Even More Water Beneath Mars' Surface?

[centsworth_II]

I'm confused. Remote sensing from Mars orbit has given an increasingly detailed picture of subsurface water on Mars. My major concern was the extent to which liquid water could be distinguished from ice in the data. Now, according to this article, a large portion of Mars' water may not be in the form of water <i>or</i> ice: <br /><br /><i>"Epsom-like salts believed to be common on Mars may be a major source of water there.... 'The Mars Odyssey orbiter recently showed that there may be as much as 10 percent water hidden in the Martian near-surface,' said David Bish....'We were able to show that under Mars-like conditions, magnesium sulfate salts can contain a great deal of water.' "</i><br /><br />Would any water held in the salts as described in the article be <b>in addition</b> to the water already detected? Or is this water included in the data already collected, meaning the amount held in salts reflects a reduction in the amount of water previously though to exist as liquid or ice? <br /><br />The impression I get from the article is that the salt-bound water is not detected by the instruments searching for liquid water and ice and would indeed represent an increase in the over-all estimate of total water on Mars. <div class="Discussion_UserSignature"> </div>

 

[fangsheath]

I believe these geologists are suggesting that some or all of the hydrogen signature discovered by Mars Odyssey outside the polar regions could be due to hydrated minerals such as epsomite or kieserite. I don't think they are suggesting that Odyssey has missed near-surface water in this form.

 

[Maddad]

centsworthII<br />JonClarke of SDC is the person who needs to see your question. He's a geological research scientists who is developing equipment for the first manned mission to Mars. If anyone could answer you, it would be him.

 

[thechemist]

Hi Centsworth_II,<br /><br />From the Mars Odyssey page : "<i>GRS has allowed scientists to make maps of the elemental composition of the martian surface for the elements hydrogen, silicon, iron, potassium, thorium, and chlorine. These and other chemical elements are the building blocks of minerals, minerals are the building blocks of rocks, and all of these relate to the structure and landforms of the martian surface. "</i><br /><br />So, the GRS maps the total hydrogen distribution (bound water in minerals + free water + ice + all compounds in any state containing hydrogen).<br /><br />However this is not truly limiting the amount of liquid water on Mars, since water bound on inorganic salts is quite mobile and can be freed to the environment (and back) or to other minerals under certain conditions, as studied in the article you mentioned. <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>