Astronomers found evidence, in the form of newly carved gullies, that liquid water has flowed on Mars within the last five years; skeptics suggested that the channels were made by avalanches of carbon dioxide or rivers of dust.
Astronomers found evidence, in the form of newly carved gullies, that liquid water has flowed on Mars within the last five years; skeptics suggested that the channels were made by avalanches of carbon dioxide or rivers of dust.