Ancient valleys may hold clues to past life on Mars
Ancient valleys on Mars are similar to ones that exist around Devon Island in the Canadian Arctic Archipelago. Both on Earth and on Mars, valleys left by icy channels are distinctive because they can flow uphill, the researchers observed. (Grau Galofre/ASU/)The southern hemisphere of Mars contains hundreds of networks of valleys that have long puzzled geologists. They believe erosion from liquid water created these ancient depressions, which indicate that early Mars was a relatively warm place. But past computer models have suggested conditions on the red planet were cold and icy during that time period period.Recently, planetary scientists took a closer look at those Martian valleys and compared them with similar formations on Earth. The researchers found that water flowing under ice sheets helped construct a significant proportion of the valleys, confirming that Mars did indeed have a chilly, frigid chapter in its early history. The team reported these findings...