Outhouse Rock was indeed the smaller rock (roughly the size of an outhouse) that had split off from House Rock. Interestingly, while Charlie Duke christened the large rock House Rock ("Well, that's your House Rock, right there"), he made it sound like they had talked about finding "rocks the suize of houses" pre-flight, but according to all of the interviews I;ve read, they hadn't -- Duke just came up with the name on the fly.

That said, I bet there are tons and tons of house-sized rocks on Mars...

-the other Doug

I have a slightly different issue to bring up, though it sort of fits in with this general topic.

Last night, The Science Channel (formerly known as Discovery Science) ran a show on its Tuesday night "space lineup" that talked about how Cassini was *scheduled* to arrive at Saturn in 2004, and in the meantime let's look at the Pluto Express probe that's currently being designed...

And then there is the "By Jupiter" documentary they run once a month or so, which is an hour-long promotion of the "upcoming" JIMO mission.

Why not just run documentaries on how VentureStar will soon replace the Space Shuttle, or even better, run some of those old ones which promise us that men will walk on the Moon sometime in our lifetimes?

In other words, there is either a really severe lack of up-to-date documentaries on space and astronomy, or the people who run The Science Channel are so ignorant of what's really happening that they think it's OK to keep repeating these dated programs, which refer to probes that never were and never will be.



-the other Doug

Yes, but... history is replete with examples of situations where the original discoverer, first publisher, etc., gets passed over and the real estate, planet, formation or effect are named after someone else. (After all, we don't call the land masses on my side of the pond North and South Columbia, or even North and South Erikland. They're named after the guy who published the first well-used *maps* of this hemisphere.)

In other words, these things have never been done fairly. Who are we to start now?

-the other Doug

Drat, I knew I should have added this in my first post:

"This is all assuming we're speaking of 'fire' in the familiar terms of rapid oxidation of flammable materials."

I think bringing chlorine into the discussion is rather like someone asking if there are waterfalls anywhere else in the solar system, since you need liquid water for them, and having someone point out the lakes, etc., on Titan. Yes, there is *fluid* in lakes on Titan, but ethane can't ever make a *water*fall...

-the other Doug

Well, yes, there are a number of different non-organic materials that will burn, given a decent percentage of oxygen in the air. Floyd's other point is still very valid, though -- the only mechanism I've ever heard of for achieving that decent percentage of oxygen in the air is via photosynthetic plants.

Now, if someone can give me a decent mechanism for getting a lot of free oxygen in the air without photosynthetic plants being present, then I'll agree that you can have open fires without life...

-the other Doug

The problem with making estimates of the total mass of the Kuiper Belt and Oort Cloud is that we only have a rather general idea of the original composition, extent and characterization of the solar nebula. We have some rather basic constraints to it, but we really don't have a lot of definitive data to determine how much mass was in the original nebula, what the distribution of that mass was throughout the nebula, how much has been ejected from the solar system over its lifetime, etc.

There are models out there, of course. Depending on which model you use, and how you set your variables, you can get any number of answers for how much mass is wandering out there past Neptune's orbit.

-the other Doug

Whereas, at age 51, I think I could really get into that interface... however, at this advanced age (well, OK, with my *knees* at this advanced age), I'd prefer a large-screen wrap-around or arm-hinge monitor that I can use while seated comfortably.

-the other Doug

I don't know about that. I think from what Squyres has said, they're more likely to enter the crater in the next three or four bays.

I'm thinking that this last drive, up and away from the rim, is a set-up for a short sprint straight east into the dark streaks. Oppy can then work south towards the rim through the major dark streak, characterizing the soils outside the streak, inside the streak, and along the boundaries.

-the other Doug

Practicing pleasing, poetic phrasing, Tom?

-the other Doug

Actually, using airbags is good for any experiments where hydrazine and other rocket exhaust end-products would contaminate the ground and make it more difficult to find what you're looking for in the soils around the lander. As it is, Phoenix data will have to be adjusted somewhat to filter out the observed effects of rocket exhaust on the soils that will be studied.

