Yeah -- insisting you're in the clear because you took images "from Google" is like a cop asking a robber where he got his loot, and the robber saying "I got it from the road." No, he didn't -- the road took him somewhere, where he then stole something.

Google takes you to websites. At many websites, there are copyrighted materials on display. You can no more just lift that copyrighted material and use it for your own purposes (with no attribution) than you can walk in a store and just take what you want without paying.

It's a good point to remember -- just because something is displayed on a website doesn't mean you're free to use it for whatever purpose. Until the copyright laws are changed, anyway.

-the other Doug

Time of your life, eh, kid?

-the other Doug

Correct me if I'm wrong, but isn't it the case that there have been absolutely zero dust devils observed at Meridiani? In any image? Or from orbit?

It's my understanding that dust devils only form in regions where the topography causes the winds to curl in on themselves -- mostly within large craters. And they leave visible tracks. None of these conditions exist at Meridiani.

Now, straight-line winds, that's another matter. There seem to be plenty of those at Meridiani.

-the other Doug

Also, that description is of the area of Burns Cliff that Oppy was able to reach -- isn't that the area of the sequence *below* the main evaporite beds?

In other words, that description applies to the Meridiani area prior to its periodic inundation by a shallow sea. The desert playa formations predate the deposition of tens of meters of evaporite.

At least, that's how I read it.

-the other Doug

Hmmm... let's see, Earthshine ought to correlate pretty well to Sunshine at Saturn's distance... but I imagine there might be a small strip around the terminator that would see Earth and not the Sun.

I must say, I'm impressed with Cassini's cameras, that they can get images only from the small amount of light reflected all the way from Earth to Saturn...



Just kidding, Phil -- I just couldn't let than one lie there. As typos go, it was one of the more entertaining.

-the other Doug

It's not just that orbiters are better (though that rather goes without saying, in many ways).

First, there is the issue of time-and-change-dependent observations. If one of your goals at Europa is finding places where the ice crust is thin enough to provide some form of access to the ocean below, you need to observe Europa over a matter of weeks and months and track the movements of the crust.

Second, there is the issue of coverage. No matter how you design your approach trajectory, you're going to be able to observe only a tiny fraction of the surface during a fast fly-by. And there will only be one side sunlit during that snapshot. So no matter how capable a fly-by probe might be, its choice of what it can view is severely limited.

Lastly, there is the politics of funding. We are *barely* to a point where we can think about getting Congress to fund a Europa Orbiter mission -- a mission that we really need, in order to answer fundamental questions and set up a possible landing mission (and, more ambitiously, a mission to explore the subsurface ocean). Because of the points I raised above, a fly-by mission is far less likely to provide those answers, no matter how much data it returns about a very small portion of Europa. And now, *in addition* to funding an orbiter for a billion or more dollars, we're going to ask them to fund an interim fly-by mission for another half a billion dollars? If we were to do that, we'd end up with either the less-useful fly-by and NO orbiter, or (more likely) just getting laughed off the Hill for trying to get them to fund *two* different missions to the same chunk of ice millions and millions of miles away -- a chunk of ice most of them think is worthless in the first place.

Is that a little better answer than a simple "orbiters are better" statement?

-the other Doug

If I recall properly, I got an e-mail from Alex Blackwell, letting me know there was a new forum that could be an alternative for those of us who were tired of the signal-to-noise ratio out on Usenet.

I think I joined in the first few days the forum was in existence. I made a few posts, then got distracted... and ran across the bookmark again some months later. I've been pretty steadily active ever since.

-the other Doug

I've seen work from professional layout artists that's far worse than what you put together, Doug. I know, templates help a lot... ... but it really did turn out looking very, very good.

I also think the piece has intrinsic value. I bet it would make a nice sidebar in some science magazines' article about the MERs in the next few months.

-the other Doug

And besides, if we can adapt to live *on* distant stars, why don't we just adapt to live on our *own* star first?



-the other Doug

The amount of detail you got is truly astounding. Great work!

My only constructive criticism is that the dark areas ought to be greenish-grayish, instead of purplish...

-the other Doug

Gee -- maybe I ought to go to night school, get a geology degree, and see if I can snag a place on the MSL geology team...

Drat, I've been having that same dream again, haven't I?



-the other Doug

This whole discussion reminds me of the net kook who insisted he had developed proof for his "c" theories about a specific manned launch disaster (that occurred just short of 20 years ago, you'll pardon me if I don't invite unwanted attention by mentioning him, or giving other specifics) by determining the elements within the fireball via spectral analysis of a VIDEOTAPE that he had of the explosion.

Yep -- he put a crude spectrometer up against his TV screen and claimed that the light recorded on the video signal contained all the original wavelengths necessary to do a proper spectral analysis of the fireball.

Funny thing is, he made a big deal out of all the phosphorus he saw in his spectra... *giggle*...

-the other Doug

After reading Squyres' "Roving Mars," I want to remind y'all that this is exactly what *almost* happened to the MERs. They had some pretty impressive technical hurdles to overcome, with an ATLO that came together on a wing and a prayer. Add just one more major technical issue to overcome, and the MERs would have been forced to stand down for a late 2004 / early 2005 launch opportunity.

Just a reminder that trouble -- even serious trouble -- encountered in ATLO doesn't necessarily mean that the mission will go badly. It just means that they're working out all the bugs at the right time, on the ground when there's still a chance of fixing them...

-the other Doug

Reminds me of the big marketing disaster Chevrolet faced when they tried to sell the Nova in Spanish-speaking countries. In Spanish, of course, "va" is a form of the verb of action, roughly translated as "go." And "no" is a rather universal form of negation. So, "no-va" in Spanish is pidgin for "doesn't go."

