[X] My Assistant

[elakdawalla]

I just wanted to know if any other UMSFers are going to be in lovely Clear Lake, Texas for LPSC. I'll be there all week, Monday through the middle of Friday. While I don't think there'll be enough of us to generate our own party, perhaps we can plan to all attend one of the various social gatherings and meet up and raise a glass to Doug.

I'm not sure when or where the parties are yet, but they'll be late because they've really packed the schedule following the sessions this year. Here's what's happening in the evenings:
Sunday 5 pm: Registration/Reception
Monday 5 pm: We get to watch the NASA HQ sacrificial lamb get stoned to death by the meeting attendees, i.e. "NASA Headquarters briefing," followed by the "Student/Scientist Reception" from 6 to 8 (free food, I think)
Tuesday 5:30 pm: Special session on the Phoenix landing site, followed by poster session at 7 pm
Wednesday 5:30 pm: Special meeting on "Return to the moon," followed by Cocktail Hour and Buffet Dinner from 6 to 9:30
Thrsday 5:30 pm: Special session on Planetary cartography (Phil??) followed by poster session at 7 pm

So it'll be busy but we've got to have some fun. I'd just like to see a show of hands of who else may be there, then we can talk here after we start arriving in Houston and we figure out when and where the various parties are, and where we should raise the UMSF flag. Well, I don't have a flag, but at least I have a T-shirt.

--Emily

[Phil Stooke]

Most unfortunately I will not be there this year. But I do hope to go next year. LPSC has always been a highlight of my year. It's 20 years since my first one. Phil

[volcanopele]

I'll be there. There was a great party last year at this barn out in the middle of nowhere. Bob P. knows what I am talking about. Wonder if there will be a similar one this year. I remember another party last year at a bar down the street from the Conference center, but it wasn't as good. Felt like a sardine...

We could organize a UMSF lunch, maybe on Tuesday. We sorta had one last year at this bar on Nasa road 1. I know CosmicRocker was there (I think...). My memory of last year's LPSC is rather vague unfortunately.

[edstrick]

Unfortunately, I've not made an LPSC since about 88 or 89, due to employment and due to increasing elder-care loads.

They used to have a regular chili-cookoff with different departments from instututions and universities coming up with evil brews.

They never did have anybody serve Chili-con-Alien, which was served at a St. Louis SF club party I (perhaps fortunately) missed. The alien was chopped squid. Overcooked. Like rubber bands with suckers.

But the *idea* is perfect!

[elakdawalla]

Unfortunately, I've not made an LPSC since about 88 or 89, due to employment and due to increasing elder-care loads.

They used to have a regular chili-cookoff with different departments from instututions and universities coming up with evil brews.

The chili cook-off was replaced a couple of years back by the banquet. But not before my pals from Brown came in with their long-awaited entry of "New England Clam Chili." Mmmmm.

--Emily

[CosmicRocker]

I will be there for at least some of the festivities, but I too have employment and elder-care issues to deal with. So, I'll probably only be able to drive out for some of the days. Hopefully, I can make it to wherever it is that the flag is raised, whenever that may be.

Coincidentally, tonight I was about to resurrect an old topic in Opportunity, where we first mentioned this conference, but then thought to check to see if someone else had already done so elsewhere. This is a better place for it, but the chit-chat channel does not get the traffic many of the other areas of this forum do. It wouldn't hurt to drop some hints elsewhere in the forum, with the hope of attracting others. I'll revive that topic there and point people back to this topic.

This should really be a terrific conference. I think it will actually be unbelievably interesting with the diversity of missions that are supposed to be reporting back. Early registration has closed, but anyone can shell out the $90 ($65, student) at the door. Don't tell anyone, but you might be able to just walk in and partake without registering if you don't make a lot of noise. Although I registered for previous events, no one ever asked to see my ticket. But if you have the money to spare, I wouldn't deny it to a wonderful organization such as the LPSI.

