D. Spires wrote:
I’m still not saying this is geothermal activity, Alex (now that I think about it, I think it was you who dumped all over it at MSNBC those years back),

Alex writes:
I do not recall "dump[ing]" on your theory over in MSNBC BBS, though I do recall offering an alternative plausible explanation that is substantially the same as the one I offered above. Positing that the MOC NA captured geothermal activity (i.e. "Dan's Smoker") is a fairly extraordinary claim, especially given what is known about Mars, requiring a great deal more than just one's interpretation of a single datum. In this respect, my explanation is just as legitimate, or valueless, as yours. Please do not interpret criticism as a dismissal. One of the attractions of this group is the fact real debate often takes place, rather than the slavish groupthink found in other boards, namely the anomalists, where everyone chimes in with "Great find! I totally agree with your analysis." Rarely does this approach result in scientific advance, which usually relies on exacting dissection and often contentious critique.

At any rate, interpreting the feature(s) as a "smoker" requires one to jump several hurdles. First, one needs to demonstrate that alternative explanations (such as the one I put forth) are implausible or incorrect. As I mentioned, conelike talus deposits, spurs, low albedo dust avalanche scars, etc., have been widely seen at other locales on Mars. One would have to put forth rather convincing evidence that Elysium Fossae is an atypical example demanding a different explanation. Also, one might wish to explain how a red wavelength camera like the MOC, which was designed to see through thin hazes, could image an apparently thick "smoker" on planet with such an insubstantial atmosphere, where gases would, at least according to physics, tend to dissipate almost immediately.

I'm not saying your interpretation is wrong; far from it. You could in fact be exactly right, but in my opinion such an assertion is not supported by the pertinent evidence or lack thereof.

D. Spires wrote:
I’m just saying what it appears to be to me. this is an interesting site and I hope for another set of pics.

Alex writes:
Perhaps, perhaps not. Remember that the image to which you refer was acquired during the first aerobraking phase, which involved vastly different geometries and associated illumination than can be acquired during the current mapping orbit. I can easily imagine repeat imagery of the locale to show different albedos and surface illumination that others may interpret as "the smoke has moved." To be a valid scientific assertion (i.e. geothermal activity) one has to provide, in accordance with the Scientific Method, a way to falsify the hypothesis in order to advance and avoid an inconclusive result.

D. Spires wrote:
Also, I set this little piece in to CBAT. It includes a description from none other than our own still-functioning geologist, Peter Ness.

Alex writes:
Although this sounds suspiciously close to an appeal from authority, am I included as well? I consider myself a "still-functioning geologist."

Alex R. Blackwell
University of Hawaii