Liquid water may flow on Mars

New York Times : As scientists report today in Science, Mars may have liquid water flowing on its surface. They base their theory on the observation of fingerlike streaks up to five yards wide on some of the planet’s steep slopes. The streaks, which appear to grow and shift in summer and fade in winter, showed up on high-resolution photographs taken by NASA’s Mars Reconnaissance Orbiter, which arrived at Mars in 2006. Principal investigator Alfred McEwen of the University of Arizona and colleagues surmise that any water on Mars’s surface would have to be extremely salty in order to stay liquid at such cold temperatures. The possible presence of liquid water is certain to revive speculation that Mars is teeming with microbial organisms, writes Kenneth Chang for the New York Times.