I know that the human eye, located on Mars, would see those greens as more greenish-gray, and the whole scene would have a little less contrast. But I can make those adjustments in my head -- and when I do, I am standing on the top of Husband Hill, taking in an absolutely breathtaking view.

Oh, yes, I am glad I've lived long enough to see this.

Thank you very, very much, dilo!

-the other Doug

Way!

-the other Doug

Oh. My. God.

I'm grateful to be alive to see this view.

-the other Doug

I wonder if it's friendly?

-the other Doug

This whole thread reminds me of the joke about the guy who was dissatisfied with his service at a restaurant, and made his complaints loud and long to everyone within earshot. The maitre'd comes out, talks to the man, replaces every dish with one done *exactly* to the customer's specifications, and generally is the compleat host, making sure that everything is now perfect.

"Is everything now satisfactory?" the maitre'd asked.

"Yeah," grumbled the guy, "except... I was happier with my complaint!"

As long as people are happier with their complaint than with having their complaints satisfied, it will be a challenging world in which to live -- especially if you have a habit of *thinking* and - even more dangerous - questioning "what everyone knows."

Please recall the words of someone who knew a little something about Mankind's striving: "...Mankind is more disposed to suffer what evils are sufferable than to right themselves by abolishing the forms to which they are accustomed." (Extra credit for those who can identify the writer and the document.) Also, note the correlation of that statement to my earlier comments about the scientific method, and having the courage to leave behind those theories that have been disproven by factual, empirical evidence and thereby "abolishing the forms" to which we have become accustomed.

It sickens me to *death* that there are people out there who refuse to believe that Mankind has realized one of its fondest dreams -- to walk the surface of another *world*. That people can be motivated to give their energies and their beliefs to *denying* such a colossal achievement -- that people would prefer to believe that it must have been faked, in some tawdry scam.

How dysfunctional do you have to be to insist that something as *wonderful* as this could never have happened, must have been a hoax, as if the very possibility of it actually having happened is some kind of *threat* to them?

And what kind of Tomorrow can we expect in a world in which a significant percentage of the people *are* that dysfunctional?

-the other Doug

Oook. Definitely.

-the other Doug

Gravity. In specific, gravity from a third (and even fourth or fifth) bodies. Around Mars, I'd guess that Jupiter generated a gravitational resonance that braked Diemos and Phobos enough to be captured. Tidal influences can then work to circularize the orbits.

I find it fascinating that, according to one current theory, Uranus and Neptune may have formed *between* Jupiter and Saturn. I can just image the gravitational resonances that must have disturbed the entire Solar System when those two giants were flung out into the outer reaches...

-the other Doug

Exactly. What you'll note here is that spiritual beliefs (i.e., beliefs that must be taken on faith, that do not stand the scrutiny of scientific investigation) are what have, historically, kept civilizations from developing what we know as the scientific method. And, indeed, there is a discontinuity between a method that requires you to discard beliefs when they are disproven, and a set of beliefs that require you to *never* require proof of them.

And while my own spiritual beliefs tend toward the pagan, I am first and foremost a scientific rationalist. Which means that my spiritual beliefs are a subset of my world-view, not the whole set.

I'm a strong believer in spirituality. But I'm a stronger believer in scientific rationalism. And, as someone who chooses to learn from history (and not just ignore it when it conflicts with my preferred world-view), it seems clear to me that when non-rational world-views (i.e., most faith-based systems) are encouraged to take over your entire world-view, you lose the ability to question beliefs that are at best incorrect and at worst devastating dead-ends when it comes to developing useful technology.

Is it any wonder why this growing popular anti-science movement, based as it is on a backlash from those who want to dismiss science because it doesn't fit their faith-based world views, seems so threatening to me? And seeing what Richard has written, I'm not the only one with serious concerns.

-the other Doug

Probably not. The Roman (and before it, the Greek) set of world-view paradigms did not allow for many avenues of scientific inquiry. Especially in the area of physics. While the Romans and the Greeks before them accomplished great things in terms of practical engineering, they developed them as outgrowths of hands-on materials experience, not from any actual understanding of how the materials are put together.

