Greg K.
Reged: 12/11/03
Posts: 9971
Loc: Clifton Park, NY
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Pretty cool..
http://apod.nasa.gov/apod/ap080602.html
http://phoenix.lpl.arizona.edu/05_31_pr.php
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NexStar 11 GPS
Orion SkyView Pro 8EQ w/ Autostar
15x70 Celestron SkyMasters
Orion 90mm Mak
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LadyAstronomer
Bookworm
Reged: 11/15/07
Posts: 2951
Loc: Library of Congress
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Yes it is!!! 
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"I do not know what I may appear to the world, but to myself I seem to have been only a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me." -- Sir Isaac Newton
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Rick Woods
Post Laureate
Reged: 01/27/05
Posts: 4301
Loc: Inner Solar System
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I have a problem with the "objectives" blanket statement "Liquid water does not currently exist on the surface of Mars". It could quite possibly exist in some of the deeper locations, such as Hellas or Valles Marineris, where the atmospheric pressure approaches 20 millibars.
I firmly believe that indigenous life will eventually be found on Mars. Present and past.
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- Rick
14" LX200GPS
8" Meade 826C
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matt
Vendor (Scopemania)
Reged: 07/28/03
Posts: 10022
Loc: Chaville, France
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Looks like a baseball home plate to me...
I just wish they had not jumped so fast. Someone's gonna look pretty dumb if they find out it's just white rock.
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LivingNDixie
Lord of Ferrets
Reged: 04/23/03
Posts: 15790
Loc: Hoover, AL
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Quote:
I have a problem with the "objectives" blanket statement "Liquid water does not currently exist on the surface of Mars". It could quite possibly exist in some of the deeper locations, such as Hellas or Valles Marineris, where the atmospheric pressure approaches 20 millibars.
I firmly believe that indigenous life will eventually be found on Mars. Present and past.
Present life? Umm not buying that one. I will be surprised if they don't find past life though. It may take 20 years or more but I will be surprised if they don't find it.
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Preston
Celestron 11" Nexstar GPS XLT
Lunt LS60T/Ha 60mm f/8.33 (on order)
It’s not finishing something when your tank is empty that makes you a stronger person. It’s brushing yourself off and refacing the foe that defeated you with the same determination and willingness to fight that you had when you began your journey.
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Pess
(Title)
Reged: 09/12/07
Posts: 1910
Loc: Toledo, Ohio
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Quote:
Quote:
I have a problem with the "objectives" blanket statement "Liquid water does not currently exist on the surface of Mars". It could quite possibly exist in some of the deeper locations, such as Hellas or Valles Marineris, where the atmospheric pressure approaches 20 millibars.
I firmly believe that indigenous life will eventually be found on Mars. Present and past.
Present life? Umm not buying that one. I will be surprised if they don't find past life though. It may take 20 years or more but I will be surprised if they don't find it.
If there was past life there would almost have to be present life...evolution being what it is.
Mars may be a real inhospitable place as far as we are concerned but if it took millions of years to get to its present state then life had time to adapt to the changing situation.
That's what evolution does--new environmental stresses shape and adapt life forms...not the other way around.
That's why we have extremophiles on earth (But, then again, to an extremophile we are the extremophiles!)
If life never arose on mars in the first place, then that's another story.
Pesse (Life on Mars) Mist
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LadyAstronomer
Bookworm
Reged: 11/15/07
Posts: 2951
Loc: Library of Congress
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Quote:
I just wish they had not jumped so fast. Someone's gonna look pretty dumb if they find out it's just white rock.
The Phoenix (See Rick, I spelled it correctly!  ) team isn't saying it IS ice. They are saying at first glance it appears to be ice or more accurately, "our leading interpretation is ice."
The reason it looks white is most likely glare. Here is a closer view of what has been unearthed under the lander:
Snow Queen
Notice how smooth it is, the rounded cavities, the layering within the material itself. It presents the appearance of "dirty ice," and that's all the team is saying.
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"I do not know what I may appear to the world, but to myself I seem to have been only a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me." -- Sir Isaac Newton
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Joad
Wordsmith
Reged: 03/22/05
Posts: 11919
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I will be astonished if they don't find water ice; after all, there is water ice throughout the solar system and plenty of evidence for surficial liquid water in the past on Mars.
I won't speculate about life, however.
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jupiterzkool
Pooh-Bah
Reged: 05/08/06
Posts: 1341
Loc: Pasadena, CA
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The more likely candidate is CO2 (dry) ice, just on the basis of the fact that there is much more CO2 to condense out of the atmosphere. Water ice is much less likely.
-S
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Scott G. Edgington, Planetary Scientist
Cassini-Huygens: Mission to Saturn & Titan
Yes, Asia, John Wetton Fan
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 6782
Loc: Beatrice, Nebraska
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Quote:
I have a problem with the "objectives" blanket statement "Liquid water does not currently exist on the surface of Mars". It could quite possibly exist in some of the deeper locations, such as Hellas or Valles Marineris, where the atmospheric pressure approaches 20 millibars.
I firmly believe that indigenous life will eventually be found on Mars. Present and past.
