Re:Contradictory Statements? (Score 1)

Personally I wouldn't describe the Martian atmosphere as being "essentially a vacuum". It is very thin however. It's about .7 - .9 kPa. I believe this would be similar to being at 80,000ft on Earth. But there is enough of an atmosphere on Mars to cause everything from small dust devils to massive dust storms that cover a large portion of the planet.