Therefore, the Romans never developed technology beyond a certain level, even though they had the time and energy and resources to do so. Without the massive shift in world-view paradigms that occurred in Europe during the late Middle Ages and into the beginning of the Renaissance, there would never have been an Industrial Revolution.

The same thing happened in China, where the very foundation of their world-view did not allow modeling of physical systems, because the Chinese believed that every system has a spiritual element that cannot be modeled. If you believe it is not possible, or not ever useful, to construct a model of a system we see in the real world, you'll never go down the path of the sciences.

So, while Christianity may have subdued some forms of art and literature, and the Roman way of looking at technology, it did not stop Roman techological development. Romans did that themselves -- their technology was as mature as they were ever going to make it prior to the Christianization of the Roman Empire.

-the other Doug

Quick update on my connectivity issue -- I've narrowed it down to an issue with my cable modem. If I completely reboot my cable modem, the Pancam web page (and a whole lot of other pages out there) load instantly, no problem. I can even get Steve Squyres' updates at either the site that begins with athena or the one that begins with athena1 -- that's been an issue for me for quite a while.

After the cable modem has been running for a couple of days, several websites stop loading again, including this Pancam site. I'm not sure if there is some hidden problem with the cable modem's built-in firewall, or if my roommate's machine (connected in via a cable router) might not be bollixing up the cable modem with his copy of AOL and its attached utility, Port Magic (which manipulates the ports on your cable router and cable modem). I'm tempted to think Port Magic is closing random ports that some websites need to use to connect.

It's easy enough to check -- I'll just remove Port Magic from my roommate's machine and see if the cable modem still gets screwed up. (I used to Beta-test for AOL, and I know for a fact that this latest AOL client will run just fine with Port Magic removed from the system.)

So, at least I know where the problem actually resides. Now to see if I can find the actual trigger...

-the other Doug

Spirit's RAT may be worn out, but it can still brush rocks, right? Why not leave a distinctive mark on "Summit Rock" with a pattern of brush marks?

Maybe something as simple as this (I hope this spaces out right):

O O
O

Sort of a "Kilroy was here" kind of mark...

-the other Doug

Now, there's an idea -- a Mars orbiter with a synthetic aperature radar, a really *huge* fat data pipe back to Earth, and a big gas tank for orbital maneuvering. Put it into a Molniya-type orbit around Mars (very high apoares, very low periares) with the high point over the MSL landing site. Do really good SAR work on the low point of the orbit and use the thing as a relay for MSL during its long climb and fall to/from its high point.

Use the really big gas tank to change its line of nodes on occasion, to change the area where the periares occurs and maximize the usefulness of the SAR. After all, you can shift the low point of such an orbit quite a bit and still keep it high in the sky over nearly half of the planet, most of the time.

Oh, and postpone MSL from 2009 to 2011, and then you have the proper telecom relay *and* good SAR capability at Mars.

-the other Doug

Problem is, they've been planning *every* day as if it will be their last since each vehicle's sol 1. Squyres himself, in his book, speaks of being very high-strung about anything that would take away a productive sol, because they only had 90 (or less!) to work with. He also speaks of the team getting more laid-back and less nervous about their babies dying anytime soon as they doubled, then tripled, then quadrupled their design lifetimes.

I wonder how hard it is to maintain that kind of emotional energy, to assume that your project (and your present Life As You Know It) is going to die soon -- keeping at that fever-pitch for month after month, caught in the tension between assuming you'll be dead tomorrow and hoping you'll survive indefinitely. I would think that would be nearly as exhausting, in the long run, as living on Mars time.

-the other Doug

Exactly -- each mission does, indeed, build upon what we learned from the last one. Without the Pioneers, we might not have designed the Voyagers to properly withstand the radiation environments at Jupiter and Saturn. Without the Voyagers, we wouldn't have had nearly as good an idea of which instruments would give us the best scientific return from Cassini. (For example, had we not done the Titan flyby during Voyager 1, we might not have included RADAR on Cassini.)

