The Universe: Mars, new evidence

In recent years there are new clues that suggest the possible existence of life on Mars. Today there is evidence to confirm the existence of water flowing over the surface and lakes, and further that the Polar ice caps are composed primarily of water and carbon dioxide as previously thought. On Mars there is snow and lightning are caused by dust storms. Most intriguing of all are seasonal emissions of methane, which could indicate the existence of bacteria below the surface.