Nasa scientists last night confirmed that there is water on Mars. The space agency's Phoenix lander has identified ice in a soil sample analysed by its on-board laboratory.

Previous orbiting missions had beamed data such as the view of the planet's surface, above. Others indicated there was ice on the red planet - but Phoenix's discovery is the first direct evidence. "I can now say I'm the first mission to Mars to touch and then taste the water," came the message from Phoenix's Twitter feed yesterday.

Nasa has extended the mission until September 30, adding five weeks to the scheduled 90 days of operations on the surface.

"Phoenix is healthy and the projections for solar power look good, so we want to take full advantage of having this resource in one of the most interesting locations on Mars," said Michael Meyer, chief scientist for the Mars exploration programme at Nasa HQ in Washington.

The soil sample was scraped out of the roughly five-centimetre deep "Snow White" trench on Wednesday. Two previous attempts to deliver fresh material to the lander's on-board oven failed when the soil became stuck in the scoop. This time the scientists exposed most of the material in the sample to the air for two days, so some water vapourised, thus making the soil easier to handle. The find fulfils one of the Phoenix lander's two main objectives - to "study the history of water in the Martian arctic". The other is to study the potential for life in the ice-soil boundary.

In 2006, Nasa scientists, using images from the orbiter, Mars Global Surveyor, found evidence of water flowing fleetingly on the surface. They compared images of the side of a crater taken in 2001 and 2005. The second showed gullies apparently caused by water bursting out of the crater wall.