My memory of the whole Grand Tour concept is that, sometime in 1968 or 1969, I saw a proposed plan for two Grand Tour spacecraft that would require Saturn V boosters. They would take advantage of the late-70s launch windows to send both spacecraft to each of the outer planets in turn, with entry probes for the gas giants and, IIRC, a Titan hard-lander.

When NASA decided to shut down the Saturn V production line in late 1969, the people at JPL proposing the Grand Tour mission took it rather poorly, insisting it was total madness to pass up an opportunity like this. They made some enemies at other NASA centers with their vehemence. For a while, no plans for late-70's outer Solar System exploration were allowed to have the words "Grand Tour" in them -- it got that bad.

Pioneers 10 and 11 were already in the pipeline, and a follow-on mission, consisting of similar Jupiter/Saturn flybys *only*, was being developed that later became the twin Voyagers. But during the process of designing the Voyager missions, the Grand Tour aspects were played WAY down. It was as if the JPL teams were told that bringing up Grand Tour was a good way to kill the Jupiter/Saturn flybys. But, at the same time, they designed both spacecraft with enough power and maneuvering gas to handle the full Grand Tour -- with a little bit of luck.

So, at least the way I remember it, we got almost all of our Grand Tour mission by selling it as *only* a set of Jupiter/Saturn probes, and sneakily adding the Uranus and Neptuine encounters only after the spacecraft were in flight. Even though the Grand Tour was implicitly designed-for during spacecraft and mission development, it was simply not discussed in detail for fear that those who thought they had "killed that Grand Tour nonsense" wouldn't notice until it was too late...

-the other Doug

Alas, materials technology just isn't up to it yet. The only materials we've ever come up with that would be strong and flexible enough to use to build a space elevator can currently only be produced in strands measured in microns, and no one has a really good idea of how to practically put them together into larger structures.

When (if ever) the materials technology is up to it, it's a good idea, though.

-the other Doug

I wonder how much of the dust in the air at Gusev was raised locally, and how much is part of a more regional (or even global) increase in dust saturation levels. Which brings up a good question that I haven't seen discussed anywhere:

How much of the dust raised by dust devils stays entrained in the air, and how much (if any) is immediately dumped back down onto the ground? And what are the grain size ranges of the dust that stays aerosol and that which settles out soonest?

I don't know whether or not the raw images we get to work with have enough information in them to make anything like a good analysis of these questions, but it seems to me that this is one of the more useful datasets we can get out of close surface observation of dust devil activity.

-the other Doug

The only problem I have, conceptually, with the idea of dust lag deposits around vents is that a comet nucleus has an incredibly small amount of gravity. Such that the gas pressure of the sublimating ice would propel any entrained dust well away from the vent site (and likely completely off the nucleus).

I'm truly fascinated by low-gravity surface dynamics. The visual similarities between the low-G surfaces we've seen up close (Tempel 1, Eros) and moderate-G surfaces (Moon, Mars, Earth) has surprised me. I suppose that, given enough time, even very low-G surfaces end up pulling rocks and dust into familiar-looking landscapes...

-the other Doug

Maybe we're seeing a snapshot in terms of the E ring -- in other words, maybe it usually consists of mostly water ice derived from Enceladian venting, and it's been recently enriched with silicates from an impact at Tethys? As time goes on, the water ice will continue to be replenished, while the silicates might sort out?

I'm just trying to point out that we tend to observe things and assume that they're in some type of steady state -- not changing much over time. Perhaps we're seeing the E ring in a far different state than it was, say, 30 years ago, and that it'll be in a different state in another 30 years....

-the other Doug

As I understand it, Assemblee was a lone rock sitting on the ground and not a portion of the Voltaire outcrop, correct? If that's so, then it's also possible that Assemblee could be a chunk of lacustrine material that has been impact-excavated and dropped into its current location.

I imagine it would make a difference *when* the rock was tossed onto what is now its home hillside -- for example, if it was ejected from a really large crater from underneath a thick basaltic cap, it was probably a lot more shock-altered than if it was ejected out of a primary lacustrine surface (a lot longer ago) with no rock cap.

