Printable Version of Topic

Posted by: Redstone Nov 30 2005, 04:35 AM

The Chair's report from the November meeting of the Mars Exploration Program Analysis Group is now online at http://mepag.jpl.nasa.gov/meeting/nov-05/index.html.

Here are some features on their draft exploration plan after MSL in 2009.

• 2011/2013 Scout and Mars Science Orbiter with telecommunications capability
• 2016 Mid-rovers or Astrobiology Field Laboratory
• 2018 Scout
• 2020 Planetary Evolution and Meteorology Network
• 2022 MSR Orbiter with Telecom
• 2024 Mobile MSR

I'm not sure how fixed this is, or how much it dovetails with NASA HQ's plans, (pretty close, I'd guess) but it gives us something to chew on until Bruce's Astronomy article comes out.

Note that the 2011 window is now shared with a new orbiter with "telecom capability" This sounds like the return of MTO, with science instruments added. Any ideas what instruments are at the top of the wish list for such an orbiter? If it launched in 2011, it could still play a big part in the MSL mission and be ready for the next rover in 2016. Remember by 2011 MRO will be six years old.

The Astrobio lab is an MSL scale rover, while the "Mid-rover" is intermediate between MER and MSL.

Mars Sample Return has been pushed out to 2022/24. This seems a pessimistic "who knows?" timeframe to me. A manned mission could be on the way by 2030, if the Vision for Space Exploration pans out. (A BIG "if", I know.) Sample return will have to be completed before humans go, I would imagine.

Posted by: MahFL Nov 30 2005, 01:20 PM

From the Nov 21 2005 MEPAG Chair's Report...




"The next MEPAG Meeting is tentatively planned for April 2005 and will take place in the Pasdena, CA, area. Specific dates are being explored."

Maybe they have a secret time machine ?

Posted by: BruceMoomaw Dec 1 2005, 05:12 AM

Aw. You gave away the ending...

OK, let me squeal a bit more. That "clue" I mentioned yesterday as to how the Mars program has been revised is simply that, with the 2009 Mars Telecom Orbiter cancelled, Mars Reconaissance Orbiter's lifetime as a com relay for landers will wear out at some point -- so they need another combined science/relay orbiter. If MRO succeeds, the second Scout will go in 2011 and the new orbiter in 2013; if MRO fails, an MRO replacement will fly in 2011 and the Scout in 2013. (For just this reason, the Announcement of Opportunity for the new Scout won't be released until next March -- by which time we should know whether MRO has made it into Mars orbit and is aerobraking properly.) While they've now added a direct-to-Earth com link to the 2009 MSL rover, I also wonder whether the real reaction to an MRO failure might be to fly the MRO replacement in 2009 and delay MSL until 2011. Hopefully that won't happen, since MRO up to now is working virtually flawlessly -- the only trouble has been getting all the kinks out of the new high-speed ground data link from the DSN antennas to JPL.

As for what the scientific subject of that new orbiter is likely to be, the exact nature of the 2016 mission (there are at least three candidates, and I suspect four), and the reasons for the latest delay in the sample-return mission -- well, children, I continue to hold those cards close for now. (If I keep blabbing, I won't have anything left to reveal in the damn article.)

Posted by: mars loon Dec 3 2005, 03:26 PM

Bruce, Its OK to keep blabbing. We wont tell anyone !!!

Otherwise its great to see there is finally a follow-on plan. Although it is insufficiently ambitious due to funding constraints

My opinion is definately go for MSL in 2009, NO DELAY. And a second in 2011. And some replacement for MTO capability is clearly required soon.

Posted by: BruceMoomaw Dec 3 2005, 11:45 PM

They haven't got the money for that -- the previous plans to keep steadily raising the MEP's funding are now gone with the wind. It will rise to about $600 million per year in 2007, and then level off at that point -- and they've had to cut a total of $210 million out of the funding for the last two years AFTER Congress had approved it.

Posted by: gndonald Dec 23 2005, 01:50 PM

I'm immediately interested in this one, since it looks like a revival of the MESUR concept, namely landing several landers on the surface at the same time, rather than simply one or two.

Here's hoping they manage to pull it off.

Posted by: BruceMoomaw Dec 23 2005, 09:11 PM

That's exactly what it is -- in fact, MEPAG's increasingly shrill demands for a Mars network mission are largely what motivated NASA to stick it into the program. The Network's central purpose would be to make seismic and weather measurements, although technological improvements may allow the addition of other experiments.

In this connection, see two of the new AGU abstracts. http://www.agu.org/cgi-bin/SFgate/SFgate?&listenv=table&multiple=1&range=1&directget=1&application=fm05&database=%2Fdata%2Fepubs%2Fwais%2Findexes%2Ffm05%2Ffm05&maxhits=200&="P51C-0934" briefly describes JPL's new design work on such a small network lander. http://www.agu.org/cgi-bin/SFgate/SFgate?&listenv=table&multiple=1&range=1&directget=1&application=fm05&database=%2Fdata%2Fepubs%2Fwais%2Findexes%2Ffm05%2Ffm05&maxhits=200&="P41A-0919" describes the "GEP" package which the ESA plans to add to ExoMars (and, hopefully, land later elsewhere on Mars with various techniques). Its instrumentation sounds like an exact repeat of Netlander's, except that the camera is replaced by a heat flow probe (which I presume would be implanted on the ExoMars mission by the rover's drill).

Posted by: JRehling Dec 24 2005, 01:07 AM

Has anyone ever waited for a new version of some computer/electronics product to come out, and ended up delaying indefinitely, ever waiting for a better version? I'm starting to get that feeling with Mars Sample Return. Earlier missions establish better and better assessments of where the first return(s) should come from, but this process could continue forever. What is the criterion for deciding that we know enough to validate spending the coin on MSR?

At some point, we'll have flown just about every surface-probing instrument there is to fly. With the exception of arbitrary varieties of radar satellites, that end seems within reach. All told, I think one of the biggest coins waiting to drop in Mars exploration is going to be the *analysis* of THEMIS data. When we have a good global map in THEMIS's spectral and thermal-inertia capabilities, there's going to be a lag in interpreting that massive database.

I'd like to see something along the lines of a return craft in Mars orbit that awaits surface samples that come up and rendezvous with it from multiple surface locations. A big expenditure is going to be moving the spacecraft mass from Mars orbit to Earth entry -- at the risk of a few major failure points, it would be nice thing to get multiple samples back for the least cost.

Posted by: nprev Dec 24 2005, 01:38 AM

I wonder if some of the recent MSR recalcitrance is at least partially due to the Genesis hard landing. There might be a little more optimism if Stardust makes it down okay, but nevertheless MSR will still be a much more challenging engineering proposition...

