Confirmation of ancient lake and current lightning on Mars

Two very interesting reports from yesterday:

[link]
[link]

The old shorelines are in Shalbatana Vallis:

"Estimated to be more than 3 billion years old, the lake appears to have covered as much as 80 square miles and was up to 1,500 feet deep -- roughly the equivalent of Lake Champlain bordering the United States and Canada, said CU-Boulder Research Associate Gaetano Di Achille, who led the study. The shoreline evidence, found along a broad delta, included a series of alternating ridges and troughs thought to be surviving remnants of beach deposits.

"This is the first unambiguous evidence of shorelines on the surface of Mars," said Di Achille. "The identification of the shorelines and accompanying geological evidence allows us to calculate the size and volume of the lake, which appears to have formed about 3.4 billion years ago."

The "huge and sudden" bursts of dry lightning are in large dust storms:

"What we saw on Mars was a series of huge and sudden electrical discharges caused by a large dust storm," Ruf said. "Clearly, there was no rain associated with the electrical discharges on Mars. However, the implied possibilities are exciting."

Paul

Oops, the first link should be:

[link]

Paul

Thanks for the find on Shalbatana Lake Paul. It will be intersting to see their analysis in support of the conclusions but the find certainly provides further evidence of an earlier warmer, wetter Mars, and by inference, supports the Playsa/groundwater recharge model for Meridiani. In comparing the water driven/impact surge arguments for early Mars/Meridiani I have reached the conclusion that the water driven model is supported by clear evidence both from orbit and on the ground whereas the impact surge concept is more broad brush and arm waving.

The "amnesia" that Spirit suffered somewhat recently might have been due to being struck by an electrical discharge associated with the dust devils.

Thanks for the links Paul!
This is what Dana and me been talking about in this topic
I am glad others looking closely at the HiRISE imaging as well
Actualy there is lots more of this kind of evidence visible all around in HiRISE closeups - we just have to look.

The ligntning evidence is interesting as well, maybe Barsoomer is right and such ligntning discharge struck Spirit rercently causing computer hardware problems.

MPJ - I have tried to fight my way through Dana's rather difficult writing style but the linked page seems to imply current water effects as opposed to the evidence of an ancient lake that remained for a considerable period billions of years ago then disappeared very quickly due to a sudden climate change?

serpens, your right the above topic started by Dana is about more recent evidence of water (or other liquid) activity (which is my favourite theme btw) but not realy keeping the focus, we discussed similar things like the CU researcher in their paper.

Example from the later topic (image 250 m across):

This closeup of a Sirenum Fossae circular depression (crater?) shows clear signs of a former waterlevel (shoreline)IMO - time scale, I dont know.

MPJ There is most likely a change in lithology at the boundary you show but this in itself is weak evidence for a former shoreline.

Hi Ben, this shoreline like change in lithology is visible all around the boundaries of this depression at the same elevation so the most easy way for me as a non geologist and those amateur is to suspect a former water table to form this. The single instance of waterlevel indication (opposed to multiple waterlevels cause of slowly vanishing water) is also easily explained by a visible massive breach to the east which could have drained all the water from this depression quite fast when it appeared (maybe impact?) - so not nessesarily a sudden change in climate here but a simple outflow after some time of standing water - if it been a standing pool of water after all.

here's the article: http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1939.pdf

Interesting article - i wonder if there is HiRISE data available from the western and northern part of the MEX context view referenced in this article.

If they are right this could be part of the ancient bottom or near shoreline area of this paleolake:

http://hirise.lpl.arizona.edu/PSP_009683_1830

100% Zoom, 180° rotated RGB strip upper part (North)

As of their MEX context image drawing of the possible shoreline this area should have been submerged - yet it somehow looks a little like rocky shoreline features as well - maybe the lake been quite shallow here with parts of the morphology been above waterlevel most of the time.

I have not posted here in a while.
We hear reports about finding evidence of ancient lakes and water on Mars constantly. And each time, it is portrayed as if this is some amazing new discovery.

http://www.usatoday.com/tech/science/space/2004-09-09-mars-water-study_x.htm

Stan

Hi Stan.
While there has been a weight of evidence of lakes and possibly a northern ocean on Mars for some time this has been countered by arguments of substance by the white Mars and impact surge proponents. While Shalbatana Vallis was always attributed to water effects this latest research shows a clear shoreline and other compelling evidence. The paper is here:

http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1939.pdf

Current water activity, with the possible exception of a few crater gulleys which may or may not be due to liquid, seems neither evident not possible.

Hi Stan.
While there has been a weight of evidence of lakes and possibly a northern ocean on Mars for some time this has been countered by arguments of substance by the white Mars and impact surge proponents. While Shalbatana Vallis was always attributed to water effects this latest research shows a clear shoreline and other compelling evidence. The paper is here:

http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1939.pdf

Current water activity, with the possible exception of a few crater gulleys which may or may not be due to liquid, seems neither evident not possible.

@Sten: Yup i agree. Remember the frozen lake (North Sea size) evidence back in 2005:
http://news.bbc.co.uk/2/hi/science/nature/4285119.stm
If there are no other geoligical processes which create flat, pack ice like surfaces its quite clear what MEX imaged there.

@Serpens: I wouldnt bet high on this kind of assumptions.
With our current theoretical knowledge of Mars even liquid water is possible there now and then. There are areas with atmospheric pressures well above the sublimation point of water, there are temperatures as high as 30° C, there could be salty brines with freezing points down to -70° C and the most important: there is water ice/frost all around.