The odd part of this equation is that you want soils undisturbed by rocket exhaust for your heavier landers, while you're not nearly as concerned about the issue if you're just deploying things like seismometers and weather stations. So, in that regard, rocket landers are more appropriate for netlander-style small stations, while airbags are more suited to larger payloads. Unfortunately, the physics and engineering of the landing systems are exactly the reverse, with airbags more suited to small landers and rocket-assisted landings more suited for large, complex landers.

I think the solution is basically to make large landers which would benefit from undisturbed soils at least somewhat mobile. The problem there is that you spend an awful lot of your mass budget making your probe mobile, which means you have less mass than you'd like for experiments.

-the other Doug

No, neither MER is close to any one of the LRVs in terms of total mileage. But the two MERs combined are approaching half to two-thirds of what one LRV drove, on average.

I'm thinking in terms of the LRVs driving an average of about 25 km per mission. The longest distance traveled by an LRV was on Apollo 17, I know, and I think LRV-2 on Apollo 16 traveled the shortest distance (by a small bit). I seem to recall that Apollo 17's LRV-3 traveled about 32 km, so I believe the average per LRV should be in the 25 km range.

And the total MER mileage is, what, about 16 km at this point? If they stay active and Oppy keeps adding kilometers running circles around Victoria, the total of both MERs may equal or exceed the average single LRV driving distance.

Of course, the total time spent driving LRVs on the Moon was probably eight to ten hours over the three J missions, while it has taken three years for the MERs to get as far as they have. But that's just the nature of the beast. I'm still in awe of what the MERs can do.

-the other Doug

Sounds like a new entry in that venerable old film series: "Carry On Orbiting Mars!"



-the other Doug

Also, from what I've read, the airbag concept just doesn't scale up any further than a MER-sized payload. In fact, they were right on the edge of what an airbag system can do with the MERs.

They (our own Mars Engineer, among others -- hi, Rob!) tested the same airbags as used on MPF with MER masses, and the airbags literally came apart at the seams. Several precious kilos of mass went into beefing up the MER airbags to ensure they would work, and the conclusion of all concerned seems to be that you can't land anything much more massive on Mars than a MER using the airbag system.

-the other Doug

Actually, the yard used to be the distance between a liege lord's nose and the tip of his finger on an outstretched arm. No matter that a particular lord's lands had a different length for the yard than anyone else -- it placed his stamp on everything built during his reign.

-the other Doug

They must have looked hard for them, I think they've been tossed on the floor by the time the video starts...

-the other Doug

Doesn't Adobe Acrobat have an option to activate/de-activate links from within PDF pages? Perhaps that's your problem...

-the other Doug

As an American, I never got to see these "in person," but I saw one on a news story here. You see, when Britain went over to a decimal money system, they ran a series of public service announcements urging people to use the new decimal money.

The PSAs had a little jingle that I still recall, perhaps because of the actual way they stated some things. Specifically, while the decimal money was called decimal, the old-style money-counting system was referred to by the abbreviations for pound, shilling and pence, which for some odd (and I'm sure quite English) reason was abbreviated to "LSD." So you got:

"Decimal shops
Give decimal change,
LSD shops give...
LSD change!"

Hearing that for the first time, I figured there was no problem -- you'd have no issue getting rid of LSD change. Just invite a lot of people from San Francisco...

-the other Doug

Actually, Linda spotted what she thought was another moon peeking out from behind Io. But, as a crack member of the navigation team, she quickly realized that none of the other moons big enough to make such a large image could possibly be arrayed behind Io. It was then that she decided it had to be a feature on Io's limb itself, which led to the conclusion that it must be a volcanic plume.

-the other Doug

So, what you're really asking all of us is, does this data make Uranus look fat???



-the other Doug

p.s. -- those of us guys who have ever been married already know how to answer that question...

One other strong recollection I have of that day -- when I got home from work, I recorded all of the various angles they were telecasting of the accident. One of the feeds they ran was the now-famous view from the main tracking camera, but they were running it in very slow motion, almost stepping through the frames one at a time.

