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 aircraft by NASA in the 1990s for a Mars airplane to fly on Mars by the anniversary of the Wright Brothers's first flight, in the "Faster, Better, Cheaper" era; and the ARES Mars airplane proposal was selected as a Mars Scout Program candidate, but not selected for flight. In 2015, a Mars aircraft was considered as an option in the re-boot of the Japanese MELOS mission. One early design proposed a wing-span of 1.2m, a mass of 2.1 kg, and with the following mission profile: During the landing phase of the surface element of MELOS, the aircraft would be released at