Well, I was thinking you could have a lander with a tether (high test fishing line or kite string) and battery powered fans. It would be like a small blimp I guess.

The point here is you could take pictures of the INSIDE of the canyon at arbitrary altitudes and actually see the real geology.

You may say wind would be a problem, but the momentum is proportional to mass, so since mars' atmosphere is so thin, I figure the strongest winds on Mars have momentum equivalent to about a 30mph wind on Earth. So the tethered flyer should be ok to go most of the time. With a tether you can control altitude much better than without a tether.

Of course, some problems are tangling and perhaps cutting on sharp rocks of the canyon wall.

Could it be done, or are there better options for aerial probes which may be able to explore the canyons?

To me the native canyons make more geological sense to explore than meteor craters, because they are presumably caused entirely by Martian forces, as opposed to cosmic impacts. This would mean the geology and mineralogy would be entirely Martian, so more useful for understand ages and past hydrology of the planet.

Thoughts?