[mikeash]

There is, to a first approximation, no atmosphere on Mars. To a slightly better approximation, there is an atmosphere on Mars, but only enough to cause trouble, not enough to actually be useful for anything.

[wtracy]

There's enough atmosphere for Nasa to seriously consider deploying airplanes: http://en.wikipedia.org/wiki/Mars_aircraft

[stephengillie]

We've had the discussion: https://news.ycombinator.com/item?id=4261806

A cessna would need wings as large as a 747 and be traveling about mach 1 to take off, iirc.

[skeletonjelly]

Thats an awesome metaphor! Going to use this one, thanks.

[DiabloD3]

So it would need wings that have ten? times more surface... that doesn't mean this couldn't be done using small scale drone designs.

[JonnieCache]

Mach 1 where?

[goodcanadian]

Mach 1 always means the speed of sound in the local environment.

[stephengillie]

On Mars. Mach, the speed of sound (vibrations), varies with changes in heat, density, etc.