Rover discovers evidence of drinkable water in Mars’s past

BBC : Opportunity, the rover that landed on Mars in 2004 for a 90-day mission, is still making discoveries 9 years later. Its newest discovery may be one of its most importantâmdash;a rock with large clay deposits. The presence of clays indicates that the rock had prolonged exposure to water at some point in the past. Evidence of acidic water has been previously found, but clays usually form in neutral, and therefore drinkable, water. Neutral water is also more favorable for the development of prebiotic chemicals. The new finding supports similar clay findings by the rover Curiosity on the other side of the planet. Opportunity cannot directly sample the clays to determine the specific minerals. Instead, it uses x-ray spectroscopy to determine what elements are present. Despite the decline in the rover’s abilities, the team of researchers operating Opportunity are continuing to explore and search for more evidence into the history of Mars.