There may really be Martians after all. Scientists are excited about close-up photographs of the surface of the Red Planet which appear to show traces of water that could support life.
This would be a boost for NASA, which lost two spacecraft on missions to Mars last year, one of which was to find water.
Commenting here yesterday on the pictures from the Mars Global Surveyor spacecraft which has been circling the planet for the past three years, a NASA official, Mr Ed Weiler, said: "If these results prove true, that there is water near the surface, it has profound implications of the possibility of life on Mars."
The pictures of the Gorgonum Chaos region "suggest the presence of sources of liquid water at shallow depths beneath the Martian surface," Michael Malin and Kenneth Edgett write in Science magazine.
There are clear indications of gullies and channels that indicate "groundwater seepage and surface run-off", similar to what happens here when water erodes the Earth's surface.
Scientists have believed for years that water exists on Mars but only as ice in the northern polar cap and as vapour in faint clouds. It is also believed that large quantities of water flowed on Mars, but billions of years ago, and that the water all but disappeared as the planet cooled and its atmosphere thinned.
But with these photographs, Malin and Edgett say they have found signs of groundwater seepage and surface run-off in hundreds of locations, mostly in the high latitudes and in the southern hemisphere.
No water can actually be seen in the pictures, but the scientists say it is unlikely that the gullies and other tracks can be explained by "dry" mass movement such as winds or avalanches.
So when might this water have been flowing? "It might have been a thousand years ago, a million years ago, perhaps even yesterday," Mr Weiler said.
Now NASA is encouraged to go ahead with two more missions to Mars in 2003 and 2005 which will include the use of robots to sample the planet's surface.
If there is liquid water on Mars, this would make travel there easier. Astronauts could convert water into hydrogen and oxygen and use them as rocket fuel and gas for breathing.
Some experts have suggested life originated on Mars. It is widely accepted that Mars would have been war and wet billions of years go before losing its protective atmosphere.