I'm hoping to meet some of you, and perhaps share the latest gossip about Home Plate, Hayabusa, Stardust, Deep Impact, etc.

[volcanopele]

I would like to organize something with all the UMSF LPSC participants. Perhaps for lunch on Tuesday at Double Dave's Pizzaworks?

http://yp.yahoo.com/py/ypMap.py?Pyt=Typ&tu...r:regT:20:fbT:0

[Guest_AlexBlackwell_*]

I would like to organize something with all the UMSF LPSC participants. Perhaps for lunch on Tuesday at Double Dave's Pizzaworks?

Only if you're treating

[Phil Stooke]

"The chili cook-off was replaced a couple of years back by the banquet. But not before my pals from Brown came in with their long-awaited entry of "New England Clam Chili." Mmmmm.

--Emily"

Maybe that's why it was cancelled...

Phil

[elakdawalla]

I would like to organize something with all the UMSF LPSC participants. Perhaps for lunch on Tuesday at Double Dave's Pizzaworks?

http://yp.yahoo.com/py/ypMap.py?Pyt=Typ&tu...r:regT:20:fbT:0

Count me in. I'll have a car so can offer rides.

--Emily

[CosmicRocker]

I will try to make it on Tuesday, but I am limited on the number of days I can take off next week. I really have to make the Wednesday prime time shows.

I thought I'd add a quick note in case there are folks coming in from out of town who may not have been able to see the Roving Mars Imax in their towns. Not that the LPSC will leave you with a lot of free time, but the Imax in Houston (at the Houston Museum of Natural Science) will be running it. http://www.hmns.org/see_do/imax.asp?r=1

[djellison]

I might mention this during the next Pancam update - as I'm hoping to get one done before then

Doug

[Guest_AlexBlackwell_*]

Count me in. I'll have a car so can offer rides.

Scene: Interior of Delta House
[Simultaneously, while looking at each other]
Otter/Boon: "Road trip!"

[volcanopele]

Scene: Interior of Delta House
[Simultaneously, while looking at each other]
Otter/Boon: "Road trip!"

I just talked to Bob P., and he said he'd try to come. Be forewarned that I just got a very drastic help so my recent photo in the Tucson Citizen may not help.

I'll meet all who are going tomorrow after the morning sessions at one of the tables outside the lobby doors (the "lunch area")

[Guest_AlexBlackwell_*]

Be forewarned that I just got a very drastic help so my recent photo in the Tucson Citizen may not help.

OK, I'll bite. What is "a very drastic help"?

[volcanopele]

OK, I'll bite. What is "a very drastic help"?

haircut, I meant haircut. Which may explain the mental malfunction you point out.

[Phil Stooke]

How will people be able to distinguish volcanopele from Bob P now?

Phil

[elakdawalla]

So here's the photo from lunch. Left to right: Tom Swulius, lurker Jeff Moore, me, Jason Perry, and Bob Pappalardo. Note that Tom and I are modeling our highly fashionable UMSF shirts!

--Emily

Attached thumbnail(s)

 

[Guest_AlexBlackwell_*]

How will people be able to distinguish volcanopele from Bob P now?

Well, based on the picture Emily just posted, I don't think that's going to be a problem now

[Guest_AlexBlackwell_*]

BTW, Mark Peplow of Nature is also blogging the conference.

[Guest_AlexBlackwell_*]

Emily keeps pounding out new blog entries from LPSC.

[Tom Tamlyn]

BTW, Mark Peplow of Nature is also blogging the conference.

Those who enjoyed the feast of information and insights so generously served up on Oliver Morton's Mainly Martian site will be pleased to see that some of the comments on the Nature blog are by Morton, although he is not at the conference.

TTT

[Guest_AlexBlackwell_*]

Those who enjoyed the feast of information and insights so generously served up on Oliver Morton's Mainly Martian site will be pleased to see that some of the comments on the Nature blog are by Morton, although he is not at the conference.

I just saw on Oliver's Mainly Martian blog something that I had recently heard: he is now Chief News and Features Editor at Nature. Congratulations, Oliver!

