Well, yeah -- no threat to a deployed rover on the ground. The team *was* a little worried about dust devils (and high winds in general) at Gusev during EDL, though, according to reports I've read.

It appears that the dust devils are something of a seasonal phenonemon, since we hadn't seen much trace of them throughout the Martian fall and winter. But now, during early Spring, there are a lot of them.... we need to remember that in future mission planning, I think.

-the other Doug

You and me both! I'd dearly like to see the Tycho rim where the horrible joins between the frames don't dominate. I daresay it might be the most fascinating and beautiful lunar vista ever captured by cameras -- I can't wait to see Phil's work!

-the other Doug

Not any more...

-the other Doug

I thought that was what the three-bean casserole was for...

I better watch those comments, since some people take methane on Mars seriously...

-the other Doug

I'll believe that when I see the dust devil tracks spell out "NO KILL I"...



-the other Doug

I am totally blown away. This is what I mean about seeing alien vistas.

BTW -- the Sol 456 event (I think it was, the middle one of the first three Doug posted) seemed to pass rather close to Spirit. Does anyone know whether or not the solar panels were affected, either way? I mean, the devils pick up dust, but they also look like they could drop dust in their wake, too. Considering how quickly the air thins out with height, I'd think that small devils like these might be dropping dust fairly close to their paths. I'm hoping we don't get showered with so much dust at any point that power levels drop as fast and far as they rose after the first major cleaning event...

-the other Doug

Might want to put some really hot coffee in that thermos with your lunch, though -- remember, it's pretty chilly out there.

-the other Doug

I'll second that.

-the other Doug

Interesting... it always looked to me like these thrust faults were very similar to the wrinkle ridges on the lunar maria, and that, as such, they were a result of the (relatively) heavy lavas compressing under their own weight. In other words, that they were an artifact of the lava fill and not pre-existing of them.

But yes, I do see the orientation of the north-south trending faults, and in fact the one main fault line does extend beyond Gusev into the non-lava-filled ancient cratered terrain to the north.

I stand corrected... *smile*...

-the other Doug

In re your point 1) -- really? I'm not disputing, certainly, I've just never seen compressional stress features when I've looked at all the various images of Gusev and its surrounding region. I would assume the features we're talking about look, at the surface, like low ridges as opposed to graben?

On point 2), yeah, sedimentary rock does form at angles (people *do* need to remember that sedimentary rock forms in all sorts of ways, and water deposition is only one of those ways). I just think that Gusev's features, taken at a gross level, really do suggest that it was a lake at some point in the past, and applying Occam's Razor, it's simply more likely that layered sediments were water-deposited. But, of course, we'll be able to tell a lot better when we've gotten a really good look at the rocks in this outcrop.

And on point 3), I'm also of the opinion that we haven't seen the last of Martian volcanism. After all, we really don't have a complete understanding of the process of core/mantle cooling in rocky planets. And as for Marsquakes, we also have to remember that the Tharsis bulge may yet be in the active process of deformation as it settles, which can drive quake activity. And billions of tons of dry ice get deposited on, and removed from, alternate poles every Martian year, which has to have *some* impact on the overall flexing of the Martian crust.

About the only thing I would think is pretty certain about Martian crust/mantle interactions is that there seems to be no sign, whatsoever, that active plate tectonics are happening on the planet currently. Other than that, I think the door is wide open for most other processes.

-the other Doug

Could be. But my gut feeling is that it's water-laid sedimentary rock, similar (thought of course not identical) to the sedimentary rock we've seen at Meridiani.

We'll know pretty soon.

-the other Doug

It's pretty certain that Mars' core has solidified and gone cold -- Mars no longer generates a magnetic field, and if its core was still molten, current theory is that it would generate a magnetic field just like the Earth does.

However, there still may be isolated pockets of molten magma in the mantle, here and there... that's not been completely ruled out. (And the detection of methane generation at various places on Mars makes it seem a little more likely, since methane is usually only produced by volcanic activity or biological activity.)

Remember, Earth's quakes are mostly driven by tectonics. And while Mars may once have had tectonic plates, its crust spreading and subducting in various places (detection of magnetic "striping" similar to what we see along the mid-ocean ridges in Mars' southern hemisphere suggests it), since its core has gone cold, it's most likely that Mars' plates have all fused and its crust no longer floats on a liquid mantle. Therefore, there's no major source for Marsquakes.

