NASA Images Suggest Water Still Flows on Mars |
NASA Images Suggest Water Still Flows on Mars |
Guest_Sunspot_* |
Dec 4 2006, 09:25 PM
Post
#101
|
Guests |
Dec. 4, 2006
Dwayne Brown/Erica Hupp Headquarters, Washington 202-358-1726/1237 Guy Webster Jet Propulsion Laboratory, Pasadena, Calif. 818-354-6278 MEDIA ADVISORY: M06-186 NASA SCHEDULES BRIEFING TO ANNOUNCE SIGNIFICANT FIND ON MARS WASHINGTON - NASA hosts a news briefing at 1 p.m. EST, Wednesday, Dec. 6, to present new science results from the Mars Global Surveyor. The briefing will take place in the NASA Headquarters auditorium located at 300 E Street, S.W. in Washington and carried live on NASA Television and www.nasa.gov. The agency last week announced the spacecraft's mission may be at its end. Mars Global Surveyor has served the longest and been the most productive of any spacecraft ever sent to the red planet. Data gathered from the mission will continue to be analyzed by scientists. Panelists include: - Michael Meyer -- Lead Scientist, Mars Exploration Program, NASA Headquarters, Washington - Michael Malin -- President and Chief Scientist, Malin Space Science Systems, San Diego, Calif. - Kenneth Edgett -- Scientist, Malin Space Science Systems - Philip Christensen -- Professor, Arizona State University, Tempe, Ariz. |
|
|
Dec 12 2006, 08:09 PM
Post
#102
|
|
Senior Member Group: Members Posts: 2922 Joined: 14-February 06 From: Very close to the Pyrénées Mountains (France) Member No.: 682 |
I was "shoked" by M.Malin's assesment of the high probability of having a crater formed in your viscinity if you stay 20 years at the same spot. So, now, I wonder of the probabilty that a meteroid hit a "gully" zone and/or hit close enough that the effect will be to activate some gullies. Has this been already addressed or the probabilities are too remote to be considered?
-------------------- |
|
|
Guest_AlexBlackwell_* |
Dec 13 2006, 01:12 AM
Post
#103
|
Guests |
I was "shoked" by M.Malin's assesment of the high probability of having a crater formed in your viscinity if you stay 20 years at the same spot. So, now, I wonder of the probabilty that a meteroid hit a "gully" zone and/or hit close enough that the effect will be to activate some gullies. Has this been already addressed or the probabilities are too remote to be considered? I haven't read or heard anyone make a connection, direct or indirect, with impact events and gully activity, though some sort of seismic activity triggering the outbursts is very plausible. |
|
|
Dec 13 2006, 09:54 AM
Post
#104
|
|
Member Group: Members Posts: 593 Joined: 20-April 05 Member No.: 279 |
I haven't read or heard anyone make a connection, direct or indirect, with impact events and gully activity, though some sort of seismic activity triggering the outbursts is very plausible. But that wouldn't address the apparent issues of disparity between sunward/shadeward facing slopes. Andy |
|
|
Guest_AlexBlackwell_* |
Dec 13 2006, 04:11 PM
Post
#105
|
Guests |
But that wouldn't address the apparent issues of disparity between sunward/shadeward facing slopes. That's true, AndyG. And I should have been more precise in my reply. What I was driving at was that with only two apparent examples of recent (ca. 7 years) activity among the "thousands" of gullies, a non-insolation trigger might be plausible. I'm assuming, of course, that the putative near-surface reservoirs of liquid water do not vary temporally and spatially. |
|
|
Dec 15 2006, 06:47 PM
Post
#106
|
|
Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
That's true, AndyG. And I should have been more precise in my reply. What I was driving at was that with only two apparent examples of recent (ca. 7 years) activity among the "thousands" of gullies, a non-insolation trigger might be plausible. I'm assuming, of course, that the putative near-surface reservoirs of liquid water do not vary temporally and spatially. My long-standing suggestion here is that the sun-facing slopes don't form gullies because they would have already exhausted their reservoirs long ago, like short-period comets. In a nutshell, a gully can form when a slope experiences something close to a meteorological record high temperature plus other factors (a little more dustpack on top of the crater) add enough stress to break the camel's back. Seismic activity would have to be particularly well timed to have an effect. Note that certain fault systems on Earth are more likely to experience a seismic event depending upon the tides. But obviously the overwhelming majority of tidal events (every 13 hours) do not cause quakes. It just becomes the straw that (rarely) breaks the camel's back. Frozen rivers (such as the Nenena) break every spring when the ice melts. Presumably, a stick of dynamite well-placed on the day the ice was going to break anyway could speed the event by minutes or hours. But a stick of dynamite would not possibly cause it to break (riverwide) in January. |
|
|
Guest_AlexBlackwell_* |
Dec 15 2006, 06:56 PM
Post
#107
|
Guests |
Seismic activity would have to be particularly well timed to have an effect. An exogenic trigger for seismic activity (e.g., impact-induced) would, I agree, suffer from the dreaded "Tooth Fairy" hurdle, which I mentioned in another context. However, it's not too much of a stretch to posit that endogenic seismic activity, assuming it occurs on Mars, could trigger outbursts. And, again, the paucity of detectable activity among the tens of thousands of sites is not an insignificant issue. |
|
|
Lo-Fi Version | Time is now: 26th September 2024 - 01:35 PM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |