Mars too Salty for Life?

New scientist link - Mars Salt

Heres something interesting -

(EDITED TEXT from New Scientist)
If life ever got going on Mars, it may have been exterminated 4 billion years ago by a buildup of salt. Evidence that the planet is poisonously salty comes from a study of minerals near the Martian surface. They use a fairly abstruse measure of saltiness called "water activity", which decreases as you add salt to water. Pure water has an activity of 1; seawater 0.98. Few terrestrial organisms can survive at a water activity below 0.85.

I have never heard this before but it seems plausibe what do people here think??

[edit on 29-5-2008 by oinkment]

My first thought was that not long ago scientists were jumping up and down getting all exited because they found salt. Now there is tto much? Also, in order for there to have been life there must have been liquid water. We have no idea if it did let alone how much there might have been.
Just my thoughts....

I kinda know what you mean the impression i got when they first found water and salt deposits - was that mars was covered in shallow warm seas in its early history where lots of interesting life forms could of had a foothold.

But it seems that if they were any shallow seas they were a thick "brine" and possibly sterile as the salt content was very high.

However I always thought the earths seas were salty due to intense weathering - "weather" on mars seems kinda mild so how did its seas get so salty so early??

Originally posted by oinkment
- "weather" on mars seems kinda mild so how did its seas get so salty so early??

Mild? I would say yes of the Mars we see today but oceans affect weather and who knows what it was like back when mars had large amounts of surface water but being too salty kind makes since like Salt Lake, or the Dead Sea where slowly the ocean water is evaporated away and you end up with things like the Salt Flat etc.

While Mars has potential for having such a high salinity, that doesn't completely rule out life. There are organisms that can strive, and some that even depend, on high concentrations of salt.

For example, the algae Dunaliella salina lives in fresh waters but can also be found in the Dead Sea. On top of that, proteins called halophilic proteins actually depend on high concentrations of salt to form. Granted, a protein isn't an actual living organism, but it's progress in the right direction.

Source - Astrobio.net