[The Messenger]

Emily keeps pounding out new blog entries from LPSC.

Cleave: "What we did in trying to build this budget, we had unexpected budget liens in the shittle program. And those liens needed to be covered.

That would be a Fruedian typo

[ugordan]

Good to finally see some new posts on Oliver's blog, after many months of silence I was beginning to wonder what ever happened to him.

Seems he's perfectly fine

[elakdawalla]

That would be a Fruedian typo

Yes, Freud would love the fact that I CANNOT seem to be able to type "Space Shuttle" without typing "Shittle" first.

Should have spell checked, but I'm not sorry a few of you saw that before I fixed it...

--Emily

[Guest_AlexBlackwell_*]

Yes, Freud would love the fact that I CANNOT seem to be able to type "Space Shuttle" without typing "Shittle" first.

That's understandable. Frankly, if it had been me, I probably would have "accidentally" screwed up some names (à la ESPN's Chris Berman):

Mary "Who Is Getting Harder and Harder To Be(lieve)" Cleave or, better still, Mary "Budget" Cleav"er"
Andy "Tap" Dantzler

[volcanopele]

mmm, that was good pizza. I will try to post on the Cassini sessions tomorrow in the Cassini/Huygens forum. I won't beat Emily to the punch with my Palm keyboard lacking a functioning "C" or "D" (thankfully this is a PDA so I can use Graffiti to "type" those letters, but it is still annoying to have to pause every time I neeb to use those letters), but I will try to write up some good notes, though don't expect great notes for the ISS talk, I've basically heard it already.

BTW, Doug called in to the lunch. Sorry I wasn't more talkative but that place was quite loud at the time.

[Guest_AlexBlackwell_*]

That's understandable. Frankly, if it had been me, I probably would have "accidentally" screwed up some names (à la ESPN's Chris Berman):

Mary "Who Is Getting Harder and Harder To Be(lieve)" Cleave or, better still, Mary "Budget" Cleav"er"
Andy "Tap" Dantzler

Angry Scientists Confront NASA Officials at Conference
By Leonard David
Senior Space Writer, Space.com
posted: 14 March 2006
03:50 pm ET

[djellison]

Should have spell checked,

No you shouldnt. Change it back

Good to speak to Emily and Jason at the Pizza place, a chance to say thank you for their contributions as co-admins (essentially, my minions) off this place

Doug

[Guest_BruceMoomaw_*]

All those scientists who came within a hair of lynching Cleave and Dantzler today, however, had better make up their minds just what the hell they are actually going to demand as a remedy for the situation. Are they going to demand an increase in NASA's total budget, or are they going to demand that money be pulled out of Shuttle/Station and moved to NASA's other branches? Well, you all know what I favor -- but the longer they can't decide which of these courses to recommend, the longer they will be relatively ineffective.

And being "polite" to this particular administration -- in the event there's anyone out there who has failed to notice by now -- doesn't produce much in the way of results. Angry yelling and threats occasionally do.

[edstrick]

Not that it helped much under the previous administration, either, where the post-inflation NASA budgets decreased each year except the last, when, like pretty much all administrations with somebody up for re-election, they boosted the budget to buy votes.

I want to vote for Teddy Roosevelt... He'd fund space exploration properly! (last (expletive-deleted) competent president we had, I'd swear!)

[volcanopele]

Not sure which session Emily was in this morning, but I was at the Titan session. Took about 6 pages worth of notes. I will try to get those typed up and posted in the Cassini forum either tonight or tomorrow. I'll do the same thing with the Icy Sat session this afternoon.

I even asked my first questions during a session. Hopefully they at least reminded the audience that ISS can see the surface, albeit at lower spatial resolution than SAR imaging or the very highest res VIMS stuff. But keep in mind that at the 2 km/pixel scale, we have seen far more of the surface.

BTW, the snail is called Tortola Facula now. Did the VIMS folks not get that memo?!?