For the most part, liquid water is not stable anywhere on the surface of the planet for more than perhaps brief intervals and in very small amounts. No clear indications of bodies of standing liquid water have been detected by the current set of orbiters, and none of the landers found evidence of liquid water currently on the planet as well. I have seen no figures supporting a pressure figure of 20 millibars anywhere on Mars, as the range tends to be in the six to 10 millibar range (Viking 2 reported a maximum pressure of around 10 millibars). There have been suggestions for theoretical maximum pressures as high as 12.4 millibars in certain parts of Hellas, but not much higher. Most of Valles Marineris is higher than the deepest parts of Hellas, so the pressures probably wouldn't be much better there. Even in these deep areas, the temperature would rarely be high enough for liquid water to exist. Thus, while the blanket statement may or may not be completely accurate, it isn't really very far off. Clear skies to you.
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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
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Rick Woods
Post Laureate
Reged: 01/27/05
Posts: 4301
Loc: Inner Solar System
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Quote:
Thus, while the blanket statement may or may not be completely accurate, it isn't really very far off.
But possibly just far enough...?
(I'll try to find my reference for the 20 millibar figure).
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- Rick
14" LX200GPS
8" Meade 826C
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jupiterzkool
Pooh-Bah
Reged: 05/08/06
Posts: 1341
Loc: Pasadena, CA
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I really do not understand how 10 millibar vs. 20 millibar makes a difference in regards to the presence of liquid water. The important thing is how much water vapor is in the air relative to the saturation vapor pressure water vapor over liquid water and water ice at these temperatures and pressures. I suspect that doubling the atmospheric pressure will have a very minor impact.
-S
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Scott G. Edgington, Planetary Scientist
Cassini-Huygens: Mission to Saturn & Titan
Yes, Asia, John Wetton Fan
Edited by jupiterzkool (06/03/08 04:08 PM)
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Rick Woods
Post Laureate
Reged: 01/27/05
Posts: 4301
Loc: Inner Solar System
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Only that technically, if the air pressure is over something like 6.2 millibars (I forget the exact number), liquid water could exist.
OK, OK, it's a slender thread. But still...
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- Rick
14" LX200GPS
8" Meade 826C
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jupiterzkool
Pooh-Bah
Reged: 05/08/06
Posts: 1341
Loc: Pasadena, CA
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Assuming a surface temperature of 200K at the surface of Mars, the vapor pressure of water over water ice is 0.00168 millibar and over liquid water is 0.00328 millibar. This indicates that any water vapor is likely to condense into ice first. While my references give a range of values for the observed abundance of water vapor at the surface of mars , they all report less than 0.0168 millibar of water vapor. Thus aside from t he possibility of thin water ice clouds in the atmosphere, I would expect neither ice or liquid water at the surface unless the temperature is colder than 200K.
-S
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Scott G. Edgington, Planetary Scientist
Cassini-Huygens: Mission to Saturn & Titan
Yes, Asia, John Wetton Fan
Edited by jupiterzkool (06/03/08 08:18 PM)
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 6782
Loc: Beatrice, Nebraska
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Quote:
Only that technically, if the air pressure is over something like 6.2 millibars (I forget the exact number), liquid water could exist.
OK, OK, it's a slender thread. But still...
Well, all hopes aside for the moment, one thing to look at is what temperatures and pressures are possible. The "triple point" of water is 6.1173 millibars and a temperature of 273.16 K. At that pressure/temperature point, water can exist as a solid, a liquid, or a gas. The temperature on Mars only very rarely gets as high as the triple point temperature for water (Pathfinder recorded the highest temperature of 263 K). Thus, most of the stable water on the surface of Mars would have to be in the form of ice. Indeed, the *average* surface pressure on Mars is pretty close to 6.1 millibars, so for the most part, if any liquid water were to form, sadly, it would probably boil away after a short period of time. Even at a pressure of 12.4 millibars, the boiling temperature of water is only about 10 degrees above the triple point, or about 10 C, so it can't get very warm in Hellas before any liquid water would also boil away. All this makes for a very narrow range of conditions, and locations on Mars where liquid water might be able to exist, and even then, it would probably not be liquid for a long period of time. Clear skies to you.
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StarWars
Postmaster
Reged: 11/26/03
Posts: 11634
Loc: At The Movies
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The JPL boys hit the nail on the head...again.. 
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Sony Digital Media player..
MX 460 earbuds
15x70 ETX125AT
FireBall XL5
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moynihan
Carpal Tunnel
Reged: 07/22/03
Posts: 1517
Loc: Wisconsin
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Cool!
Hope it is water ice, but will be interesting to find out whatever it is.
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"Gosh, you've... really got some nice toys here"
Dual mount/ambient temperature Hominid Widefield Photon Collectors®
Pleistocene™ ½ watt Wetware Integration Unit.
entia non sunt multiplicanda praeter necessitatem
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Remy Bosio
Zeit-Meister
Reged: 03/02/04
Posts: 8325
Loc: Kenner, LA.
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Looks like just a white rock to me!
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REMY
Meade ETX 125PE
Sears Discoverer 60mm.
15X70(Obie),7X35,7X50,10X25
Canon XT (350D)
Oly C750uz
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"Life Member" Pontchartrain Ast. Soc. Inc.
http://pasnola.org/
"Pay no attention to that man behind the curtain!"
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StarWars
Postmaster
Reged: 11/26/03
Posts: 11634
Loc: At The Movies
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Quote:
Looks like just a white rock to me!
SALT... 
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Sony Digital Media player..
MX 460 earbuds
15x70 ETX125AT
FireBall XL5
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