Posted by: nprev Dec 24 2005, 01:44 AM

...plus, there's the whole planetary back-contamination issue to consider also in light of the Genesis landing problems. I personally don't think that's a significant risk--I'd be delighted just to see MSR make it home, period, and far more worried about contaminating pristine material with terrestrial organics--but I'm sure some persons or groups might get a bit spun up at the prospect...

Posted by: mike Dec 24 2005, 07:48 AM

We've been hit by Martian debris for billions of years. Any Martian bug has already worked its magic on us. Any Martian sample return mission sounds good to me. Also, Frylock will rock you like a cop.

Posted by: BruceMoomaw Dec 24 2005, 08:22 AM

Not according to Benton Clark, who took a thorough look at this issue years ago. If new types of Martian germs are hitting Earth, they're almost certainly doing so at intervals of tens of thousands of years (or much longer), and we have no way of knowing what they did to living things on Earth at the time. (The Spanish flu would have left no detectable fossil trace for future paleontologists to interpret.) The risk is indeed tiny, but it is NOT nonexistent.

Posted by: nprev Dec 24 2005, 10:25 AM

...you got THAT right, yo! But Meatwad get the honeys, G...

Still, I see Bruce's point as well. The best (and unfortunately most expensive) way to do MSR is therefore probably to apply the same degree of reliability engineering to the design of the Earth return process as would be used for a manned mission.

Heck, maybe the Mars orbit rendezvous/Earth return vehicle should just be a modified CEV; this would provide an excellent operational test of that system without risk of crew lives, plus maybe let MSR tap the hopefully deep pockets of the manned program to pay the tab for this particular UMSF...

Posted by: edstrick Dec 24 2005, 01:14 PM

Jrehling: "Has anyone ever waited for a new version of some computer/electronics product to come out, and ended up delaying indefinitely, ever waiting for a better version? I'm starting to get that feeling with Mars Sample Return......"

Fusion power is always 50 years in the future.

Posted by: lyford Dec 24 2005, 05:54 PM

I almost hate to say it, but I am happy to wait. We don't know nearly enough to decide what piece of Mars to bring back - and you have to plan your trip before you can start worrying about where to "buy the souvenirs". I would rather have good data from several areas of the surface and just under; a knowledge of Mars as a geological system. We should have a better understanding of Mars' hydrologic history and the forces that controlled rock deposition before we spend the bajillions of dollars and who knows how much political karma to plan a sample return. A mission like that would almost certainly be a one off - especially if the results are negative or inconclusive for present or past life. Like Apollo, I can't see the public rallying to pay for a second mission just so "those scientists" can fill in the decimal places.

I believe we are in the beginnings of a golden age of remote sensing planetary science - so far we have a data set of 1 when it comes to a living planet with liquid water. We really need to expand our knowledge of the history of the solar system and how planets form - one could argue that Titan and Europa missions are just as important then for the Life Question.

And don't get me started on a manned mission - talk about cross contamination!

And as for fusion, I am still waiting for my http://www.moller.com/skycar/, thank you.

Posted by: ermar Dec 24 2005, 07:36 PM

Posted by: mike Dec 24 2005, 09:15 PM

So we get a few new antibodies.

Posted by: BruceMoomaw Dec 24 2005, 09:49 PM

I'm sure the victims of the Spanish flu would be delighted to be remembered that way. Act your age.

Posted by: mike Dec 24 2005, 11:20 PM

We're all going to kill ourselves anyway, Bruce. Why does it matter?

Personally, I believe that which does not kill us can only make us stronger. No one lives forever, Mr. Moomaw.

Posted by: tty Dec 25 2005, 04:16 PM

Flying cars have been built on quite a number of occasions, it's not that difficult engineering-wise. Unfortunately since the design requirements for a a car and an aircraft are rather different the result is a not-very-good car combined with a not-very-good aircraft at a price that is higher than for a good aircraft plus a good car.

tty

Posted by: tty Dec 25 2005, 04:30 PM

Martian germs hitting Earth every 100,000 year means it would have happened rather more than 30,000 times since the beginning of life on Earth. I agree with mike - if something really bad is waiting up there it has already happened.

Incidentally a really bad epidemic during at least the last 50,000 years or so would be detectable in the human genome as a "bottleneck". Such are known in other animals, e. g. the cheetah which is known to have passed through a extremely narrow bottleneck (maybe <10 individuals) some 10,000 years back.

tty

Posted by: JRehling Dec 25 2005, 04:44 PM

Obliging back contamination should be seen in terms of a payoff matrix where one possible outcome (with very low probability) is the extinction of the human race. That adds negative infinity to the weighted sum. It's going to be tough to find a positive infinity benefit of Mars samples that would cancel that out.

Posted by: dvandorn Dec 25 2005, 07:30 PM

Two comments:

Emily -- you're spot-on! One of my favorite lines is "How can it be the 21st century? The cars still have wheels!" The problem with flying cars is that, as far as anyone has been able to manage, a flying car requires a *pilot*, not a driver. It would be tremendously more difficult to train everyone to fly than it is to drive. And look at the accident and fatality rates among drivers -- that would increase almost exponentially if you tried to make billions of drivers into billions of pilots.

In re Martian micro-organisms -- for a virus or bacteria to infect a given host, it has to have mechanisms that directly interact with the host's physiology. Virii, in specific, must be able to alter the host's DNA to replicate the virii. I find it *very* hard to believe that life forms which evolved entirely separately would be able to infect terrestrial organisms. However, alien organisms *could* simply try and live within a terrestrial host and produce toxins (which are not the same thing as infectious agents) which would sicken their hosts. So, while there is a generally miniscule risk that alien micro-organisms could infect terrestrial life, there is a larger risk that they could produce toxins that could endanger terrestrial life.

-the other Doug

Posted by: nprev Dec 25 2005, 10:11 PM

Good points, otherDoug (may I call you that?)

As long as we're tossing this subject around, I also can't help but worry a bit about one part of the old Andromeda Strain scenario: "...a fabulously rich growth medium..."

If there are Martian organisms that survive on the surface and resemble terrestrial life in a biochemical sense even approximately (that is, they find carbon compounds & water tasty), I can't see any reason that they wouldn't thrive--and I use that word as a vast understatement--almost anywhere on Earth.

As Doug pointed out, they would be unlikely to attack us directly...but I can imagine a variation of the "grey goo" boogieman from nanotechnology...red goo?

Posted by: ljk4-1 Dec 25 2005, 11:09 PM

Wouldn't the biochemistry of a truly alien life form be so different from us that there could be no interaction, good or bad?

