Water on Mars any point in the year but would be ideal for solid carbon dioxide. The carbon dioxide melting in the warmer summer would yield liquid carbon dioxide which would then form the gullies. Even if gullies are carved by flowing water at the surface, the exact source of the water and the mechanisms behind its motion are not understood. The dry gullies are deep grooves etched into the slopes that are there year-round. There are many other features on Mars, and some of them change seasonally. In August 2011, NASA announced the discovery by undergraduate student Lujendra Ojha of current seasonal
Water on Mars lakes and streams existed in Gale crater 3.3 – 3.8 billion years ago delivering sediments to build up the lower layers of Mount Sharp. On November 4, 2018, geologists presented evidence, based on studies in Gale Crater by the "Curiosity" rover, that there was plenty of water on early Mars. The "Mars Express Orbiter", launched by the European Space Agency, has been mapping the surface of Mars and using radar equipment to look for evidence of sub-surface water. Between 2012 and 2015, the "Orbiter" scanned the area beneath the ice caps on the Planum Australe. Scientists determined by 2018 that