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
Mars Express half of comparable U.S. missions. On 19 October 2014, the ESA reported the "Mars Express" was healthy after the Comet Siding Spring flyby of Mars on 19 October 2014 — as are, as well, all NASA Mars orbiters and ISRO's orbiter, the Mars Orbiter Mission. Arriving at Mars in 2003, ago (and counting), it is the second longest surviving, continually active spacecraft in orbit around a planet other than Earth, behind only NASA's still active 2001 Mars Odyssey. The "Mars Express" mission is dedicated to the orbital (and originally in-situ) study of the interior, subsurface, surface and atmosphere, and environment