Cugel, we're talking about artificial *intelligence*... that last word has very little to do with politicians.

-the other Doug

Tom, yours is an interesting theory (trying to determine the vector of the impactor), and I wouldn't discount it at this point. However, I will say that asymmetric ejecta blankets are more often caused by variations in the target rock beds than they are by the impactor's vector.

It really depends on how fast the impactor is going. Some secondaries are higher-velocity than others (and involve greater impactor masses), and above a certain velocity and/or kinetic energy (i.e., mass of the impactor times velocity), even a very depressed vector will result in a perfectly round crater and a fairly evenly distributed ejecta blanket.

Pre-existing target topography and composition usually controls ejecta asymmetry more than vector, I believe... but, on Mars, we have seen a greater population of grazing impacts than we do on, say, the Moon. What the mechanism for that is, I couldn't tell you.

-the other Doug

I've got a 2.8 GHz PentIV system (HP Media Center model, very similar to their Pavilion), recently upgraded to 1 GB RAM, also recently upgraded to a 17" flat panel monitor. Amazing, how much prices have come down -- the additional 512 MB of RAM only cost $50, and the monitor was only $230.

It came with a 160 GB IDE internal drive, a CD drive and a CD/DVD burner drive. I've since added an external IDE drive, also 160 GB. (My roommate is a hard-core trainfan, and I'm a trainfan too, though a somewhat less passionate one than he-- I have about 250 GB devoted to Microsoft Train Simulator, at the moment.)

Of course, it has the standard USB ports, plus a bunch of slots for memory sticks and cards from digital cameras and such that I actually don't have much use for... and it has a TV receiver card in it that I also have no real use for at the moment (since I have a perfectly fine DVR and digital cable receiver from my local cable company). But I got the system for free from a friend a couple of years ago, so I was happy to get it, whether or not I had immediate use for all of the bells and whistles. (He had gotten it from a friend of his who had screwed up Windows real bad, and gave it to me to see if I could reload the software. I could.)

Interestingly, it runs a variant of Windows XP called Windows XP Media Center Edition. It's pretty much identical to regular XP, as near as I can tell -- I believe it just has some additional tools it uses with the TV receiver.

It has a nice 2:1 amplified sound system, complete with subwoofer, as well. I'll tell you, when I drive a big ol' steam train through the tunnels on Donner Pass, the neighbors can all hear it! (Better yet, I bet they can feel it in their teeth... *grin*...)

-the other Doug

Yes, Bob -- so you see my point about thinking that Beagle Crater and the contact between the etched terrain and the basal unit around Victoria deserves 15 or 20 sols of close observation.

And I say liquifaction because that's a mechanism that has been proposed for the classic martian splash-pattern ejecta blankets. If you look at these blankets, the splash pattern is always relatively smooth, with little in the way of ejecta boulders or other materials evident on its surface. However, just outside of the splash pattern, you see the classic forms of an ejecta blanket, including block populations and deposition of melts and fines.

The question was, how do you erase the signs of the falling ejecta from the splash patterns? The answer was that the splash patterns were in a state of liquifaction, into which immediate-striking debris *sinks*. The whole thing shivers through the shock reverberations, erasing the immediate ejecta patterns, leaving a well-shaken plateau. That, yes, has brought to the surface low-density materials from below.

This does fit well with what we see at Victoria -- note that in the high-quality MOC images of Beagle and its surroundings (always available for viewing in the Route Map thread), there are a good dozen small craters in the near vicinity of Beagle -- all of them in the etched terrain portion. Not one of them appears in the apron itself, as far as I can see. So, like other splash-pattern craters, you can see evidence of Victoria's classical ejecta blanket, *just* outside of the basal apron.

I do hope they spend at least a few sols looking over this area...

-the other Doug

Me, either, Bob. Now, pardon me, I'm having HAM for dinner.

-the other Doug

Doug, I think your schedule sounds perfect. It will get a decent baseline of everything we can eventually pull out of the site, and give the guys in the back rooms a lot of data to chew over while the operators move on towards Victoria. And maybe gives us an idea of what else we might want to look for in any re-visiting of the boundary of Victoria's splash-pattern ejecta blanket.