And, of course, then there's the marketing of Coca-Cola in China, where the sound-alike ideographs first used to represent the brand name translated literally to "bite the wax tadpole."

-the other Doug

Good one, Dan... though it would be easier (and perhaps a bit more subtle) to simply "plant" a perfect obelisk somewhere amongst the protruding rock slabs...

-the other Doug

That's what I was talking about -- that's what shatter cones are, patterns of shocking in the rock caused by the seismic energy imparted into the rocks by an impact.

I think we're seeing shock patterns, some of which look like classic shatter cones in cross-section.

-the other Doug

I'm impressed by NH's relatively small physical size. As someone who remembers the early Mariners and such, it's an interesting comparison. There's a huge amount of sensing capability packed into that thing, which is no larger than the Voyagers.

In fact, it looks to me to be perhaps smaller than the Voyagers, overall.

NH looks like a 21st-century space probe, all right!

-the other Doug

My opinion of religion, on the level of this discussion, is that whatever or however you express your spirituality, I think you do so most *usefully* when you take, as a basic truth, that your deity is a practical joker.

I think David Brin has it exactly right in his Uplift War series of novels. He populates the Universe with a myriad of intelligent species, and one which we get to know well are the Tymbrimi. They are the Universe's practical jokers. Their jokes can be downright nasty, and/or destructive. The idea behind their jokes is expressed, approximately, as "sometimes you need to have a chunk taken out of your ass to get you to where you can see what you need to see, and do what you need to do." The Tymbrimi's practical jokes, large and small, were usually designed to help their fellow beings -- but that didn't mean people didn't get hurt in the process.

So, my basic take on the deity I can see, feel and sense around me is this:

God is a Tymbrimi.

-the other Doug

Interesting. I always knew, at some level, that the image from "2001" showing all of Jupiter's moons aligned in a string with the planet itself wasn't possible...

-the other Doug

Sounds like a justification for Isaac Asimov's all-human galactic civilization, to me...

-the other Doug

It's not just that the evaporite is more extensively cracked around the periphery of (and, presumably, underneath) the "campfire" than it is elsewhere. For one thing, the "campfire" area seems to be a low spot, a small depression in the evaporite. That would tend to indicate it might be the root of an ancient, eroded crater.

However, the tops of the evaporite pebbles in the more shattered area look "rinded" exactly the same as adjacent non-shattered evaporite. It looks like the whole thing eroded down to the cracked evaporite paving and *then* was shattered further, into the spiderweb cracks and pebbling that we now see.

Speaking of the pebbling, the fragments of evaporite in the highly shattered regions are more rounded and broken up, with pieces lying together in place, than you would expect to see if the evaporite was shattered as part of an underlying layer that has since been exposed, with the crater above it having been totally eroded away.

The dark cobbly material in the middle of the "campfire" depression looks for all the world like dried mud that was left after a rainstorm washed surrounding dark dust into all the depressions. The evaporite pebbles also look as if they could have been rounded by standing water. I'm sure that's not what happened, but it really reminds you of a dried-out mudhole in the middle of a cracked desert floor.

One thought just occurred to me in re the campfire, and in specific in re the spiderweb cracks around Phil's "bullet hole." We're on the rim of Erebus, here -- the remnants of the rim of a large impact crater (nearly as big around as Victoria). Could these small circular features possibly be remnants of shatter cones that were formed in the rim structure as it was heaved out of the ground during impact? If you had shatter cones developing near the lower boundary of the evaporite layer, could that form instrusions of a darker underlying layer into the evaporite through the centers of the shatter cones? That would explain the bullet-hole appearance of the one feature, as well as some of the "ponding" of dark, cobbly material...

In any event, the piles of dark, cobbly rocks and dust seem to be related to intersections of thick cracks in the evaporite, or are in the center of more-than-normally-cracked areas of the paving (which also tend to be depressions). All of that can't be a coincidence. Whether the dark cobbly material was eroded out of the layer that used to overly the evaporite paving, or whether it was dropped onto the paving after it reached its current state, or whether it's been extruded from below the paving through the cracks -- the highly cracked areas and the cobbly piles are obviously intimately related.

-the other Doug

Still can't see all the way into the Inner Basin, though. It's beginning to look intriguingly dark as the land slips behind the hill, though.

Again, this is one of the very few places at Gusev that looks as dark from the ground as it does from orbit...

-the other Doug

The "ridgy" feature becomes clear when you look at Phil's cartographic-purposed image. There is a large, very degraded crater (or, rather, a basin) located right in that area. The ridge-like structure (visible more as an albedo difference farther into Umbriel's disk) is a basin ring.

-the other Doug

This episode shows Sagan speaking to a sixth-grade science class in his old classroom -- since Cosmos was made about 25 years ago, all of those little kids are now in their late 30s.

I wonder if any of them remember the day that Carl Sagan came into their classroom and handed out glossy pictures taken by the Voyagers?

-the other Doug

Yep -- it's a rubble pile, all right. That much seems incredibly obvious. It's good to see that such things can, at least some of the time, be so visually apparent that all we'll really need is a good, close look at an object to tell if it's definitely a rubble pile.

It's also pretty obvious that there are two big, potato-shaped rubble piles in this complex, attached via a partially-buied, irregularly-shaped rubble pile. Some (but not all) of the major depressions in this assemblage are filled with fines deep enough to cover larger rocks and boulders, while more fine material provides inter-boulder surfacing within the obvious rubble piles.

I would have to think that the three visible major rubble piles were already rubble piles before this particular assemblage came together. So, as I've said, I'm pretty certain that the current Itokawa is the accretion of three rubble piles. The fines probably accumulated where they are fairly shortly (in planetary development terms) after the most recent accretion event, and the whole thing is in equilibrium -- until something else whacks it or subjects it to strong tidal stresses.

-the other Doug