# Where did the Martian water go? **URL:** \ **Category:** Factual Questions\ **Created:** [March 25, 2004, 6:02pm UTC](https://boards.straightdope.com/t/where-did-the-martian-water-go/236384 "2004-03-25T18:02:35Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![kelly5078](https://avatars.discourse-cdn.com/v4/letter/k/6f9a4e/32.png) [@kelly5078](https://boards.straightdope.com/u/kelly5078)\ **Post date:** [March 25, 2004, 6:02pm UTC](https://boards.straightdope.com/t/where-did-the-martian-water-go/236384/1 "2004-03-25T18:02:35Z")
I keep reading articles about evidence for vast amounts of liquid water formerly existing on Mars. But when it comes to the question of where the water might have gone … silence. It seems to me that there are only a few possibilities: - Evaporation/sublimation followed by escape into space; - Incorporation in hydrated minerals, which probably couldn’t account for much; - Former surface water has become groundwater (or ice), but I should think that a the Martian aquifers would have been as fully charged while there was surface water. It seems like the first alternative makes the most sense, but none of them really feel right. Of course, I’m only used to planets with a pronounced geothermal gradient, a dense, oxygen-rich atmosphere, and abundant life, so maybe my imagination is limited. Any ideas? ---
**Author:** ![Eve](https://avatars.discourse-cdn.com/v4/letter/e/9e8a1a/32.png) [@Eve](https://boards.straightdope.com/u/Eve)\ **Post date:** [March 25, 2004, 6:29pm UTC](https://boards.straightdope.com/t/where-did-the-martian-water-go/236384/2 "2004-03-25T18:29:28Z")
Where did Martian water go? Long time passing? Where did Martian water go? Long, long time ago? Where did Martian water go? [Gone to vapor](http://news.bbc.co.uk/1/hi/sci/tech/2546923.stm), every one. When will they ever learn? When will they ever learn . . . ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [March 25, 2004, 6:36pm UTC](https://boards.straightdope.com/t/where-did-the-martian-water-go/236384/3 "2004-03-25T18:36:45Z")
To expand on the evaporation bit, eventually the water vapour reaches a point where it can be photodissociated by sunlight. The hydrogen then escapes into space leaving the oxygen looking for a home. You wind up with lots and lots of oxides on the surface. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [March 25, 2004, 6:44pm UTC](https://boards.straightdope.com/t/where-did-the-martian-water-go/236384/4 "2004-03-25T18:44:36Z")
[Here it is.](http://marsrovers.jpl.nasa.gov/gallery/all/2/m/079/2M133386588EFF2232P2957M2M1.HTML) ---
**Author:** ![ice1000](https://avatars.discourse-cdn.com/v4/letter/i/a3d4f5/32.png) [@ice1000](https://boards.straightdope.com/u/ice1000)\ **Post date:** [March 26, 2004, 5:16am UTC](https://boards.straightdope.com/t/where-did-the-martian-water-go/236384/5 "2004-03-26T05:16:12Z")
The thing that confuses me is that how could there be a salty ocean (or any liquid water)in Mars? Wouldn’t it have been frozen, given the distance it is from the sun? ---
**Author:** ![ITR\_champion](https://avatars.discourse-cdn.com/v4/letter/i/c67d28/32.png) [@ITR\_champion](https://boards.straightdope.com/u/ITR_champion)\ **Post date:** [March 26, 2004, 6:00am UTC](https://boards.straightdope.com/t/where-did-the-martian-water-go/236384/6 "2004-03-26T06:00:24Z")
I think scientists are still debating whether the contents and density of the Martian atmoshpere were the same in the past as they are now. Distance from the sun is not the only factor that affects temperature. A significant amount of carbon dioxide would create a greenhouse effect that could raise the surface temperature of Mars enough to allow liquid water throughout the day.