August 29, 2007, HiRISE release |
August 29, 2007, HiRISE release |
Guest_AlexBlackwell_* |
Aug 29 2007, 07:15 PM
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#1
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August 29, 2007, HiRISE release
Interesting new image of the Arsia Mons pit. The polar pit gullies image is pretty good, too. |
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Aug 29 2007, 08:31 PM
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#2
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Member Group: Members Posts: 160 Joined: 4-July 05 From: Huntington Beach, CA, USA Member No.: 429 |
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Guest_AlexBlackwell_* |
Aug 29 2007, 08:34 PM
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#3
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Guests |
The structure of the wall is fascinating.
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Aug 29 2007, 08:39 PM
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#4
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Founder Group: Chairman Posts: 14434 Joined: 8-February 04 Member No.: 1 |
Big enough to get a few CRISM pixels in there
Doug |
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Aug 29 2007, 09:09 PM
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#5
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Senior Member Group: Admin Posts: 4763 Joined: 15-March 05 From: Glendale, AZ Member No.: 197 |
-------------------- If Occam had heard my theory, things would be very different now.
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Guest_AlexBlackwell_* |
Aug 29 2007, 11:00 PM
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#6
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Guests |
Here's a related press release:
HiRISE Camera Returns New View of Dark Pit on Mars UA News August 29, 2007 |
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Aug 30 2007, 02:38 AM
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#7
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Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
You know, it's really interesting and cool to look into such a Martian pit. But, guys -- it's all basalt. Garden-variety basalt. You can look at the exact same kind of rock all over the Earth, and if you want to get some from off-Earth, there's a quadrillion tons more just 400,000 km away...
In other words, while the feature really looks interesting, it doesn't tell the story about Mars that I want to hear. The rock beds I want to see a sharp cut through are a lot older than this stuff. -the other Doug -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Aug 30 2007, 07:25 PM
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#8
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Member Group: Members Posts: 259 Joined: 23-January 05 From: Seattle, WA Member No.: 156 |
Sense of wonder, other Doug! Sense of wonder! Doesn't the thought of kilometers-long, tens of meters-high Martian caverns still your breath for just a tiny bit?
And I do wonder at the potential of Martian caverns as ecosystems. Yeah, they'd be cold, but the temperature would be stable, which counts for something; there'd be none of that pesky UV and less of those nasty superoxides. While I am inclined to agree that the action's in the really ancient rocks, I have to wonder - might there be lava tubes at the sites of recent eruptions involving water? What might they hold? |
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Aug 30 2007, 11:27 PM
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#9
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Member Group: Members Posts: 813 Joined: 29-December 05 From: NE Oh, USA Member No.: 627 |
Sense of wonder, other Doug! Sense of wonder! Sense of wonder, indeed. Being of the generation that remembers Mariner 4, these images just blow me away. Mariner 4 laid to rest the Lowelian Barsoom. There were reputable scientists at that time who just wrote Mars off as nothing but another Luna with a wisp of air. "Mars is Dead" proclaimed the NYT. Mariner 4 killed the fantasy, but in place of that, gave us a real world. And that world just gets more complex with each added mission. Look at the HRISE south pole spider imaging. Is this "just" a vertical shaft into the basalt, or a doorway into a nether realm of caverns (fantasy again... or not). Let's find out, and not just write it off. Craig |
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Aug 31 2007, 03:24 AM
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#10
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Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
Oh, trust me, I'd be first in line if they were asking for volunteers to go spelunking down into that hole. As far as sense of wonder, and also human-habitable volumes, are concerned, the place is a wonder. And I don't write it off as being *completely* uninteresting from a geological point of view.
But, hey -- if Steve Squyres can write about (paraphrasing here) "nothing but boring, uninteresting chunks of lava as far as the eye can see" about the floor of Gusev, I figure I've at least a little support for the idea that the real action truly is in the much older rocks. I do admit, though, that Martian caverns would be the perfect places for medium-term and long-term human habitats. Their interiors are protected from solar and cosmic radiation (a very important consideration), and the application of enough heat (plus a little Yankee building ingenuity) could seal up cavern walls and allow a section of a cavern to be pressurized with a livable atmosphere. Heck, with enough native water, you might even be able to make indigenous concrete... -the other Doug -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Aug 31 2007, 04:33 AM
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#11
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Just on the principle of dropping a rock into a mineshaft & counting the seconds until you hear the echo, would LOVE to do a precision ranging radar/lidar pass over these holes for even an approximate depth estimation...wouldn't it be interesting if some were deep enough to have estimated bottom atmospheric pressures >= 20mb, which IIRC is the minimum threshold for maintaining liquid water at average Martian equatorial temps...
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Aug 31 2007, 10:14 AM
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#12
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Member Group: Members Posts: 593 Joined: 20-April 05 Member No.: 279 |
20mb would occur at a depth of about 12 kilometres below the Mars nominal "sea level".
Your rock needs to fall for about 80 seconds. Andy, neglecting air resistance, as is traditional. |
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Aug 31 2007, 10:16 AM
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#13
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Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
Unfortunately, most of the pits which may lead into lava tubes are located on the flanks of Tharsis volcanic piles, which are located significantly higher than median. Even if these "caverns" bottomed out a km below the local surface, they would be higher above the median than, say, is the floor of Hellas. So, unless there is some other mechanism concentrating the atmosphere, I can't see how it would be significantly higher in pressure down in these tubes than we see at, say, Meridiani.
-the other Doug -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Aug 31 2007, 11:52 AM
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#14
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
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Aug 31 2007, 11:54 PM
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#15
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Member Group: Members Posts: 428 Joined: 21-August 06 From: Northern Virginia Member No.: 1062 |
I barely noticed this picture myself, sometimes I miss the days of working with HiRISE and finding out about all of this a week and a half before the general public. Still, I do occasionally get to glimpse at things from a HiRISE perspective, it does help to have worked there.
It does indeed seem to be fairly near straight down. One thing that makes this unusual as compared to Earth is it's large size, I believe this is much larger than anything found on Earth. |
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