Probe confirms water on Mars

Washington: After years of proposing, theorising and deducing that there is water on Mars - at least in the form of ice - Nasa scientists said they have finally confirmed it, after the Phoenix lander detected traces of water vapour wafting off a scoop of Martian dirt, researchers said.

"It's something we've been waiting quite a while for," said William Boynton of the University of Arizona, describing how a tiny "oven" on the lander heated the dirt until ice mixed with it evaporated. "We've now finally touched it and tasted it."

Earlier Mars expeditions had indicated that at least in the past, water existed on Mars - a key issue for scientists, since on Earth, liquid water is a key prerequisite for life. In the 1970s, photos seemed to show channels on the Red Planet's surface, a possible indication that water had flowed there before the atmosphere cooled.

But that was a deduction: on Thursday, scientists said they had proof. The probe, which includes implements for scooping and gouging the Martian surface, had cooked a dirt sample in a special oven, and the scientists noted that a bit of the sample evaporated around the usual freezing point of water.

"The fact that it melted at zero degrees Celsius leaves very little doubt that it is standard water ice," Boynton said. He said sensors also tested the chemical makeup of the vapour and found the familiar combination of two hydrogen atoms and one oxygen atom.

Nasa has also announced that the Phoenix mission, originally planned to finish in late August, would be extended through the end of September. That extension will cost about $2 million, a Nasa official said.