust gets blown away. No reason to believe the same isn't happening on Mars. – jwenting Sep 24 '19 at 7:53
• Frost at the Viking two landing site (1976): planetary.org/multimedia/space-images/mars/… – Wayfaring Stranger Sep 26 '19 at 17:00