The MECA story, A place for speculation |
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The MECA story, A place for speculation |
 Aug 5 2008, 07:21 PM
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#271
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Member  Group: Members Posts: 910 Joined: 4-September 06 From: Boston Member No.: 1102  |
QUOTE (ugordan @ Aug 5 2008, 03:12 PM)  The fact we find all kinds of extremophiles on Earth doesn't say much as life probably didn't evolve in such harsh conditions in the first place. I think there is still a lot of discussion about what conditions were like when live evolved (or came in on a rock) here on earth. Many evolutionary biologists think conditions were fairly extreme (near 100 C) and extremophiles were the early norm. -------------------- |
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Aug 5 2008, 07:22 PM
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#272
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 Senior Member Group: Members Posts: 2173 Joined: 28-December 04 From: Florida, USA Member No.: 132 |
QUOTE (CosmicRocker @ Aug 5 2008, 03:20 PM) I really wanted to learn was the concentration of the ClO4-. Did anyone mention the concentration, or did anyone even ask what it was? It was asked a couple times.... no answer yet. More data and/or analysis required. |
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Aug 5 2008, 07:31 PM
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#273
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 Senior Member Group: Moderator Posts: 3233 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
QUOTE (Floyd @ Aug 5 2008, 12:21 PM) I think there is still a lot of discussion about what conditions were like when live evolved (or came in on a rock) here on earth. Many evolutionary biologists think conditions were fairly extreme (near 100 C) and extremophiles were the early norm. True, but the sentiments of ugordan's post ring true. We should be cautious about using the range of conditions that life exists on Earth today to predict whether there is life in the extreme environments seen elsewhere in the solar system. Evolution is a powerful process. -------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
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Aug 5 2008, 07:32 PM
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#274
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 Senior Member Group: Members Posts: 1465 Joined: 9-February 04 From: Columbus OH USA Member No.: 13 |
In case someone wants to hear the telecon before the audio is posted on the JPL website, here's an MP3 I made (thx Audacity):
Phoenix telecon, Aug. 8, 2008 (14MB mp3 file) -------------------- |
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Aug 5 2008, 07:42 PM
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#275
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Junior Member Group: Members Posts: 59 Joined: 4-July 08 Member No.: 4251 |
Outstanding, thank you!
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Aug 5 2008, 07:42 PM
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#276
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Newbie Group: Members Posts: 4 Joined: 4-August 08 Member No.: 4291 |
QUOTE (volcanopele @ Aug 5 2008, 09:31 PM) True, but the sentiments of ugordan's post ring true. We should be cautious about using the range of conditions that life exists on Earth today to predict whether there is life in the extreme environments seen elsewhere in the solar system. Evolution is a powerful process. The Earth is our only source of comparison - we're grasping at straws in exobiology, so we may as well as well grasp at the most familiar straws. QUOTE (jmknapp @ Aug 5 2008, 09:32 PM) In case someone wants to hear the telecon before the audio is posted on the JPL website, here's an MP3 I made (thx Audacity): Phoenix telecon, Aug. 8, 2008 (14MB mp3 file) Very useful, thank you. |
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Aug 5 2008, 07:44 PM
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#277
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 Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
@jmknapp: you are awesome. My voice recorder's batteries died about 10 minutes in to the conference.
Here's one of my two questions that I didn't get to ask, responded to very very quickly via email (thanks Sara!) -- I thought this would be of interest to you all. QUOTE > For Bill Boynton: I was surprised to hear that TEGA needed to be > programmed to look for chlorine. My (admittedly very rudimentary) > understanding of mass spectrometers is that you were reading a > continuous spectrum of masses of species driven off during your > heating cycles. Are you actually reading a discontinuous spectrum, or > even just looking at discrete masses along the spectrum? We can operate TEGA in two different modes. In one mode we can scan all the masses, in which case we would see chlorine had it been there. But it takes about 5 minutes to complete a full scan at a good sensitivity level. The way we operate TEGA when we are heating the sample, we select several (generally 10 to 20) masses of interest and continuously jump back and forth between them so we don't waste time on masses that we don't think will be of interest. We do occasionally run a full mass scan, but normally during heating, it is just the mass hopping mode. --Emily -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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| Guest_Sunspot_* |
Aug 5 2008, 07:52 PM
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#278
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Guests |
I wonder what would happen to NASA's Mars exploration program if a test on a current or future mission definitively and positively ruled out life ever having existed there.