But, I have to admit, you're right -- the seismometers on the Vikings didn't return much in the way of usable data, so we don't know for sure how active the crust might still be. And while current theory states that Mars' core can't be molten anymore, it is, after all, just current theory... current theory used to state that the Moon's core couldn't be molten, either, and recent analysis of its "wobble" as it orbits the Earth shows that not only is the Moon's core still molten, it rotates in a slightly different direction and at a slightly different speed from the Moon's crust and mantle! So, theories can always be expanded upon... *smile*...

-the other Doug

Io isn't kept mostly molten by Jupiter's gravity. That honor goes to the tides from the other three large Jovian moons, with Europa and Ganymede providing most of the "flex" that heats Io.

While there are a lot of objects in the Saturn system, there aren't any other moons nearly as large as Titan, so there aren't the massive tides that heat Io so much (and that probably also keep Europa's subsurface ocean liquid).

Titan is overall *very* cold, but cryovolcanism could be happening. So, we very well may be seeing calderas and active volcanism. It's just very *cold* volcanism.

-the other Doug

Um, yeah... if people are entitled to compensation for moral damages, the U.S. government owes me nearly a trillion dollars by now, for funding things that I morally oppose...

Doug

I'm sure someone is Russia is actually trying this -- this type of attempt to extort money over ridiculous grounds seems very in keeping with what I know of the Russian character and culture.

However, I doubt anyone in the U.S. will ever respond to such arguments. There were scores of similar attempts within the U.S. back in the 60s, with various crackpots insisting that American and Russian satellites and Moon probes were causing their spiritual beliefs great harm. They were all laughed out of court then, and I have confidence they'll be laughed out of court now.

Then again, what with all these right-wing religious fundamentalist judges that the current U.S. administration is trying to push into the system, I could possibly be wrong... for example, if a U.S. citizen brought a suit insisting that manned spaceflight is a threat to the process of the Rapture (the triumphant return of Christ and the immediate transportation to Heaven of the "chosen few"), there are judges currently nominated for Federal courts who might well rule in favor.

-the other Doug

Another thing to consider in re these beds of sedimentary rock within Gusev -- you need to think in terms of stratigraphic sequence.

First, you had the pre-impact rock beds that existed before Gusev was formed. The odds are fair to good that these rock beds were already jumbled and brecciated by earlier impacts -- Gusev lies at the northern border of what's called the ancient cratered terrain that dominates most of Mars' southern hemisphere. So the odds are good that the landforms in which Gusev was originally formed were highly brecciated, jumbled, shocked rocks already. The Gusev impact probably shocked and brecciated them some more.

Then you had a long period when it would seem that the crater left by the Gusev impact was filled with water. At least, trhere are a number of features that hint of this. During this time, water-borne deposition could have laid down layers of sedimentary rock on the floor of the crater.

Finally, there was a volcanic flooding of Gusev that created a new crater floor, made up of relatively unaltered lavas -- basalts, mostly. And from what Spirit has seen, these lavas don't seem to have been inundated by water. Yes, they show a tiny bit of alteration from a small amount of frost or upwelling groundwater. But they don't appear to have ever been covered by liquid water. Water hasn't had a big role in their history.

So, if we see uplifted beds of layered sedimentary rock, that rock was almost certainly formed *after* Gusev was formed and *before* the lavas inundated the crater. And considering how the lavas seem to embay against the hills, I would highly suspect the hills were formed well before the lavas came.

I will say that, on the side of possible tectonics, it *is* true that Gusev lies very close to the boundary between the ancient cratered terrain of the southern hemisphere and the uplifted Tharsis Bulge. But for the most part, the tectonic features that have grown out of the Tharsis development all seem to be much larger -- huge rift valleys, hundreds-of-kilometer-cracks in the surface, that sort of thing. I have a hard time picturing how these tectonic processes could uplift a very small range of hills within an existing impact crater without obviously deforming the entire crater and the surrounding craters.

-the other Doug

Your thinking is a bit Earth-centric, I'm afraid, TT. By far and away the more likely mechanism for upthrusting and tilting of bedrock layers in this area have to do with impact processes, not tectonics.

Since the Columbia Hills rise above the plains of lava that were deposited within Gusev after its formation (and likely inundation by water), they were probably formed as rims of ancient craters. Impacts will tilt flaps of bedrock all around. I'm pretty sure that's the process that tilted these slabs of bedrock.

A detailed analysis of the rock layers won't tell us a whole lot about the upthrust / tilting mechanism, anyway -- that's not what the science teams are so excited about. What's exciting is that Spirit has *finally* found an exposed face of layered sedimentary rock. The layers will tell a story of the conditions under which they were laid down, and *that* will tell us a lot about the history of Mars...