Plus this is why we don't have to worry about aliens wanting to have us for dinner, literally. Our biochemistries would be poison to them - and since they evolved on another world, they would not be designed to want us for a snack.

Posted by: BruceMoomaw Dec 25 2005, 11:43 PM

"We're all going to kill ourselves anyway, Bruce. Why does it matter? Personally, I believe that which does not kill us can only make us stronger. No one lives forever, Mr. Moomaw."

Well, in that case, Mike, let's all inoculate ourselves with bubonic plague (as Joanna Russ suggested in a story once). Personally, I would prefer not to unnecessarily ACCELERATE the date at which we do ourselves in, thank you -- or unnecessarily increase the amount of harm we do to ourselves before then. To repeat: the risk is small, but it is NOT zero -- and so it behooves us to spend a fair amount on eliminating it. Benton Clark is pushing the idea of greatly reducing quarantine costs by exposing the sample, during its long return to Earth, with gamma rays from a source onboard the spacecraft. Tests show that this would kill virtually any conceivable organism stone dead, WITHOUT seriously damaging our ability to identify the biochemicals in them (to say nothing of their visible cellular structures) -- and its effect on inorganic science studies is also very small. If, and only if, we find evidence of current Martian life in such sterilized samples would we then have to go to the trouble of building a very expensive Earth quarantine facility so that we could start bringing 'em back alive for more study.

Dvandorn's remark about toxins is spot-on, and in fact was mentioned by NASA's scientists in an issue of The Planetary Report about a decade ago. Martian viruses, being super-specialized parasites, are tremendously less likely to be dangerous to Earth organisms than Martian bacteria would be. Once again, the risk is tiny, but it's there -- consider the delights of botulism and tetanus toxins, both produced entirely as accidental by-products of the metabolism of (anaerobic) Clostridium bacteria that gain no advantage at all from accidentally killing anything else. And -- if I may dip into SF again -- see Poul Anderson's "A Plague of Masters", in which a world's native bacteria destroy the acetylcholine in the bodies of Earth animals, condemning any colonist on the planet to a spectacularly agonizing death unless he receives regular doses of counter-medicines (which end up being manufactured by an iron-hard totalitarian government, although that's irrelevant here).

Once again, why run unnecessary risks?

Posted by: BruceMoomaw Dec 25 2005, 11:46 PM

To TTY: it depends on your definition of "really bad". To repeat, there's no way that paleontological evidence -- including the evidence of our genetic heritage -- would reveal whether something as bad as the Spanish Flu got unleashed on Earth by arriving Martian germs, even if their arrival was just a few thousand years ago. Now, if it was something that almost wiped out the species completely (as happened to the cheetahs), it would be a different matter -- but I take it that we would prefer to draw the line a little short of that standard.

Posted by: ljk4-1 Dec 26 2005, 06:41 AM

Not that this would have been much comfort to those who lived through it back then, but while the Black Plague did wipe out half the population of Europe, in an age when microorganisms and antibiotics were unknown (everybody was pro-ID in the 1340s), the continent not only recovered but the event actually accelerated the society towards the Renaissance.

http://dir.yahoo.com/Regional/Regions/Europe/Arts_and_Humanities/Humanities/History/By_Time_Period/Renaissance/Black_Death/

What this says to me is that the human race is far more resilient than we sometimes give it credit for. Perhaps all life that has lasted for billions of years is the same way everywhere.

Posted by: BruceMoomaw Dec 26 2005, 09:26 AM

Hardly an adequate argument for letting plagues get loose.

Posted by: nprev Dec 26 2005, 10:21 AM

I cringe a bit at the thought of executing MSSR and not having living specimens of Martian life to examine (if they are present), but I am inclined to agree with Mr. Clark's rationale on both levels. Question, though: What kind of intense gamma source is envisioned? I can see the antinuke crowd raising quite a stink about flying something intentionally designed to kill living organisms, if you know what I mean... ...still remember all that noise over Cassini.

Posted by: ljk4-1 Dec 26 2005, 06:06 PM

Certainly not. But Nature does seem to have a way of taking care of itself when one species gets a bit too populous (who said Gaia? Did I say Gaia? Certainly not).

Our intelligence, science knowledge, and technology may be the first time in history this natural cycle might be circumvented by an Earth species. And we do have an entire Universe to move to this time.

Posted by: JRehling Dec 26 2005, 11:05 PM

That's a hypothesis; it's not a fact.

It's also possible that an alien organism would pose a hazard to us that only killed us indirectly, even if we were "poison" to them. For example, they might create an opaque coating on the ocean, causing oxygen levels to plummet.

Posted by: nprev Dec 26 2005, 11:48 PM

That's what I was talking about earlier...the 'red goo' scenario. Anything that could eke out a living on the harsh surface of Mars might go wild in Earth's extraordinarily benign environment, and to me this is the primary risk that should be considered for the whole back-contamination issue.

However...there's one possible out from this dire risk. Any conceivable Martian bugs would undoubtedly be anerobic, so the abundant free oxygen in our atmosphere would almost certainly kill 'em quite effectively.

Posted by: mike Dec 27 2005, 05:15 PM

Some people are optimists and some people are pessimists.

Posted by: BruceMoomaw Dec 27 2005, 10:29 PM

Yep, and the pessimists usually live longer.

Posted by: dvandorn Dec 28 2005, 11:53 AM

No, they don't, Bruce -- it just seems longer.



-the other Doug

Posted by: tty Dec 28 2005, 07:19 PM

Use a small X-ray tube, there will be plenty of time during transit and not even the antinuke crowd can get very excited about that.

Bruce: I agree that there is no way to detect an epidemic of the spanish flu class in the distant past. The spanish flu killed possibly 2-3 % of the Earths population at the time. Epidemics of that order have occurred very many times in the past, probably nearly every generation.

Incidentally there is a quite serious theory that Earths climate is affected by really large epidemics. It goes like this: during the medieval warm period population grows both in Europe and China, farming expands, forests disappear and CO2 goes up, as shown by Greenland ice cores (as are the changes mentioned below). Then plague (and war) hits both China and Europe in the mid 1300's, populations plunge, land goes out of cultivation, forests grow and CO2 goes down. Both temperatures and population reach bottom around 1450 and then start climbing again. Then Europeans reach America and something like 90 % of the native population is killed off by the newly introduced diseases. Both CO2 and temperatures turn sharply downwards after 1550 and don't reach bottom until 1700 as much of two continents turns into forest again. By that time native american populations have bottomed out and large-scale european colonization has started, forests are chopped down and both populations, CO2 and temperatures turn upwards....

tty

Posted by: ljk4-1 Jan 3 2006, 02:57 AM

Didn't you see The War of the Worlds? They wouldn't have a chance against Tom Cruise! Then again, who would?

