Strongest evidence water still flows occasionally on Mars

A spacecraft orbiting Mars has discovered compelling evidence that water has cascaded down the slopes of at least two Martian craters within the past seven years, forming mile-long gullies where the water has frozen instantly into brilliant ice, NASA scientists announced Wednesday.

The canyons, flood plains and deeply carved terrain all across the planet has long convinced researchers that millions of years ago Mars must have been warm and wet and easily capable of supporting life and within the past five years most scientists have talked about water flowing on the planet millions of years ago.

Now, however, recent images from the Mars Global Surveyor clearly show bright streaks on two crater slopes that the spacecraft's cameras only caught within the past two years.

"These observations give the strongest evidence to date that water still flows occasionally on the surface of Mars," said Michael Meyer, chief scientist for NASA's Mars exploration program in a Washington briefing carried live over the Internet.

But neither Meyer nor the scientists responsible for the camera that took the extraordinarily high-resolution images could explain where the water came from: whether it burst from deep underground, came from the melting of unsuspected snow that had formed in the deep, cold shadows of the crater walls or came from other sources.