[Guest_AlexBlackwell_*]

Phil Plait has a new update on "NASA Night."

[Guest_BruceMoomaw_*]

At the Europa Focus Group meeting, Torrance Johnson told me a tale which may explain why Pres. Carter never backed a US Halley's Comet mission. After considerable effort, Univ. of NM comet specialist Jack Brandt finally got an audience with Carter's national security advisor Zbigniew Brzezinski and gave him the full-court press, ending by showing him a spectacular photo of Halley. Brzezinski looked at it and grunted, "Hmmph. Looks like a [vulgar term for significant portion of the male anatomy]." That was his only comment during the presentation, and probably his only comment to Carter on the subject later -- and Brzezinski was hardly reflexively anti-science. (Eight years earlier he had written a book called "Between Two Eras: America in the Technetronic Age".)

Space scientists are advised to keep this story in mind whenever they're tempted to believe that their subject absolutely MUST be of interest to the general public.

[Stephen]

All those scientists who came within a hair of lynching Cleave and Dantzler today, however, had better make up their minds just what the hell they are actually going to demand as a remedy for the situation. Are they going to demand an increase in NASA's total budget, or are they going to demand that money be pulled out of Shuttle/Station and moved to NASA's other branches? Well, you all know what I favor -- but the longer they can't decide which of these courses to recommend, the longer they will be relatively ineffective.

I'd have thought there was a simple principle space scientists should all be following here: Don't do unto others what you would not want done unto yourself.

If space scientists don't like the prospect of (say) a future Europa orbiter's budget being raided to help fund a Titan balloon mission they should not start the ball rolling by raiding the shuttle and/or ISS's stash to fund the Europa orbiter.

That said, calls to lift NASA's total budget seems unlikely to be heeded any time soon either, at least by any substantial amount. Congress may increase it for favoured projects like the New Horizons Pluto mission or the VSE, but not overall. But then the reverse also applies in a sense. If the shuttle, ISS, and VSE were all abolished tomorrow most of the money allocated to those would not go to NASA's "other branches". The lion's share would go back into general revenue for funding other areas of government or for distribution to the voters as tax cuts.

Like it or not, putting people in orbit (or on the Moon or Mars) is what gets Congress to open its cheque book. They will not pay the same amount of money to put little robots up there no matter now clever or photogenic they may be.

======
Stephen

[Guest_RGClark_*]

I'd have thought there was a simple principle space scientists should all be following here: Don't do unto others what you would not want done unto yourself.

If space scientists don't like the prospect of (say) a future Europa orbiter's budget being raided to help fund a Titan balloon mission they should not start the ball rolling by raiding the shuttle and/or ISS's stash to fund the Europa orbiter.

That said, calls to lift NASA's total budget seems unlikely to be heeded any time soon either, at least by any substantial amount. Congress may increase it for favoured projects like the New Horizons Pluto mission or the VSE, but not overall. But then the reverse also applies in a sense. If the shuttle, ISS, and VSE were all abolished tomorrow most of the money allocated to those would not go to NASA's "other branches". The lion's share would go back into general revenue for funding other areas of government or for distribution to the voters as tax cuts.

Like it or not, putting people in orbit (or on the Moon or Mars) is what gets Congress to open its cheque book. They will not pay the same amount of money to put little robots up there no matter now clever or photogenic they may be.

======
Stephen

The only difference is the people who support the shuttle and/or the ISS are not scientists.


- Bob

[ljk4-1]

At the Europa Focus Group meeting, Torrance Johnson told me a tale which may explain why Pres. Carter never backed a US Halley's Comet mission. After considerable effort, Univ. of NM comet specialist Jack Brandt finally got an audience with Carter's national security advisor Zbigniew Brzezinski and gave him the full-court press, ending by showing him a spectacular photo of Halley. Brzezinski looked at it and grunted, "Hmmph. Looks like a [vulgar term for significant portion of the male anatomy]." That was his only comment during the presentation, and probably his only comment to Carter on the subject later -- and Brzezinski was hardly reflexively anti-science. (Eight years earlier he had written a book called "Between Two Eras: America in the Technetronic Age".)