Posted by: nprev Jan 3 2006, 05:52 AM

Apparently then, we're only in real trouble if the Martians manage to retain Nicole Kidman's lawyers and subsequently post bail out of the quarantine facility!

Posted by: ljk4-1 Jan 3 2006, 03:18 PM

The members of this forum might find this game of interest:

http://members.optusnet.com.au/bnbg6billion/6billionFuture.htm

http://nanodot.org/article.pl?sid=00/08/26/1712213

Lots of good essays, too.

No, I do not know the people who made this game nor am I being paid by them to alert you all to it here.

Posted by: BruceMoomaw Jan 3 2006, 07:40 PM

Personally, given Cruise's behavior last year, I was rooting for the Martians.

Posted by: ljk4-1 Jan 3 2006, 07:43 PM

It amazes me how the human race always seems to be able to defeat any invading aliens, no matter how advanced they are over us (and think about it, that wouldn't take much). And if we don't wipe them out, they always end up being so touched by our tenacity, spirit, and "uniqueness".

In "reality", would a Type 2 or 3 civilization even give a fin-dingle about us, except as an addition to their Galactic Database for completeness?

Posted by: nprev Jan 3 2006, 08:55 PM

Probably not; there don't seem to be any compelling economic reasons for interstellar conquest given all the underlying technology a civilization would have to possess just to traverse interstellar space at all!

Purely academic, anyhow; I'm an adherent of the "smart-aliens-are-really-rare" school of thought, and we're probably the only extant intelligent technological species in the Galaxy during the present epoch. All the more reason not to get wiped out by something stupid like a planetary cross-contamination accident...let's save that for something important like an indigenous pandemic, ecological meltdown, or ideological conflict...

Posted by: ljk4-1 Jan 3 2006, 09:16 PM

I do not appreciate being terrified so early in the new year!

Posted by: Bob Shaw Jan 3 2006, 09:32 PM

You're quite right - no sane intelligent species would go to absurdly expensive lengths to attack somewhere far distant, least of all for resources which are anything but scarce, or even especially needed (as there are bound to be better alternatives).

Except for awl, of course, but that's different.

Bob Shaw

PS Special thanx to Bruce M for learnin' me how to spell 'awl'

Posted by: nprev Jan 3 2006, 11:51 PM

Sorry, sorry...shoulda saved that rap for Halloween!

Posted by: BruceMoomaw Jan 4 2006, 03:10 AM

Damon Knight got so fed up by the late and loony John W. Campbell's insistence that Earthmen must be portrayed as triumphing over all opposition in every story he'd publish in "Astounding Science Fiction" that he finally wrote "The Earth Quarter", a monumentally depressing 1961 novelette in which humans are the ONLY race in the galaxy that's tremendously inferior, both intellectually and morally, to all others -- and in which one embittered military homicidal maniac finally leaves humanity's mark on the galaxy by slaughtering something like a dozen worlds full of peaceful, intellectually dazzling aliens before they finally take him out, due to their reluctance to kill even if it's necessary to keep themselves from being killed.

Personally, I regard it as a matter of racial pride that we will certainly do ourselves in long before any green, scaly-skinned monsters ever come close to getting the chance to kill us. But then, I regard it as pretty much inevitable that every intelligent race in the Universe automatically and unavoidably destroys itself as soon as it achieves our technological level -- I mean, how could they NOT do so, given the weapons for self-destruction (especially the biological ones) that we will very soon have? Admittedly it seems awfully wasteful of God to leave almost all of the Universe unpopulated, and then have every rare intelligent race that DOES turn up in it die off very quickly; but then God never explained Himself very well to Job either.

Posted by: BruceMoomaw Jan 4 2006, 03:17 AM

Of course, there's also Poul Anderson's 1960 story (can't remember its name) in which Earth is visited by star-travelling aliens -- whose technology is so dazzling that it takes a while for us to realize that they're mentally retarded compared to us, and that they got their advanced technology only by working at it for a VERY long time. It ends with the con man who's the first to figure this out selling the aliens the Brooklyn Bridge.

Posted by: ljk4-1 Jan 4 2006, 03:34 AM

Carl Sagan theorized that all violent species destroy themselves before achieving interstellar space flight. But this and your ideas above assume human emotions and behavior for alien beings, to say nothing of what is good and evil.

If evolution means that life evolves differently for every different situation (meaning on other worlds), then perhaps they may not evolve and act as life has done on Earth. What if there are species with hive mentalities, who function as one big unit?

I kinda hate using this example, but the Borg from Star Trek worked as a unified group with the goal of assimilating other cultures to "improve" the quality of their lives, not simply to conquer like an animal taking over another's territory. Just like missionaries did to "primitive" societies, they felt they were doing good for those they saw as less advanced. There may be ETI out there who view us in the same way, but their idea of help and goodness may not be our idea of good.

With literally billions of chances for intelligent life to evolve in this galaxy alone, at least a few should have made it past their "instinctive" stages - assuming they ever behaved in such a way at all. Maybe we are the galaxy's abberation, but to be honest I also think that all biological life on anything resembling an Earth type world at least will evolve in a similar manner.

Growing up in the Cold War, I am honestly amazed that we have survived as long as we have. We are certainly not out of the woods yet, but I think we are also well on the way to achieving a technological ability to transcend our biological selves. Once that happens, I think we will survive indefinitely and no doubt be able to encounter the other beings who also made it to that level.

Posted by: nprev Jan 4 2006, 04:41 AM

Kind of like this topic we've drifted into....

I still think that the simplest answer to Fermi's Paradox may be that intelligence--defined here as technology usage--has no "magic" survival value in the evolutionary sense, and therefore does not necessarily emerge or persist with great frequency throughout the Universe.

We just don't see any real evidence of major engineering works--or their ruins-- that would be expected of a civilization even 50,000 yrs. older than us, much less millions, and that has to mean that they are anything but common. Admittedly, we have just recently acquired the capability to maybe detect and recognize such things, and perhaps technology in any form that is comprehensible to us is a transient thing in the lifetime of a species...but I don't buy it.

I am often tempted to adopt the same viewpoint as Bruce--that intelligent species kill themselves off--but, oddly enough, I am beginning to think that we won't. During this century, at least one nation or consortium of same--don't know who yet, but I have to bet on China or Japan right now-- will establish a permanent, self-sufficient extraterrestrial colony, and once that happens we'll be as unkillable as roaches and spread throughout the Galaxy.

So, basically, my argument is that intelligent, technological life on the average arises in 1 of 400 billion solar systems over a sampling period of maybe 8 billion years...it's not a unique event, but certainly not a common one.