The only pacing item I can see would be power -- are we still in good enough shape on the power curve with Oppy to be able to withstand the additional time sitting on flat surfaces, not perched on a north-facing inner slope of Victoria?

-the other Doug

I think the apron material will look a lot like the material out near the original landing site, with a pretty thick substrate of blueberries mixed with basaltic sand forming the ground.

I also think this is the case because of the splash-pattern ejecta blanket around Victoria. The surface rock mobilized via liquifaction (as you sometimes see during earthquakes here on Terra-Sometimes-Firma) and rippled away from the crater, leaving a less blocky, smoother-topped, shocked apron chock full of semi-jumbled evaporite. Which eroded down to a blueberry pavement, exactly the same as happened with the evaporite out on the plains.

I don't know why there is less ripple formation in this area, but the ripples seem to almost completely vanish as we approach the rim of Victoria. There is some significant rippling going on near the borders of the splash blanket, but it doesn't extend very far in from the outer border.

-the other Doug

Oh, gee -- that sounds like a really bad come-on line: "Hey, baby, wanna come back to my place and watch me operate my Mars arm???"



-the other Doug

Also (since you revived this thread, Phil), does anyone know if the impact sites of the two penetrators have ever been imaged?

This is probably more of a question for Phil Stooke, but -- do we even know generally where to point MRO to look for the DS2 impact points?

-the other Doug

I downloaded it overnight last night (I usually get download rates between 300 and 600 KB/sec.; this thing averaged 6 KB/sec.) and just got around to looking at it.

I guess I could have wished for a little more finesse in the audio track cutting -- maybe fewer individual song snippets that lasted a little longer. But generally, there was a good "feel" between the images and the soundtrack.

And the final sequence was quite well done.

-the other Doug

I looked around and found an image that showed the entire route from Eagle to Victoria (though it was a proposed route at the time). From that image, it appeared that Beagle is roughly the same size as Vostok, perhaps a little bit smaller.

It's obviously a lot younger, though. This looks like the first really fresh crater we've seen. It should give us a better idea of the types of rock it threw to the surface, since they haven't all crumbled to dust like they did at Vostok and nearly ever other small impact feature we've seen.

-the other Doug

You know, guys -- I think Oppy might have a little more work to do at Beagle and its immediate surroundings than y'all think.

Beagle sits at the transition to the *only* uniquely-Martian splash-pattern ejecta field around a good-sized impact crater that *any* Earth probe has ever visited. The current thinking is very, very strong that such splash-pattern ejecta blankets are due to the target surface being relatively rich in volatiles (specifically, water and/or ice).

I would think that observations along this very well-defined contact (at least in the MOC images) will be able to go far in confirming or disputing those theories. Especially considering that we have a Godsend, a nice, relatively fresh impact drill-hole right through the contact boundary.

That would be a very, very important piece of work with which to crown the MER missions, I think...

-the other Doug

Ummm... yes and no. The LOK was one of a family of spacecraft, most designed to be manned (if not all flown manned), which all shared a lot of hardware. But there were very specific differences, especially between the LOK and the various Earth-orbital versions (including modern Soyuz and Progress craft).

The LOK had a rather smaller "orbital compartment" than the Earth-orbital Soyuz, built to serve mostly as an airlock for the mission commander to get to and from the LK "lunar cabin" before and after his descent to the lunar surface. Its docking system (Kontakt) was an entirely different system. While neither the early Soyuz nor the Kontakt docking systems allowed intravehicular transfer via pressurized tunnel, the Kontakt system was much more forgiving of error and could deal with a lot of docking attitudes and velocities. (I believe it was tested on unmanned test flights of the LOK and LK in LEO in the late '60s.)

The LOK's descent module was also a little different, mostly due to a beefed-up heatshield. And, IIRC, the LOK's service module was a little longer than the standard orbital Soyuz, to make room for somewhat larger propellant tanks.