Space scientists are advised to keep this story in mind whenever they're tempted to believe that their subject absolutely MUST be of interest to the general public.

Wait a minute - what photo of Halley did he show? The Giotto mission wasn't until
1986, when Reagan was in office.

And don't you love the arrogance of power - the guy couldn't even make some
courteous comments about the presentation, even if he wasn't into the subject.

And for the scientist - the public doesn't always want or need every little detail
on a subject. I've seen that in way too many lectures for the public by scientists
who are only used to talking to their fellow scientists.

Jimmy Carter is proof that just because you are an intelligent person (at least
more intelligent than a lot of other presidents) does not automatically equal
support of the space sciences. Even Carl Sagan could not convince Carter
to give funds for planetary missions. And to think his message is the one on
the Voyager Interstellar Record. Just like Nixon's signature is on all those
Apollo LM plaques, I suppose.

http://en.wikipedia.org/wiki/Voyager_Golden_Record#Contents

[dvandorn]

Like it or not, putting people in orbit (or on the Moon or Mars) is what gets Congress to open its cheque book. They will not pay the same amount of money to put little robots up there no matter now clever or photogenic they may be.

Thank you, Stephen. Exactly spot-on.

-the other Doug

[The Messenger]

...

Like it or not, putting people in orbit (or on the Moon or Mars) is what gets Congress to open its cheque book. They will not pay the same amount of money to put little robots up there no matter now clever or photogenic they may be.

I can't help but get a visual image of a sow drying up, and all the piglets squealing. The in-fighting is indeed dangerous. I know, for example, Cassini benefitted directly from shuttle dollars. It can be argued that Robert Park's campaign to put a hole in the bulkhead of the ISS has lead indirectly to the dry-up of science funding. For a politician, where half the people love dogs and half the people hate them, the best thing to do is stay out of the limelight on the issue...and quitely pay the bills for both the dog catcher and the shelter.

Ironically, Carter was a true conservative, and very concerned about the future and US dependence upon foriegn stuff. The shuttle was tailored to his style: reusable and (it was sold as) relatively cheap. I suspect that if he had a chance to do it over, he would have pushed a well funded planetary exploration program - what a great legacy!

[djellison]

Wait a minute - what photo of Halley did he show?

It would have been a ground based image (going on his response)

Doug

[Bob Shaw]

The only difference is the people who support the shuttle and/or the ISS are not scientists.
- Bob

And the people who pay for the things ain't either!

More's the pity...

Bob Shaw

[Bob Shaw]

In the absence of a dedicated LPSC thread, there's an interesting article in today's New Scientist (18 March 2006, p10):

A two page spread describes a rewriting of Mars geological time, with a new period - the Pre-Noachian - inferred from MOLA data indicating a new population of ancient large-scale cratering events which have been hidden beneath later impacts. "The early impact rate was quite a lot higher than we expected" according to Herb Frey of GSFC. The article also describes a turnaround in interpretations of crater rates in more modern eras, with most small craters now being seen as secondaries from a few larger events. One of the upshots of this is a suggested three-fold reduction in cratering rates in the last three billion years as compared to previous models.

And:

"The atmosphere that was

The atmosphere of Mars, which is so thin that on Earth it would be considered a hard vacuum, was once as thick or thicker than Earth's. At least that's the accepted theory, based on the abunndant evidence of river valleys on Mars's surface, suggesting that it must once have had air thick enough to support evaporation and rainfall. However, the idea has remained controversial.

Now a study of meteorites lends further support to the theory. John Bridges and Ian Wright of the Planetary and Space Sciences Research Institute at the Open University in Milton Keynes, UK, have found that the proportion of carbonates in some of the 32 known Mars meteorites found on earth suggest that the atmosphere originally contained carbon dioxide at pressures somewhere between 2.3 and 2.6 bars, compared with roughly 1 bar at sea level on Earth today.