Posted by: BruceMoomaw Jan 4 2006, 05:33 AM

The trouble with "Nprev's theory" -- quite apart from the fact that, wherever we humans spread ourselves, we'll be able to spread our deadly little weapons (especially the biological ones) far more easily -- is that, if his scenario is possible, any SINGLE intelligent species that ever pulled it off would have spread across the Galaxy by now. I have trouble believing that the evolution of intelligent life forms in the galaxy is so rare that we're the very first -- or for that matter the tenth -- to arise in the Milky Way; we are, after all, talking about 400 billion stars. It makes much more sense to assume that, whenever intelligent beings do arise that are capable of technology, they inevitably do themselves in shortly after acquiring that technology.

Posted by: David Jan 4 2006, 06:19 AM

What wonderfully positive thinking. Can I have some of those happy pills you're taking?

Let me see: of those 400 billion stars (I'll accept the number, though isn't it a bit high?) maybe 390 billion are of spectral classes very unlike the sun's, making LAWKI rather unlikely.

Of the remaining 10 billion, let's say 1 in 10 has a planet in the rather narrow habitable zone.

Of that 1 billion, let's say 1 in 100 (I'm feeling generous) develops life.

Of that 10 million, 999 in 1000 permanently remain oceans of monocellular life.

Of the remaining 10,000, 999 in 1000 have a spectrum of multicellular life; there are hundreds of planets on which the most advanced creature is a kind of jellyfish the size of my hand; there are maybe a hundred on which there are large, mobile forms of animal life. In 1 out of a thousand (this is really generous) there are intelligent life forms.

Of these 10, just 1 species has formed the technology to transmit and receive radio signals (5 of the other 10 are still wandering toolless in their planets' equivalents of jungles and savanna; 2 others have developed stone tools; 2 others have developed a metallic technology, but one is illiterate and the other one is still working on the rudiments of geometry).

The 1 remaining species can't figure out how to raise enough funds to go beyond its planet's only satellite, and if this attitude is a fixed characteristic of the species, is unlikely ever to go beyond the edges of its star system.

Now, I pulled all of those ratios out of my rear, um, pocket, except for the number of stars with a G-type spectral class (or something close), which is itself a ballpark figure. But you can see that it is very easy to winnow down the apparently huge "400 billion" figure to something very small. And that has nothing to do with the supposed propensity of civilizations to destroy themselves (one may note that in our sample of one, this has not happened). But with a slightly more optimistic set of ratios, you could "prove" that a Galaxy ought to have a thousand civilizations; and with a slightly more pessimistic set, you could show that 1 civilization per galaxy is on the high end, and it really ought to be 1 civilization per 100 or 1000 galaxies.

Posted by: nprev Jan 4 2006, 08:19 AM

FYI, I got the 400 billion from the last upward revision I thought I saw on the star count of the Milky Way a few months back (think it was on Sky & Telescope's site). It may be too high, of course; my mind is nothing but the finest grade of Swiss cheese!

The main reason that I think technological intelligent life is in fact exceedingly rare in the Universe is that evolution itself seems to be quite dependent on contingency above all else; there does not seem to be any sort of innate bias in the process to produce complex brains or any other sort of adaptation. Mass extinctions on Earth wiped out entire phyla, and the ecology was repopulated by the lucky survivors; obviously, there was no linear Darwinian selection involved in these apparently catastrophic events. We are only here through the most unlikely series of random occurrences over geological time, and had the dice fallen differently even once there would be no technological species on Earth at this time. See Stephen Gould's Wonderful Life for an excellent description of this view of evolution.

Bruce, I think that once we do diversify beyond Earth we as a species will be unkillable because we'll soon cover the Solar System like a fungus, and shortly thereafter also the systems of nearby stars. The human population of the Earth will undoubtedly be decimated or wiped out at some point by wars or a bio-catastrophe as you predict, as will other colonies at different times and perhaps for different reasons...but it won't matter. Once the genie is truly out of the bottle there will still be healthy colonies not affected by such localized catastrophes continuing technological development and territorial expansion. Eventually, we'll be so widespread that we will have mutated (or altered ourselves) into biologically distinct species in different parts of the Galaxy...the "Borg" scenario is also likely to happen for some groups. But, the whole point is that we, or what we will become, will not disappear.

Posted by: Ames Jan 4 2006, 01:07 PM

But the self-extinction clock is ticking. If we fail to found viable self-sufficient extraterrestrial colonies before the buzzer goes, that's it, we will be gone.
Here we have man's next imperative... Exceed or die!

Posted by: ljk4-1 Jan 4 2006, 02:51 PM

The data I have is that of the 400 billion stars in the Milky Way galaxy, roughly half are Sol-type stars, so this should up the ante a bit at least for life in general.

You can add more to the odds in favor of life with the current theories that even red dwarfs may be friendlier to life on any worlds they may have than once thought. They will certainly last far longer than our Sun.

http://www.emse.fr/~yukna/researchers/reddwarf.htm

http://space.com/scienceastronomy/051130_small_planet.html

http://www.kencroswell.com/reddwarflife.html

To put a terrestrial perspective on why it isn't so easy for us to find another world with life - or they us - imagine the stars of the Milky Way as grains of salt. You can hold about 10,000 grains in your hand. To equal the amount of suns in our galaxy, the equivalent amount of salt would fill an average classroom to the ceiling and pour out the windows.

Now find the one yellow dwarf grain in all of that, with the microscopic blue dot circling it.

Posted by: nprev Jan 4 2006, 08:11 PM

Absolutely right. That's why I think its extremely important for MMI & the manned programs of other countries to get going, and get serious. Getting established off-planet is the last "bottleneck" we need to overcome in order to guarantee long-term survival of the human race.

Posted by: David Jan 4 2006, 08:26 PM

But the obstacle that needs to be overcome in this case is not going "off-planet", but constructing wholly enclosed self-sustaining systems which can keep going without being continually resupplied from Earth. You can work on that without having much or anything in the way of access to space (after all, these systems could just as well be deep underground or undersea); but we are a very, very long way from being able to do that. The "Biosphere" debacle showed just how difficult the task really is. The ISS needs to be continually supplied from earth, as would any Moon base or Mars colony. If Earth suddenly lost the ability to communicate with her colonies, they would become extinct in a matter of months, or, at best, a few years.

If you really think that the survival of humanity is dependent upon its spread beyond Earth, researching long-term survival of enclosed compounds with access to few resources other than solar power might be the best contribution to be made at this stage -- because even a revolutionary new propulsion system wouldn't take care of this problem.

