Nasa scientists are getting very excited by the latest images from Mars indicating the presence of liquid water. It boosts the case for life on the planet. The orbiter Global Surveyer detected apparent changes in crater walls possibly caused by the recent flow of water. Nasa’s Dr Kenneth Edgette: “We have been able to image gullies repeatedly, the same ones over and over again, and in doing that, we found…. changes, that indicated material had actually flowed through a gully and made a deposit that would indicate by its shape that a liquid was involved.” Scientists previously had established that two forms of water — ice at the poles and water vapour — exist on Mars, but liquid water is crucial to nurture life. It has been suggested that if water is found it could be used as a resource for future missions to explore the planet.