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Aug 5 2008, 08:00 PM
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#279
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 Member Group: Members Posts: 813 Joined: 29-December 05 From: NE Oh, USA Member No.: 627 |
QUOTE (Sunspot @ Aug 5 2008, 03:52 PM) I wonder what would happen to NASA's Mars exploration program if a test on a current or future mission definitively and positively ruled out life ever having existed there. Don't think there is any single test that could say that. We are talking an entire world here, as much land area as Earth and all that underground territory. Craig |
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Aug 5 2008, 08:05 PM
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#280
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 The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
I don't think that scenario could ever develop, to be honest. Mars is a huge place, with many, many different environments to check for forms of life. It wouldn't be possible to ever declare "No life here!" unless they'd looked under or inside every rock, checked beneath all the ice layers, searched every low-lying valley, etc. Life could exist in aquifers deep underground, or inside volcanic vents, or countless other places, in theory.
But if Mars was ever declared officially dead then maybe it would actually spur on exploration and exploitation; with no native life to protect, it would be a case of unload the bulldozers and get digging guys..! 
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Aug 5 2008, 08:07 PM
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#281
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 Special Cookie Group: Members Posts: 2168 Joined: 6-April 05 From: Sintra | Portugal Member No.: 228 |
QUOTE (Stu @ Aug 5 2008, 09:05 PM) But if Mars was ever declared officially dead then maybe it would actually spur on exploration and exploitation; with no native life to protect, it would be a case of unload the bulldozers and get digging guys..! I actually have a shovel... -------------------- "Ride, boldly ride," The shade replied, "If you seek for Eldorado!"
Edgar Alan Poe |
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Aug 5 2008, 08:12 PM
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#282
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
... yeah, and you'd just dig and dig and dig with it until you'd finally MADE an abyss...!
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Aug 5 2008, 08:13 PM
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#283
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Special Cookie Group: Members Posts: 2168 Joined: 6-April 05 From: Sintra | Portugal Member No.: 228 |
A perchlorate-free abyss I presume...
-------------------- "Ride, boldly ride," The shade replied, "If you seek for Eldorado!"
Edgar Alan Poe |
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Aug 5 2008, 08:24 PM
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#284
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Senior Member Group: Members Posts: 2173 Joined: 28-December 04 From: Florida, USA Member No.: 132 |
QUOTE (volcanopele @ Aug 5 2008, 03:31 PM) We should be cautious about using the range of conditions that life exists on Earth today to predict whether there is life in the extreme environments seen elsewhere in the solar system. Evolution is a powerful process. Yes, evolution would be a powerful process anywhere, and if life had ever existed on Mars it could well have evolved to keep pace with changing conditions. |
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Aug 5 2008, 08:40 PM
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#285
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 Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
QUOTE (centsworth_II @ Aug 5 2008, 12:24 PM) Yes, evolution would be a powerful process anywhere, and if life had ever existed on Mars it could well have evolved to keep pace with changing conditions. ...or the conditions were radically different chemically at the start even from Earth's primordial environment in the first place, and anything that still might be living on Mars would find the current environment just peachy-keen. It's a complete data hole. We have no idea whatsoever even what the grossest constraints on the origin of life might be, except for the fact that it does seem that liquid water is needed for a time. Any other general assumption just doesn't seem supportable; there are too many possibilities. Stu is right. It'll take 1000 years or more of detailed exploration to answer the very basic question of yes or no to life on Mars if we don't get exceedingly lucky. We haven't gotten exceedingly lucky in this regard yet. Carl Sagan's famous principle "Absence of evidence is not evidence of absence" has never been more true then it is for this issue. -------------------- 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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