Posted by: Ames Jan 4 2006, 09:03 PM

Ok, I don't say we are close to achieving either off-planet self sufficient colonies or complete annihilation in the near future.
But in the long-term we must be sure that we do the first before the second.
And the way things are going, it doesn't look too promising.
Biospheres are fascinating and much underresearched. There are a whole spectrum of recycleablilty issues which if solved could do a lot to fend off the annihilation scenario as well.

Nick

Posted by: nprev Jan 4 2006, 09:04 PM

Of course; implicit in all this is the need to develop supporting technologies such as methods of generating cheap, abundant power and extracting resources from indigeneous sources, and a lot of this should happen as "spin-offs" as we begin to establish a long-term presence on the Moon and Mars. The whole point is that we need to get started like yesterday...

Posted by: BruceMoomaw Jan 4 2006, 10:10 PM

Every one of those colonies will be just as capable of having a tiny fraction of its population whip up doomsday plagues, accidentally or deliberately -- and most of them will also be capable of constructing nuclear weapons. It's possible, though, that if humanity gets so far as to spread colonies all over the Solar System (which I very much doubt it will do, for the reasons I've already given), a very SMALL number of humans may continue to be alive at any given time. Thrillsville.

Posted by: nprev Jan 4 2006, 11:01 PM

"It ain't much, but it's all we got"...

Mass extinctions work exactly the same way; the whole reason that life on Earth has survived as long as it has is that it's colonized every possible environment, and a very small number of survivors make it through the catastrophe through sheer luck. Nihilistic though it may be, widespread colonization is a proven survival strategy, and we would be wise to emulate it...

Posted by: ljk4-1 Jan 4 2006, 11:04 PM

Scientists engaged in the study of human origins have advanced a new theory which suggests that we very nearly failed to evolve to where we are today.

American and Russian researchers have published DNA research suggesting that the human gene pool almost ran dry around 70,000 years ago. They think the total population of our human ancestors fell as low as only a couple of thousand individuals.

If true, it means humankind was dangerously close to being wiped out by disease or environmental disaster.

The theory also revives the scientific debate over whether modern humans evolved in Africa, the so-called "Out of Africa" theory, or whether they evolved independently in locations around the globe.

The rest of the story is here:

http://www.abc.net.au/pm/content/2003/s876620.htm

Posted by: Bob Shaw Jan 4 2006, 11:10 PM

There have been studies which suggest that for humanity there was a 'pinch point' where less than a hundred individual humans were alive, just before the explosion of Modern Humans into the world. If we, the rag-tag band's descendents, can do so much today, then can we dismiss the potential in even a similarly small group of our descendents? I think not.

For my money, however, our real descendents will be AIs of one form or another.

Me, I can't wait to get out there so that we can EXTERMINA-A-A-A-ATE a few lowly competitors...

...hmmm, I wonder if there's a term for Daleks in the Drake Equation?

Bob Shaw

Posted by: nprev Jan 4 2006, 11:23 PM

Interesting and very pertinent article, ljk4-1; thanks!

If this is true, and it seems quite likely, then that near-miss serves as sufficient rationale for aggressive extraterrestrial colonization. Something will eventually happen; it always has, and it always will, so we'd better be ready as a species to deal with it.

Posted by: ljk4-1 Jan 4 2006, 11:27 PM

Oh, great, Bob - now the Advanced AI Overlords of the Galactic Federation are going to read this (they're tapped into all communication networks no matter how primitive, using the CosmoGoogolplex search engine) and come to eliminate us before we decimate the galaxy, thus fufilling certain prophecies in this thread.

http://www.orionsarm.com/main.html

Or maybe they'll just quarantine us for a few galactic revolutions, until we've grown up or bumped ourselves off or another species has evolved into dominance.

Expect New Horizons to make a sudden thud against an immense invisible barrier surrounding the Sol system somewhere in the Kuiper Belt.

Posted by: Bob Shaw Jan 4 2006, 11:45 PM

'Oh, dear, was it something I said?' might make an excellent SETI message, then!

Better than 'Was it something I ate?' I suppose...

Bob Shaw

Posted by: lyford Jan 5 2006, 12:03 AM

Or http://www.cgoakley.demon.co.uk/vlhurgs/

Posted by: David Jan 5 2006, 12:21 AM

There's some dubious interpretation of the evidence going on here. If the entire human race can be traced to a population of c. 2,000 individuals at 70 KYA, that doesn't mean that those were the only humans around then; it means that only that group of humans left descendants that survive to the present day.
In fact, we know quite well that there were lots of other branches of the genus Homo that were around at 70KYA: Homo neanderthalensis in Europe and the Middle East, a surviving subspecies of Homo erectus out in the far East, probably other subspecies of Homo sapiens wandering around Africa, and of course the famous Homo floresiensis in Indonesia.
The "2,000 individuals" (assuming the figure is about right) may represent not so much a bottleneck resulting from disease or famine (or, for that matter, war; we are after all talking about humans!) as a small, genetically innovative group, which (by choice or biology) did not successfully interbreed with other members of their own genus, but who in the long run turned out to be very successful reproductively.

Posted by: Stephen Jan 5 2006, 01:34 AM

How are you defining "Sol-type Stars"?

If we don't count white & brown dwarfs, the overwhelming bulk of stars in the galaxy are red dwarfs, which I would hardly classify as "Sol-type" stars. For example, the table on http://www.daviddarling.info/encyclopedia/S/starsnumbers.html (which assumes a total stellar population of 400 billion for the Milky Way) puts them at over 70%.

(Such numbers are still only guesstimates, of course. But that said if you look at lists of stars closest to the Sun, where our statistics are most complete, such as the http://www.chara.gsu.edu/RECONS/TOP100.htm, most are red dwarfs; and many of the remainder are at the dim end of the K spectral type.)

Posted by: David Jan 5 2006, 02:19 AM

Hm, it certainly looks as if my 10 billion guess was a lowball; the number is presumably in the range 10 billion - 100 billion. Still, even not changing any of my assumptions (which are of course all dubious, and in my opinion, excessively optimistic), that would put the number of technologically advanced civilizations in a galaxy in the range 1-10.

Posted by: dvandorn Jan 5 2006, 02:40 AM

Darnit, I just sent my bejeweled battle shorts out to be polished!



-the other Doug

Posted by: dvandorn Jan 5 2006, 02:42 AM

So, the reason we're here is because we're all pre-occupied with sex?

I'll have to remember that line... er, um, I mean, that fact.