I discovered, to my chagrin and horror (and rather great interest) that if I did a fast-forward scan of the slo-mo replay of the accident, I got a slow motion at exactly the right speed to be able to see and recognize motion *within* the expanding fireball. I could literally see the motion of the orbiter separating from the stack (in a rather extreme spin around its X-axis, I believe it was clockwise if viewed from above) and, just as it began to fall back away from the stack, the crew compartment and nose start to break downward and to the side. Just thinking about it still leaves me feeling faintly sick to my stomach...



I will point out, though, that this is not the same type of thing that McAuliffe's mission was. After Challenger, Morgan applied for the program and was accepted as a full-fledged Astronaut Candidate (or AssCan, as they're called) and is a fully trained and qualified mission specialist. Yes, she will be performing some Teacher In Space projects while she's on orbit, but she's also one of the primary RMS operators on her flight, and has many other duties and responsibilities for her ISS construction mission.

So, while she's going to be a teacher in space, Morgan's flight will really have little to do with the original Teacher In Space program that recruited both her and McAuliffe 20-some years ago.

-the other Doug

Actually, if you do the "which of these things is more like another" game, you'd have to say that Jupiter's internal arrangements are closer to the Sun's than to Earth's, and the Sun's internal field dynamics change on the order of tens of years. It would also be easy for me to believe that Jupiter's insides are more dynamic and faster-moving than the Earth's, being made of far less dense gas and plasma than the molten and solid rock, nickel and iron that makes up most of the Earth.

Besides, I have this gut feeling that magnetic fields are derived from the spinning of a transition shell around a planet's (or sun's) core, not by the spinning of the core itself. As entropy progresses and a body slowly cools, the nature of that transition shell both fluctuates in well-developed periods and undergoes basic changes with time, so the periodicities and their characteristics change (slowly) as time goes on.

-the other Doug

It seems to me that since photons take so long to make their way out from the Sun's core to the photosphere, *any* variability in the Sun's output must be due to the electromagnetic conditions at the surface, where they are eventually "let out."

And we already know that the Sun's magnetic field is rather highly variable over even short periods... it takes rather less of a leap of logic than the authors of this paper seem to take to assume that long-term periodicities are driven by the same magnetic field fluctuations that drive the short-term variations.

-the other Doug

I was at work in downtown Chicago that morning. A good friend of mine called me to tell me that "the space shuttle exploded."

I worked for another ten minutes, took an early lunch, and went to a bar & grill that had a TV set, where I watched the breakup for the first several times that day. As much as I might have wanted to, I didn't order a beer. Or a shot. But I sat in chagrin and misery.

That was one of the longest lunches I've ever endured.

-the other Doug

I also think there are likely differences in the softness, bearing strength, etc., of the hills unit(s) as opposed to the plains unit. The lava plains are full of hard basalt, which erodes slowly and retains its cratering record better than the softer rocks that make up much of the hills. Remember, one of the first things we saw when we reached the hills unit was a rock that had literally rotted away from the inside, leaving only the more resistant weathering rind. That makes it look a lot like the rocks that make up the hills are *much* softer than the lava plains. (RAT experience also confirms this.)

As for crater counts -- the crater count at the Taurus-Littrow site visited by Apollo 17 was relatively low, indicating a rather young surface. Definitely younger than the Serenatatis plains. What they discovered was a surface just as old as the surrounding plains, but mixed with a significantly greater amount of glass. The glass made the regolith softer, and it retained its cratering record more poorly than surfaces which had not been mixed with as much glass. Crater counts falsely made the surface appear young because that particular part of the Moon doesn't retain its small craters as well as most other parts.

The Apollo 17 lesson is clear -- crater counts are only indicative of relative ages on surfaces which have similar capabilities to retain their cratering record. Comparing crater counts between softer and harder surfaces isn't always indicative of relative age.

Besides, it's visibly obvious that the lava plains postdate the hills. They are embayed against the hills. The view from only a dozen meters up Husband Hill gave rather stark proof of that. However, I am continually intrigued by the semi-circular "cut" in the ridge that forms Ramon Hill's crest. It looks for all the world to me like the hills were uplifted such that the surface angled up along the east side of the Columbia Hills ridge, and the circular bite out of the ridge is the nearly unrecognizable remnant of a crater rim in the pre-uplift ancient surface...

-the other Doug

Got it in one, Tom!

-the other Doug