What locations would you go see if you had a chance to visit the surface of Mars?

Clay deposits found in one of the oldest riverbed-like channels on Mars shows some unusual signatures that may shed light on the history of water -- and possibly life -- on the red planet. Observations made by an instrument onboard NASA's Mars Reconnaissance Orbiter (MRO), currently circling the planet, already have shown substantial clay deposits that formed about 4 billion years ago in two regions of Mars, Mawrth Vallis and Nili Fossae, that indicate that water was more widespread in those areas than was initially thought.

Two studies based on data from NASA's Mars Reconnaissance Orbiter have revealed that the Red Planet once hosted vast lakes, flowing rivers and a variety of other wet environments that had the potential to support life.

During its first week of observations from low orbit, NASA's newest Mars spacecraft is already revealing new clues about both recent and ancient environments on the red planet.

Substantial quantities of liquid water must have been stably present in the early history of Mars. The findings of OMEGA, on board ESA's Mars Express, have implications on the climatic history of the planet and the question of its 'habitability' at some point in its history.