spacetoday.net: Mars water could have been cold and salty

Posted: Thu, May 21, 2009, 6:43 AM ET (1043 GMT)
Mars seen by Hubble August 2003 (STScI)

Liquid water may have existed on Mars early in its history even at sub-freezing temperatures because of the presence of ions in the water. In a paper published in the current issue of Nature, scientists used models of water mixed with sulfur, iron, and other ions at concentrations similar to what is found on the Martian surface today. The studies found that water remained liquid at temperatures as low as -28 degrees Celsius and also precipitated minerals like those seen on Mars today. The required concentrations are not much stronger than found in terrestrial salt water, suggesting that such water could have been hospitable to life. The results may explain why there is geological evidence of liquid water early in the planet's history despite difficulties in developing models of the planet's climate warm enough to support fresh water.