-the other Doug

Posted by: Stephen Jan 5 2006, 07:16 AM

Um, when you talk about "mass extinctions" are you including bacteria & other single-celled life as well or only multi-celled organisms like vertebrates, arthopods, etc? That is, the sort that tend to leave fossils versus the sort which do not (but on the other hand are more the sort which truly have "colonized every possible environment", including places of a more extreme sort such as hot springs, nuclear reactors, & deep inside the Earth).

I mention that because if, as you suggest, "the whole reason that life on Earth has survived as long as it has is that it's colonized every possible environment", then that statement surely only applies if you're either talking about life as a whole or only about the kind of life which truly has "colonized every possible environment"--namely, single-celled organisms. It does not really apply to the rest of us; for the rest of us, especially vertebrates, have been much more selective in the kinds of environments we inhabit.

For example, only a small proportion of mammal & bird species live in the sea; and of those which do, none at all (AFAIK) live permanently underwater (unlike, say, fish). All must come to the surface periodically to at least breathe.

Posted by: tty Jan 5 2006, 07:32 AM

This is not a new idea. It has been known for quite a while that there is surprisingly little genetic variation in Homo sapiens (much less than in our sister taxon the chimpanzees for example) and that the most likely explanation is a fairly recent population bottleneck. It has also been suggested that the bottlenecking might be due to the Lake Toba eruption about 70,000 years ago. This was one of the largest single volcanic eruptions known (perhaps even the second largest known during the Phanerozoic) and caused six years of fully glacial climate during the otherwise mild OIS 5a interstadial.
Note however that Lake Toba was not bad enough to cause a mass extinction. There isn't even minor extinctions known at that particular time.

It is true that there was probably at least three other hominid lineages around at that time (erectus, neanderthalensis and floresiensis). The fact that they don't seem to have left any traces in the human gene pool together with Homo sapiens' well documented preoccupation with sex suggests that they did not, and probaly could not, interbreed successfully with sapiens.

I certainly agree with the importance of remnant survivor populations. The really bad mass extinctions (Late Ordovician, Late Devonian, P/Tr, Tr/J, K/T) killed off the majority of species and must have killed off even larger proportions of individual organisms (the possibly 96 %(!) of species eliminated by the P/Tr extinctions probably translates to something like 99.99999... % of individuals). Everything alive is descended from that vital 0.0000...1 percentage.

tty

Posted by: nprev Jan 5 2006, 08:00 AM

I did mean all life, Stephen, but I was using the example of life's ability to survive Earth's mass extinctions as a model for the strategic dispersion, if you will, of humanity throughout the Solar System and eventually throughout the Galaxy as insurance against the demise of the species.

I did not mean to suggest that humans can and should adapt themselves to radically new environments--although I suspect that some of that will ultimately occur through both natural selection and artificial means over the ages in many different locales. Generally, I would expect us to develop very reliable and efficient technologies that will allow us to exist and thrive on uninhabitable worlds like Mars and the Moon, probably terraform planets when practical, and colonize Earth-like worlds opportunistically.

The other thing I would expect is complete anarchy at the megascale. I don't ever see a Galactic Empire coming into being; in fact, I doubt that any given world would even know about more than the nearest two or three hundred of its neighbors, assuming that it was at a cultural and technological peak and not in a Dark Age. Wars will still happen, and some places will blow themselves up or overpopulate, etc., etc...but humanity as a species will survive, and as cultures ascend technologically more and more colonization will occur.

Maybe some day one of these vigorous new cultures will rediscover the Solar System and make the archeological breakthrough from studying ruins throughout the system and what's left of Earth that here was the birthplace of it all...

Posted by: Stephen Jan 5 2006, 09:43 AM

That's assuming that the catastrophes which caused the mass extinctions were as bad as they are sometimes made out to be. Vast numbers of (multi-cellular?) species may well vanish from the fossil record, yet I note that even during the Permian extinction event, which was the worst we know of, (AFAIK) life did not have to crawl up out of the sea a second time to re-populate the land; while the so-called KT event at the end of the Cretaceous did not (again AFAIK) require even North America be repopulated from other continents following that meteor strike.

In other words, life did not need to be too dispersed in order to survive. That sort of suggests "strategic dispersion" of humanity out among the solar system may not be necessary to survive a KT-style catastrophe. Enough human beings might well survive even on Earth to carry on the human race.

If so, then the real problem is not so much whether humanity itself survives as whether technological civilisation would survive as well; or if not whether it would be recoverable. If it doesn't and it can't, then the human race would thereafter be confined to the Earth. Which in turn would mean that even if humanity should survive another dozen mass extinctions it is unlikely to survive the last, when the Sun swells into a red giant billions of years from now and turns the Earth (assuming the planet itself survives) into a burned out cinder.

What that means is that what you would be trying to preserve by a "strategic dispersion" of humanity out among the solar system (and beyond) is not just the human race itself but the technological civilisation that will (eventually) allow the human race to escape the fate that would otherwise be meted out to it as the Sun nears the end of its own life. To preserve that will require more than simply dispersing humanity around the solar system (or even beyond). If those colonies are still dependant on Earth's technology for their own survival then destruction of Earth's technology through a KT-style event would probably also means curtains for them as well. For example, lunar colonies may well be producing their own oxygen from lunar rocks. However, if the machines which produce that oxygen still depend on spare parts from Earth, then no more spare parts from Earth would eventually mean that those machines are going to break down and thus stop producing oxygen.

To ensure the survival of those machines, and thus those colonies, the technology itself (and associated infrastructure such as factories) is going to have to be strategically dispersed as well as the human race.

Posted by: Bob Shaw Jan 5 2006, 01:24 PM

other Doug:

Well, yes, us and the Bonobos have societies, and even our species, based round sex, sex, sex. We're not Rational Animals, we're Martini Animals - any place, any taste, any time!

Now, anyone want to hear any of my poetry?

Bob Shaw

Posted by: ljk4-1 Jan 5 2006, 02:58 PM

Have you been reading Asimov again:

http://www.slawcio.com/foundation/cover.html

If there aren't ETI in the galaxy now, some day there will be.

If we can place information records about humanity and Earth all over the galaxy, we will make their rediscovery job easier.

Posted by: ljk4-1 Jan 5 2006, 09:46 PM

Science/Astronomy:

* Half a Dozen Stars Born in Milky Way Every Year

http://www.space.com/scienceastronomy/060104_star_birth.html

Astronomers have the best evidence yet pinning down how just many stars form in
our galaxy every year: about half a dozen.


* Reacting to Disaster

http://www.space.com/searchforlife/seti_vakoch_react_060105.html

The scenario is familiar from Hollywood blockbusters like Armageddon and Deep
Impact. A massive asteroid—perhaps ten miles in diameter—is headed straight for
Earth. An all-out effort to deflect it is mounted. If the mission succeeds,
civilization as we know it will continue.

