Washington, March 21 (Xinhua) The US National Aeronautics and Space Administration (NASA) has said that its Mars Odyssey Orbiter found evidence of salt deposits on Mars, giving hope the environment could have supported primitive life.

These deposits point to places where water was once abundant and where evidence might exist of possible Martian life from the red planet's past, said NASA on its website Thursday.

A team led by Mikki Osterloo of the University of Hawaii found approximately 200 sites, ranging from about one sq km to 25 times that size on southern Mars that show spectral characteristics consistent with chloride minerals.

Chloride is part of many types of salt, such as sodium chloride or table salt.

'They could come from groundwater reaching the surface in low spots,' Osterloo said. 'The water would evaporate and leave mineral deposits, which build up over the years. The sites are disconnected, so they are unlikely to be the remnants of a global ocean.'

Osterloo's team reported the findings in Friday's issue of the journal Science. They think the salt deposits formed approximately 3.5 billion to 3.9 billion years ago, while several lines of evidence suggest Mars then had intermittent periods with substantially wetter and warmer conditions than today's dry, frigid climate.

Scientists looking for evidence of past life on Mars have focussed mainly on a handful of places that show evidence of clay or sulphate minerals.

Clays indicate weathering by water, and sulphates may have formed by water evaporation. The new research, however, suggests an alternative mineral target to explore for biological remains.