The meteorites also reveal that by 670 million years ago the atmospheric pressure had come down to about 50 to 100 millibars and then fell further to today's level, which varies from virtually zero to 30 millibars depending on variations in the shape of Mars's orbit. Bridges and Wright presented the work at the lunar and Planetary sciences Conference in Houston, Texas."


Bob Shaw

[Guest_BruceMoomaw_*]

Michael Carr's excellent 1995 book "Water on Mars" cites the much greater erosion rate of craters on Noachian terrain -- not the existence of valley networks -- as proof of a dense Noachian atmosphere. Noachian terrain has far more big craters than Hesperian terrain; but most of its big craters are consistently eroded vastly more than the big ones you find in Hesperian terrain -- so much more as to suggest that the erosion rate was up to 1000 times higher in the Noachian. This indicates at least powerful wind erosion, regardless of whether or not Noachian Mars was also warm enough to have substantial amounts of fluvial erosion.

As for my reply on the funding of manned vs. unmanned space programs: it's coming.

[CosmicRocker]

I wasn't able to make it to that presentation Bob, but Golombek mentioned the secondary cratering in his paper on observations from Spirit's traverse in Gusev. He said that it has been observed that most of the craters there are relatively shallow compared to their width, and that is interpreted as evidence that they are secondary impacts from larger impacts elsewhere. He specifically mentioned Bonneville, Lahontan, and Searles, but said generally that most craters in Gusev were secondary.

The picture he painted of processes in Gusev since it was flooded with basalt was that it is essentially a sediment starved basin with little geologic activity, aside from the dust blowing around. When the secondary impacts occurred, the ejecta created temporary sources of sediment which was transported by the wind until it was eventually trapped in the bottoms of craters and other aeolian cul de sacs. After that, the only thing that occurs is the monotonous movement of dust until new secondary impacts again disrupt the equilibrium and create temporary sources of aeolian sediment. He mentioned sand ripples like Serpent and noted that they appear to be inactive, with surfaces armored with granule-sized clasts and dust depostited between the granules. However, someone else (forgot who) mentioned that El Dorado was thought to be active, since it's surface remains dark, while light colored dust is deposited around it. I'm not sure how convincing that is, though.

I'll try to post my notes from the other MER papers in appropriate topics in the MER section as time permits, unless people think it would be better to start a dedicated MER LPSC topic or a more general LPSC topic. I wasn't able to stay for anything other than the MER papers. I'd hate to post too much in here, since most who read the MER topics probably don't often look in here. Interesting about "the atmosphere that was." I hadn't heard about that.

[CosmicRocker]

Ok, I give up. I just read Emily's blog entry regarding the MER presentations. I don't know how she does it, because I wasn't able to take notes from these guys with as much detail as she has captured in her blog. She captured most everything I was going to post from Steve's and Matt's presentations, and more, and in pretty much their words, and while attending more sessions than I was able to attend! Everyone interested in the rovers really needs to read her notes. I think it's been obvious for a while, but Emily's blog has become _the_ blog to read for the latest summary of planetary news.

I was really sorry I could not stay to listen to Knauth's presentation. I could see the tension building up toward that in several of the previous presentations. It sounds as if I missed one of the most interesting confrontations of the entire conference. Although I was not able to stay for Knauth's presentation, my notes from Grotzinger's presentation contained several side comments to myself regarding how efficiently he blew away the basal surge hypothesis. I'm trying to keep an open mind, but I too must side with the MER team for now.

[Jyril]

It would have been a ground based image (going on his response)

Doug

If it was really a picture of halley, it must have been from 1910 given that it was the date of Halley's previous visit.

[Bob Shaw]

Interesting about "the atmosphere that was." I hadn't heard about that.

Yes - I posted it verbatim because the journalistic flim-flam was as dense as the putative ancient atmosphere! It beats me why NS at times published interesting snippets surrounded by mushy statements (yeah, right, Earth's atmospheric pressure is 1 bar, hey, news!). Perhaps the idea is to feed into the newspapers as a bit of publicity...

