# Water flow on Mars? **URL:** \ **Category:** Factual Questions\ **Created:** [December 10, 2006, 5:51am UTC](https://boards.straightdope.com/t/water-flow-on-mars/383543 "2006-12-10T05:51:46Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Oslo\_Ostragoth](https://avatars.discourse-cdn.com/v4/letter/o/a9a28c/32.png) [@Oslo\_Ostragoth](https://boards.straightdope.com/u/Oslo_Ostragoth)\ **Post date:** [December 10, 2006, 5:51am UTC](https://boards.straightdope.com/t/water-flow-on-mars/383543/1 "2006-12-10T05:51:46Z")
Apparently recently proven. Is there already a thread on this? If so, please direct me to it and kill this one. If not, please discuss. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [December 10, 2006, 6:35am UTC](https://boards.straightdope.com/t/water-flow-on-mars/383543/2 "2006-12-10T06:35:55Z")
Looks pretty likely, so far. No definite confirmation yet, though. I found [this](http://www.hindu.com/thehindu/holnus/008200612091240.htm) article, which says, in part: > [@](#): > > A press release from EurekAlert says the presence of flowing liquid water at the surface demonstrates that Mars has an active hydrologic cycle that includes significant water exchange between the subsurface and the surface, Sumner said. > > "Even though liquid water is only transiently at the surface, it probably provided some water vapor to the atmosphere through evaporation and may have produced hydrous salts in surface sediments. Such hydrous sulfate salts have been inferred to be present at both MER rover sites, with the sedimentary rocks observed by Opportunity at Meridiani Planum containing more than 50% sulfates. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [December 10, 2006, 6:42am UTC](https://boards.straightdope.com/t/water-flow-on-mars/383543/3 "2006-12-10T06:42:04Z")
If the rovers drove by a puddle or a small stream would it even notice it? ---
**Author:** ![Oslo\_Ostragoth](https://avatars.discourse-cdn.com/v4/letter/o/a9a28c/32.png) [@Oslo\_Ostragoth](https://boards.straightdope.com/u/Oslo_Ostragoth)\ **Post date:** [December 11, 2006, 12:18am UTC](https://boards.straightdope.com/t/water-flow-on-mars/383543/4 "2006-12-11T00:18:37Z")
Actually, what I was referring to was some satellite imagery taken years apart that apparently show some kind of erosion differences/channeling. Story [here](http://www.cbsnews.com/stories/2006/12/07/ap/national/mainD8LS25800.shtml). More [here](http://news.google.com/news?hl=en&q=mars%20water&btnG=Google+Search&ie=UTF-8&oe=UTF-8&sa=N&tab=in). ---
**Author:** ![Alive\_At\_Both\_Ends](https://avatars.discourse-cdn.com/v4/letter/a/73ab20/32.png) [@Alive\_At\_Both\_Ends](https://boards.straightdope.com/u/Alive_At_Both_Ends)\ **Post date:** [December 11, 2006, 1:18am UTC](https://boards.straightdope.com/t/water-flow-on-mars/383543/5 "2006-12-11T01:18:26Z")
Given the very low air pressure on Mars, (about 6 millibars IIRC), could water exist in liquid form? Wouldn’t it boil away, even at Martian surface temperatures? ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [December 11, 2006, 1:46am UTC](https://boards.straightdope.com/t/water-flow-on-mars/383543/6 "2006-12-11T01:46:12Z")
[QUOTE=Oslo Ostragoth] Is there already a thread on this? [/QUOTE] There’s some discussion over in MPSIMS: [Water on Mars? Hip hip hooray! Really…](http://boards.straightdope.com/sdmb/showthread.php?t=399136) Much more detail at Bad Astronomy: [NASA To Announce Major ‘Find’ On Mars](http://www.bautforum.com/showthread.php?t=50335) [QUOTE=Alive At Both Ends] Given the very low air pressure on Mars, (about 6 millibars IIRC), could water exist in liquid form? [/QUOTE] The [pressure gets up to 10 millibars or so in the summer](http://science.nasa.gov/headlines/y2003/07aug_southpole.htm), when the southern CO[sub]2[/sub] cap has sublimed; possibly higher in some spots. It also gets warm enough that salty liquid water might last for a while on the surface. ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [December 12, 2006, 10:23pm UTC](https://boards.straightdope.com/t/water-flow-on-mars/383543/7 "2006-12-12T22:23:05Z")
The side-by-side comparison photos on the Dec 12th Astronomy Picture of the Day website ([http://antwrp.gsfc.nasa.gov/apod/](http://antwrp.gsfc.nasa.gov/apod/)) make it very clear what all the excitement is all about. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [December 12, 2006, 11:56pm UTC](https://boards.straightdope.com/t/water-flow-on-mars/383543/8 "2006-12-12T23:56:35Z")
[ur=http://www.theonion.com/content/node/54360]In related news . . . ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [December 12, 2006, 11:58pm UTC](https://boards.straightdope.com/t/water-flow-on-mars/383543/9 "2006-12-12T23:58:51Z")
[urk](http://www.theonion.com/content/node/54360) ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [December 18, 2006, 5:03pm UTC](https://boards.straightdope.com/t/water-flow-on-mars/383543/10 "2006-12-18T17:03:49Z")
Does anyone theorize that Mars in the past might have had a thicker atmosphere? Thick enough, maybe, to produce a greenhouse effect and higher surface temperature, so liquid water on the surface would be more plausible? ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [December 18, 2006, 5:35pm UTC](https://boards.straightdope.com/t/water-flow-on-mars/383543/11 "2006-12-18T17:35:24Z")
There’s conflicting theories on this, with some people thinking that it might have only been for a brief period early in Mars’s life, while others think that it might have persisted for a longer period of time. Personally, I think that the folks who believe that Mars has spent most of it’s life cold and dry are correct, and that the “wet” Mars folks are victims of wishful thinking. ---
**Author:** ![Diceman](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Diceman](https://boards.straightdope.com/u/Diceman)\ **Post date:** [December 18, 2006, 5:58pm UTC](https://boards.straightdope.com/t/water-flow-on-mars/383543/12 "2006-12-18T17:58:40Z")
[QUOTE=Tuckerfan] Personally, I think that the folks who believe that Mars has spent most of it’s life cold and dry are correct, and that the “wet” Mars folks are victims of wishful thinking. [/QUOTE] Having finally seen the pictures (thanks to the above link) I’m starting to come around to this conclusion. _That_ is the evidence of water flow?! :dubious: If you asked me, I’d say it looks like a landslide or rockfall. Sure, it might have been caused by water, but I sure as heck wouldn’t be willing to stand up and a soapbox and scream “WE’VE FOUND WATER !!!” at the top of my lungs.