-the other Doug

Yes, of great interest...

It would appear that Cornell may need to pull and re-disseminate their DNS entries. They're somewhat broken.

-the other Doug

And now, not half an hour after the link above showed me both the April 17th and 18th updates, the 18th update has disappeared.

Methinks the problem may lie at the Cornell U. servers, if pages are being swapped in and out over such a short period of time.

-the other Doug

As far as you could tell from my experience, here, the "athena1" version of the site doesn't exist, since every single time I try to access it, allI get is the standard 404 not found error.

Better way to put it -- the "athena1" version of the site does not appear to exist via the RoadRunner servers I connect through.

Anyone else, at *all*, having this problem? Should I be phoning up RoadRunner and telling them they have a problem? Or should I be phoning up Cornell University?

And, BTW, the link in my post above to the "mubss" page at the Cornell site (sans the "1" in "athena") now shows the April 18th update as well as the April 17th "first entry" in this new run of diary entries by Squyres. So that page *is* being updated at the "athena-without-the-1" version of the site -- it's just not accessible from the home page of the "athena-without-the-1" site.

-the other Doug

Yep, the blueberries are becoming less and less a percentage of the soils here. I'm still convinced we're seeing the deposition of the erosion products from the evaporite layer. Soil analyses of these lighter-colored dunes will determine that for sure, I imagine.

I'm still thinking that this isn't "true" etched terrain, regardless of what Squyres calls it. This is deposition of lighter-colored sand in the dunes. The "true" etched terrain is south and west of Oppy -- where there are exposed ridges of evaporite sticking out from the sand dunes. Ridges that look to me like they're the remnants of the ejecta "splash" from the ancient crater cluster of which Erebus is a part.

-the other Doug

Just a process note, here -- the above URL isn't working at all for me. If I take the "1" out of "athena1" the URL works and takes me to Squyres' most recent update -- the URL that works for me is:

http://athena.cornell.edu/news/mubss/

However, if I go back to Home in the Cornell site, without the "1" in the URL, the link to the mission updates is the old link that ends with April 2004. The new update doesn't appear accessible from the home page of the Cornell site that I can get to. (Which is really odd, considering the new update is accessible with the direct link above.)

Does anyone know what's going on with the Cornell site, or why I'm not able to connect using this "new" URL with athena1 rather than athena in the address?

-the other Doug

It does bring up the possibility that one or more of those in the middle range were either conceived or born while Apollo astronauts were actually on the surface of the Moon, though... talk about a lunar influence, eh?

-the other Doug

Nothing to be ashamed of, Jeff. It's honest work. What else can you ask of someone?

I'm 49, going on 16... I'm a career technical writer / documentation specialist / training developer / what-have-you, and since a) the bursting of the dot-com bubble and the continuing economic recession here in America (especially in the IT industry), I'm working as a manager at a Pizza Hut.

For now.

As I said, there's never any shame in doing honest work.

My first memories include astronauts, Mercury capsules and Sputnik satellites. I recall watching Ranger IX coverage on live TV -- for the *very first time*, you could watch on your TV as live pictures from the Moon flashed by.

I was hooked.

1969 was my favorite year. Of my entire life. Not just because of Apollo, but also because of Mariners 6 and 7.

I want to see new horizons, new vistas. I want to see what's beyond every horizon -- and I want to see all of the different horizons that are out there.

I guess I'm just a sense-of-wonder junkie...

-the other Doug

I'm not *positive* that fluid is all that's carving these flow features.

There is an animated gif of a number of Huygens surface images run together that shows *something* flowing along some of these flow channels. (I downloaded the gif and didn't keep the link, but since it's a 5MB gif, I can't attach it here anymore... *sigh*...) I suspect the "ghosts" flowing through these channels are whisps of fog (for want of a better term) that are being drawn to the updraft being caused by the relatively superheated Huygens -- but they *do* follow the flow channels.

In a 1.5B atmosphere of exotic composition, isn't it possible that the air itself (especially Titan's hazy, aerosol-rich air) flows as much as blows along the surface, and creates surface features that look like liquid-carved features to those of us who live in a 1B atmosphere on a liquid-dominated surface?

Remember, on Earth (and even on Mars) there are dramatic microclimatological changes that occur in the last few centimeters above a planetary surface. There can be startling shifts in air temperature and pressure in surface-hugging layers of air only a few meters, or even a few centimeters, thick.

I think we could be seeing surface effects in the Huygens images that are unique to the Titanian environment and caused by a combination of occasional fluid fill and constant, slow, heavy, "moisture-laden" air flow.

-the other Doug