...anyway, I really didn't want to summarise an already over-summarised piece!

Bob Shaw

[Guest_BruceMoomaw_*]

Yep, it was a ground-based 1910 Halley photo.

I was really sorry I could not stay to listen to Knauth's presentation. I could see the tension building up toward that in several of the previous presentations. It sounds as if I missed one of the most interesting confrontations of the entire conference. Although I was not able to stay for Knauth's presentation, my notes from Grotzinger's presentation contained several side comments to myself regarding how efficiently he blew away the basal surge hypothesis. I'm trying to keep an open mind, but I too must side with the MER team for now.

Grotzinger's central argument against basal surge is nicely summed up in his abstract ( http://www.lpi.usra.edu/meetings/lpsc2006/pdf/2254.pdf ): "A further clue to the likely subaqueous origin
for Eagle cross-laminae is provided by their festoon geometry which requires that the reconstructed ripples have three-dimensional geometry defined by highly sinuous crestlines. In terrestrial settings such bedforms are known only to develop in subaqueous, subcritical flows, with velocities of less than one meter per second. They are not known to develop in eolian deposits or in subaerial base surge deposits." The italics are his.

[elakdawalla]

Yep, it was a ground-based 1910 Halley photo.
Grotzinger's central argument against basal surge is nicely summed up in his abstract ( http://www.lpi.usra.edu/meetings/lpsc2006/pdf/2254.pdf ): "A further clue to the likely subaqueous origin
for Eagle cross-laminae is provided by their festoon geometry which requires that the reconstructed ripples have three-dimensional geometry defined by highly sinuous crestlines. In terrestrial settings such bedforms are known only to develop in subaqueous, subcritical flows, with velocities of less than one meter per second. They are not known to develop in eolian deposits or in subaerial base surge deposits." The italics are his.

Knauth did show festoon structures that he said were the result of, I think, volcanic surge deposits. One of Grotzinger's (many) objections to his talk was that the scales of these things were an order of magnitude or so larger than the MArs ones. Knauth claimed in response that there are descriptions in the literature of smaller festoon structures in surge deposits but that they are not accompanied by pictures, and that he is working on obtaining pictures.

Sounds like a debate that won't die anytime soon.

--Emily

Ok, I give up. I just read Emily's blog entry regarding the MER presentations. I don't know how she does it, because I wasn't able to take notes from these guys with as much detail as she has captured in her blog. She captured most everything I was going to post from Steve's and Matt's presentations, and more, and in pretty much their words, and while attending more sessions than I was able to attend!

I type fast. Still, I'm sure you attended others of the MER talks -- I only got to go to those two and the Knauth one; I'd be delighted to see any notes you have from talks I didn't catch.

--Emily

[odave]

I second what CR said - you're doing a great job on your blog, Emily. Thanks for all of your hard work!

[Guest_BruceMoomaw_*]

Oh, yes.

I've got some comments on the LPSC abstracts related to the debate over basal surge, but I think I'll put them in a new topic in the "MER" section. (We're getting awfully snarled up, subject-wise, in a lot of the threads on this website -- thanks in large measure, admittedly, to me).

[nprev]

In the absence of a dedicated LPSC thread, there's an interesting article in today's New Scientist (18 March 2006, p10):

A two page spread describes a rewriting of Mars geological time, with a new period - the Pre-Noachian - inferred from MOLA data indicating a new population of ancient large-scale cratering events which have been hidden beneath later impacts. "The early impact rate was quite a lot higher than we expected" according to Herb Frey of GSFC. The article also describes a turnaround in interpretations of crater rates in more modern eras, with most small craters now being seen as secondaries from a few larger events. One of the upshots of this is a suggested three-fold reduction in cratering rates in the last three billion years as compared to previous models.