Posted by: nprev Jan 5 2006, 11:23 PM

I'm ashamed to admit this, but I never have read the Foundation series...guess I should, given my convictions!

Posted by: BruceMoomaw Jan 6 2006, 04:39 AM

Speak of the Devil -- Mickey Kaus has been thinking the same thing, and he isn't the only one either:

http://www.slate.com/id/2133648/&#betelgeuse

Posted by: nprev Jan 6 2006, 05:26 AM

Hmm...seems like this idea, like all great ones... , is taking root simultaneously in many minds!

Well, in the interest of analyzing alternatives, does anybody have any solutions to the problem of long-term species survival other than massive space colonization to kick around?

Posted by: dvandorn Jan 6 2006, 11:38 AM

Hmmm... species survival...

Yes, there is a better way. Research human consciousness until we fully understand every mechanism, and then genetically alter the basic human genome to remove such psychological traits as contentiousness, agressiveness, and fear-based responses.

And arrange it such that there are no unaltered sociopaths, monomaniacs or megalomaniacs -- either during or after the change-over -- who could take improper advantage of the process.

Now, as a theory, the above only resorts to one single step in which a miracle occurs (and I bet some of you won't see which step that is). Doesn't that make it an acceptably testable theory?

-the other Doug

Posted by: nprev Jan 6 2006, 11:49 PM

Actually, I see two miracles required in your proposal:

1. Global consensus to alter our genome as you propose (...which, by the way, would probably also take out our drive to explore or innovate at all, and just possibly our willingness to face danger, period; probably very bad things to lose).

2. 100% elimination of maniacs; after all, it would probably take one hell of a mono+megalomaniac or consortium of same to implement miracle #1 in the first place! (I'm thinking Feric Jaggar from Spinrad's The Iron Dream, here...)


I still gotta go with extraterrestrial colonization, man; sorry!

Posted by: ljk4-1 Jan 12 2006, 08:52 PM

The Doomsday Vault

The future of humanity could lie within a large concrete room, hewn
out of a mountain on a freezing island just 1000 kilometres from the
North Pole. The facility is designed to hold around 2 million types
of seed, representing all known varieties of the world's crops. New
Scientist has learned that the Norwegian government is planning to
create the seed bank next year to safeguard the world's food supply
against nuclear war, climate change, terrorism, rising sea levels
and earthquakes...

http://www.newscientist.com/article.ns?id=mg18925343.700

Posted by: ljk4-1 Jan 16 2006, 04:57 PM

Science Analysis of the November 3, 2005 Version of the Draft Mars Exploration Program Plan

January 6, 2006

Prepared by the MEPAG ‘2005 Mars Program Plan Science Analysis Group’

Purpose and Scope:

The purpose of this report is to provide comments on the draft Mars Program Plan for the next decade. Specifically, comments are provided on the version of the plan presented during the MEPAG Meeting on November 3, 2005. These comments are authored by the Draft Program Plan Science Analysis Group (SAG). The SAG was chartered by MEPAG to consider the extensive discussion and input about the draft plan from the MEPAG attendees, together with analyses conducted by the SAG, and to provide a report that delineates the strengths and weaknesses of the draft plan, together with possible alternative approaches. Further, the SAG considered the overarching scientific themes for the next decade of Mars exploration and the technological infrastructure needed to implement the plan and viable alternatives.

http://mepag.jpl.nasa.gov/reports/Mars_Progam_Plan_SAG_report.doc

Some mission dates after MSL from the report:

· 2011/2013 Scout and core science orbiter with telecommunications capability
· 2016 Mid-rovers or Astrobiology Field Laboratory
· 2018 Scout
· 2020 Planetary Evolution and Meteorology Network
· 2022 Mars Sample Return Orbiter with Telecom
· 2024 Mobile Mars Sample Return

Looks like manned Mars missions won't even start until at least the 2030s. But by then, the question is, will AI and robot technology be at a point where humans would be less efficient and more expensive in terms of science data return?

Posted by: BruceMoomaw Jan 23 2006, 08:44 AM

That report actually raises all sorts of interesting questions and debatable points, which I don't have time to list right now but which you guys should be able to catch. I intend to ask a member of the report team some of those questions

Posted by: BruceMoomaw Jan 24 2006, 10:22 PM

In the "MSL landing site" thread, I promised to mention an alarming -- and entirely new -- possible show-stopper in the near-term search for Martian organics that's turned up in the new MEPAG report. Here it is ( http://mepag.jpl.nasa.gov/reports/Mars_Progam_Plan_SAG_report.doc ):

"One issue raised during the MEPAG Meeting was that cosmic rays and their spallation products over the aeons may have caused organic compounds to convert to graphite for deposits that have remained within the top meter from the surface. Therefore drilling to depths beyond a meter was suggested to ensure access to any organic materials. The contention that organic material within a meter of the surface would be destroyed needs quantification, both the process and the timescale. Further study is also needed to understand the extent to which surfaces have remained static for aeons. Certainly MER and orbital observations show extensive burial and erosion by wind, water, and volcanism at many locations and scales. Lateral mobility conceivably could access materials that have been exhumed relatively recently from depths > 1m. The SAG also notes that the requirement for vertical mobility to access unprocessed carbon compounds will be better understood following the results from the evolved gas analyzer (TEGA) that is part of the payload on the 2007 Phoenix Lander mission. MSL results will also provide direct information on the depth distribution of reduced carbon compounds. The SAG’s opinion is that lateral mobility, with AFL or mid-range rovers, is more important for the 2016 opportunity than extensive vertical mobility (i.e., > 1 m)."

Hmmph. Well, if MSL doesn't turn up any trace organics, we're going to have to think twice about whether that last statement is really correct, or whether we ought to be thinking seriously about a 2016 mission (maybe even a stationary lander) with a much longer drill.

The report, by the way, really doesn't place as much emphasis as I'd expected from last January's Mars Strategic Roadmap meeting on the importance of finding trace organics with either MSL or the 2016 lander in order to target the first sample-return mission -- NASA's Mars people, when testifying at that meeting, talked about this repeatedly. I myself wouldn't dare fly a sample-return mission until either such organics have been found, or in-situ searches for them in several different places have all come up empty.

All this also reconfirms my belief that Phoenix, stationary or not, will be a VERY interesting mission to watch, simply because it will be the first successful lander (we hope) since the Vikings to look for organics, and should be much more sensitive to them than the Vikings.

Posted by: AlexBlackwell Feb 15 2006, 01:29 AM

MEPAG's Mars Scientific Goals, Objectives, Investigations, and Priorities document has been updated. See http://mepag.jpl.nasa.gov/reports/index.html.