Martian salt

Evidence of an ancient lake on Mars could be the biggest hint of habitable surface water, according to researchers at the University of Colorado Boulder, USA. The team examined data from a large chloride salt deposit (approximately the size of the city of Boulder itself) in the planet’s Meridiani region near the site where NASA's Mars Opportunity rover landed. On Earth at places like Utah’s Bonneville Salt Flats, such large-scale salt deposits are known to be the desiccated remnants of large bodies of water.