And:

"The atmosphere that was

The atmosphere of Mars, which is so thin that on Earth it would be considered a hard vacuum, was once as thick or thicker than Earth's. At least that's the accepted theory, based on the abunndant evidence of river valleys on Mars's surface, suggesting that it must once have had air thick enough to support evaporation and rainfall. However, the idea has remained controversial.

Now a study of meteorites lends further support to the theory. John Bridges and Ian Wright of the Planetary and Space Sciences Research Institute at the Open University in Milton Keynes, UK, have found that the proportion of carbonates in some of the 32 known Mars meteorites found on earth suggest that the atmosphere originally contained carbon dioxide at pressures somewhere between 2.3 and 2.6 bars, compared with roughly 1 bar at sea level on Earth today.

The meteorites also reveal that by 670 million years ago the atmospheric pressure had come down to about 50 to 100 millibars and then fell further to today's level, which varies from virtually zero to 30 millibars depending on variations in the shape of Mars's orbit. Bridges and Wright presented the work at the lunar and Planetary sciences Conference in Houston, Texas."
Bob Shaw

Wow. If accurate, then Mars had an atmosphere capable of sustaining liquid surface water until 670 my ago. Soft-bodied macrofauna had evolved on Earth by that time...

Have any Martian regions been identified with an age near this point? If so, we could do worse than to look at strata from this period for fossils.

[Guest_AlexBlackwell_*]

Wow. If accurate, then Mars had an atmosphere capable of sustaining liquid surface water until 670 my ago. Soft-bodied macrofauna had evolved on Earth by that time...

Have any Martian regions been identified with an age near this point? If so, we could do worse than to look at strata from this period for fossils.

The only "age" information comes from stratigraphic relationships, which are obscured by, among other things, depositional and exhumation events. And the chronostratigraphic systems themselves have variability depending on the authros. Aside from that, the error bars in these systems are huge; in fact, huge enough that I would suspect a 670 Myr point (or thereabouts) would not be temporally resolvable, though I guess it all depends on one's definition of "near this point." Obviously, what is needed is absolutely dating of martian samples, either in situ or returned.

The upshot is that I'd be highly skeptical of anyone pointing to a spot on Mars and saying it is 670 million years old, even if they added "plus or minus 50 million years."

[tty]

The only "age" information comes from stratigraphic relationships, which are obscured by, among other things, depositional and exhumation events. And the chronostratigraphic systems themselves have variability depending on the authros. Aside from that, the error bars in these systems are huge; in fact, huge enough that I would suspect a 670 Myr point (or thereabouts) would not be temporally resolvable, though I guess it all depends on one's definition of "near this point." Obviously, what is needed is absolutely dating of martian samples, either in situ or returned.

The upshot is that I'd be highly skeptical of anyone pointing to a spot on Mars and saying it is 670 million years old, even if they added "plus or minus 50 million years."

Wasn't that figure based on martian meteorites, for which we do have good absolute age determinations?

tty

[Phil Stooke]

"Wasn't that figure based on martian meteorites, for which we do have good absolute age determinations?"

- tty


We do have good dates for the martian meteorites... but we don't know which specific geologic units they came from. So they are no help in dating specific events in martian history. Only sample return from known locations or in situ dating (if that is ever possible) will allow that, and we will need dates from a lot of places to really tie down the history.

I know some suggestions have been made about which units - or at least regions - the meteorites come from, but nothing is firmly established.

Phil

[tty]

We do have good dates for the martian meteorites... but we don't know which specific geologic units they came from. So they are no help in dating specific events in martian history. Only sample return from known locations or in situ dating (if that is ever possible) will allow that, and we will need dates from a lot of places to really tie down the history.

I know some suggestions have been made about which units - or at least regions - the meteorites come from, but nothing is firmly established.

Phil

That date is presumably derived from the age of iddingsite in the Lafayette Nakhlite. As iddingsite is a mineral formed by water it does show that liquid water was present somewhere on Mars 670 MA ago.

tty

[Guest_AlexBlackwell_*]

Richard Kerr's LPSC coverage is in the March 31, 2006, issue of Science.