-the other Doug

I was just expressing agreement with similar statements earlier in the thread (not by me). And quite frankly, you can take the "current" out of my statement -- all politicians, to one degree or another, appeal to peoples' fears and hatreds to gain their support.

Sorry, did not mean to offend...

-the other Doug

I'm not amazed at all. People have a remarkable ability to ignore or explain away facts if those facts don't fit what they've decided is the truth. The anti-intellectual mantle helps one to do that -- you simply say to yourself: "Well, these scientists were obviously in on the scam, and since I have absolutely no clue as to how they got these results from these supposed moon rocks, I can comfortably assume that the scientists are just using their scientific double-talk to try and fool me. Well, they can't fool me! I know better! It was all a scam! Hah! See? I'm smarter than they think! How dare they try and fool me with their made-up scientific double-talk, anyway!"

You see how the thing progresses? It comes from a deep-seated sense of inferiority over living in a world that's too complicated for them to understand, and a hatred of anyone who claims to understand things they don't... It's that fear and hatred that the politicians are currently using to their own advantage.

-the other Doug

It's that "one way or another" that chromium (or many other elements) got into the rocks that's a telling point, though. And there are several ways you can look at a rock and postulate how such elements got there.

I don't have any data on the implications of this chromium content, but, for example, abundances and forms of sulfur, bromine and chlorine in rocks (both at Gusev and Meridiani) tell us a lot about the amount and type of water that once existed in and around the rocks and soil. The rocks themselves give us strong clues as to the "one way or another" that these elements got into the rocks -- if we can interpret them correctly.

-the other Doug

I think this looks like a place where we could profitably do some intensive mini-TES work. See if Home Plate and the dark hill beyond are just basalt or... something else...

-the other Doug

When I look at it in that perspective, it *really* looks to me like the west side of the Hills used to be a flat plate of bedrock (that had a big crater in it), that's been tilted up and now sticks up out of the ground at, in the Phil-O-Vision view, looks like a 70-degree angle. (So it's really only a 30-some-degree angle, at its steepest.) The break between the two peaks defines a portion of the ancient crater rim, still embedded in the uplifted, tilted rock bed.

Anyone else see that in this image?

-the other Doug

There are several sets of, for want of a better term, crater chains on Rhea, some of which appear to be hundreds of kilometers long. They are in varying states of degradation, so these chains have been forming over a fairly long time frame.

Something is controlling the orientation of those crater chains -- some seem very straight, others define gentle arcs, but they are definitely arrayed in chains.

The chains are either internally or externally controlled; those are the only two choices, right? I can see, on the conceptual level, arguments for either method.

On the internal control side, we can see that most of the icy moons of Saturn have surfaces that appear extensively cracked, twisted, or otherwise deformed. It wouldn't be a huge stretch to imagine Rhea being cracked, both internally and externally, prior to its final major resurfacing -- and that subsurface faults that still exist (and that occasionally exhibit movement under the proper gravitational triggers) could manifest on the surface as strings of huge sinkholes spaced evenly above the deep faults.

On the external side, we've also seen crater chains on some of the other moons, and of course we see the central bulge on Iapetus -- all of these attest to dynamics of ring-moon collisions that may be fairly unique to the Saturn system. With all of the ring debris in the environment, a stray ringlet arc that gets tossed out of its orbit via an unusual gravitational resonance might run across a moon, and the ringlet arc might well define a straight or an arced line as it intersects the moon's surface.

I tend to the latter theory, that in Rhea's case, the crater chains are probably where Rhea has collected up tossed-out ring arc fragments.

The craters in these chains don't look like linear ejecta from larger impacts to me, either -- they don't tend to vary a lot in size, and while there are a few somewhat larger craters to which some chains are arrayed radially, a single chain tends to be the *only* chain that's actually radial to that larger crater. If a crater chain was made up of ejecta, I would expect to see a considerable variation in the nature of the ejecta and the size/population of the secondaries as a function of distance from the primary, and that's just not what we see in these chains. So, I think we can safely eliminate the "easy answer" that the chains are simply rays of ejecta, and accept that one (or possibly both) of the more exotic options above *must* be true...

-the other Doug