Also -- the modern Soyuz is an evolved spacecraft that bears the mark of a number of different redesigns over the past 40 years. The LOK is about as close to the modern Soyuz spacecraft as was Soyuz 4, for example. The configurations were virtually identical from the outside, but there have been a lot of really substantial changes "under the hood" that make the modern spacecraft quite a bit different from those late-60s versions (the replacement of many mechanical sequencers with electronic digital systems, for example).

-the other Doug

I don't have detailed numbers for you, but my gut feeling is that the proximity of the Sun is such, aphelion or perihelion, that you'd run into a similar harshness of environment (and need about the same level of protection) either way.

After all, what difference does it make if the heat outside is just about enough to melt lead, or just more than enough to melt lead? Well, except for maybe needing lead-pond floats on your spacecraft... though I will note that there is no evidence of liquid-ponding of *any* materials in the Mariner 10 images.

-the other Doug

And where do Lunar Orbiter and the Apollo Panoramic Camera fall into this mix? I believe the best LO imagery was in the range of 50cm per pixel, and the best Pan Camera imagery just a little bit better than that...

Of course, the Pan Camera was built by Itek to basically the same specs they used for the DoD's Keyhole spy satellites. As I recall, they had to worsen the optics a bit for the Pan Camera in order to conceal the full resolution potential of the spy sats.

-the other Doug

You know, with all of the, um, verbal talents of the people who frequent this forum, I'm mightily surprised we haven't seen anyone write new verses to the old song "Marching to Pretoria," supporting the altered title "Driving to Victoria."

The chorus could run something like:

"Oh, we are driving
To Victoria!
Victoria!
Victoria!
Yes, we are driving
To Victoria!
When we arrive,
Let's not
Fall in!"

-the other Doug

Ah, good -- we in the States will likely be seeing it, re-edited and with an American narrator substituted for the original Brit, run under another name on the Discovery Science Channel in about six months... *sigh*...

-the other Doug

Ummmm.... No. I'll be good. I shan't say a word...

-the other Doug

I've also heard (and seen!) hail described as pea-sized. I'd be willing to bet that this is the size I've seen most frequently, of all the hail I've ever seen falling...

-the other Doug

Don, were all of the Zenit series modified Vostoks? (You can tell it's modified -- the service module is stretched a little less than a meter from the Vostok configuration, extended by a cylindrical shell right in the middle.)

-the other Doug

You forgot a very important one, though I admit it's outdated and no longer in use. But, from the mid-60s to just a few years ago, any feature on a moon or planet that's in a range of 200 to 300 meters across was referred to as "about the size of the Astrodome."

I think it was only with the demise of the actual Astrodome structure that NASA PAO pulled that particular chimera from their playbooks...

-the other Doug

The problem, Jeff, is that the human race is already stretching the planet's agricultural potential to the limits in order to feed everyone. The biggest threat of global warming is the shrinking of total arable land to a point where we cannot produce enough food to feed everyone.

This can happen in one of two ways -- either desertification of arable land and flooding of coastal farms and fields due to rising sea levels and shifting climate patterns, or the freeze-over of arable land due to an ice age triggered by lowered salinity levels in the deep ocean convection system.

If either happens (or if both happen, one after the other), a significant percentage of the human population will starve to death. And don't for one minute think that the nation-states of Earth are above waging war to claim someone else's arable land...

-the other Doug

I enjoyed seeing your work in the latest edition of The Planetary Society's journal, Stu! Good work!

-the other Doug

You realize that by meeting two different criteria -- assuming a spherical shape due to self-gravitation and orbiting around the Sun but not orbiting another body -- you qualify under Alan Stern's definition of a planet.

I'm looking forward to seeing Steve Albers' map of planet Lakdawalla... assuming he can put together a shape model onto which he can project topographic and albedo features.



Once again, good luck and happy life, Emily!

-the other Doug

It's getting so deep in chocolate (and chewy nougat!) in here that I need something to scoop with... anybody got a Big Dipper?



-the other Doug