New Cave Entrances Seen on Mars

Riding with Robots writes "The Mars Odyssey orbiter has come across what look to be openings to cavernous spaces under the surface of Mars. NASA reports the find is fueling interest in potential underground habitats and sparking searches for caves elsewhere on the Red Planet. These latest images follow other recent discoveries of intriguing places to explore. From the article: 'The find has led some to wonder if these or other caves on the planet may provide shelter to life or former life on the Red Planet. "Somewhere on Mars, caves might provide a protected niche for past or current life, or shelter for humans in the future," said Tim Titus of the U.S. Geological Survey in Flagstaff. These caves, however, likely never hosted life due to the extreme altitude of their location. "Even if life has ever existed on Mars, it may not have migrated to this height," said Cushing.'"

Comments

Dust-free caves on Mars?

[eskayp]

Not being a rocket scientist there is something I don't understand:
Why aren't the Martian caves filled with dust accumulated from the seasonal storms?
Are gases or vapors from within clearing the cave entries of dust?
( We would expect to see trails of ejecta. )
Are the caves so new or geologically young that they have not yet drifted full?
Are the caves at elevations above most of the Martian dust storms?
Layman's questions looking for non-tinfoil-hat expert answers.