Back to work, Post-hiatus but pre-entry Options

[fredk]

I think the return to driving deserves a new topic for Oppy. According to this new release, Oppy is back up to 300 Whrs, and had a small cleaning event!

The release also gives a surprizing reason for the drive to the rim:

One reason the rover team chose to drive Opportunity closer to the crater rim was to be prepared, if the pace of dust accumulation on the solar panels increases, to drive onto the inner slope of the crater. This would give the rover a sun-facing tilt to maximize daily energy supplies. The drive was also designed to check performance of the rover's mobility system, so it included a turn in place and a short drive backwards.

That explains why they drove to this point on the rim - if they enter they'll face south, as it's still southern summer.

[dvandorn]

I understand you're teasing, Brian, but, just for the record...

Dust devils are very specific weather phenomenah. The definition requires the formation of vortical wind structures large and energetic enough to raise surface dust into the air. Dust devils, again by definition, are visible as funnel-like or rope-like structures due to the dust entrained in their vortical structures.

Dust devils do not leave broad fan-like surface markings -- they tend to leave sinuous, worm-like tracks which do not vary in width by more than 20% to 30% along their lengths. The dust streaks emanating from Victoria begin at wind-stricture points along the crater wall and fan out to be several hundred percent wider by the time they fade to invisibility.

Calling every erosional or depositional wind event on Mars a dust devil is like calling any energetic wind event on Earth a tornado. It's an extremely poor, misleading, and just plain incorrect use of the term.

All that said, I'm really not as anal about this as it sounds. I just want to state the case clearly, and hopefully establish a level of terminology use on the forum that maintains us at an "impressively high level."



-the other Doug

[Guest_Edward Schmitz_*]

I understand you're teasing, Brian, but, just for the record...

Dust devils are very specific weather phenomenah. The definition requires the formation of vortical wind structures large and energetic enough to raise surface dust into the air. Dust devils, again by definition, are visible as funnel-like or rope-like structures due to the dust entrained in their vortical structures.

Dust devils do not leave broad fan-like surface markings -- they tend to leave sinuous, worm-like tracks which do not vary in width by more than 20% to 30% along their lengths. The dust streaks emanating from Victoria begin at wind-stricture points along the crater wall and fan out to be several hundred percent wider by the time they fade to invisibility.

Calling every erosional or depositional wind event on Mars a dust devil is like calling any energetic wind event on Earth a tornado. It's an extremely poor, misleading, and just plain incorrect use of the term.

All that said, I'm really not as anal about this as it sounds. I just want to state the case clearly, and hopefully establish a level of terminology use on the forum that maintains us at an "impressively high level."



-the other Doug

I agree with your sentiment about establishing a high level of dialog.

By websters definition of dust devil - a small whirlwind containing sand or dust - it doesn't have to be very big. My major point from above is that not having evidence does not exclude dust devils as the causative agent. Our ability to monitor the wind activity in Meridiani is almost zero. The fact that we don't see surface prints could be due to the sensitivity of our instruments or that they just don't leave a visible trail. Dust devils on earth don't always leave a trail. That we haven't spotted any with the rovers may establish a upper limit on their frequencey but doesn't rule them out.

We've become very familiar with the behemoths that leave visible trails from space. This isn't necessarily the norm. I still am in the not very likely camp. I just don't see that it's been established that there is no D D activity in Meridiani.

I will concede that we shouldn't be calling phenomenon by the wrong name.