SCIENTISTS yesterday said the area around the Mars Pathfinder landing site was hit by a catastrophic flood billions of year ago.
Using pictures from the Pathfinder lander, scientists said floods around the Ares Vallis basin were about the same size as those that created the Mediterranean sea.
Mr Michael Malin, one of the scientists, speculated the flooding was hundreds of kilometres wide and sent water surging at a rate of about one million cubic metres per second.
"A comparable flood on Earth would be the one that filled the Mediterranean Basin," he said.
Evidence of the flood could be seen by the fact that large boulders were stacked up against each other as if they had been pushed by the flood waters, Mr Malin said.
He said he believed that crusts on the rocks were formed by salt and sediment from the flood waters as they receded and left puddles on the rocks. A similar crusting pattern could be seen on rocks in Hawaii thrown out by volcanic activity, he added.
A mission scientist, Mr Matthew Golombek, said the findings so far posed the question, "Could early Mars have been much warmer and wetter?" He added: "The implications are enormous because liquid water is the key ingredient for life."
Signs of the flooding were clearly visible in what the Path-finder scientists refer to as "The Monster Pan" - a vast panoramic view of the dusty red Martian surface and the salmon-coloured sky so large that it is best viewed as a video.
The "Pan" is a composite made up of hundreds of images sent back by the Pathfinder spacecraft following its picture-perfect landing on Mars last Friday.
Other photos unveiled yesterday showed the Sojourner rover backed up against a rock almost as big as itself, affectionately named Barnacle Bill.
Sojourner, a six-wheeled vehicle about the size of a microwave oven, backed up to the rock late on Sunday.
Meanwhile, deadly chemicals, broken glass and other dangers may be lurking behind the hatch of the crash-damaged science module at the Mir space station, a NASA official said yesterday.
"It conjures up a picture that you would only find in a science fiction movie," said Craig Covault, senior space technology editor at the trade journal, Aviation Week. "A US-Russian space crew opens up a dead space station module not knowing what hazards lie behind the door."
Sen John Glenn (75), the first American to orbit the Earth in 1962, is to return to space and become the first pensioner-astronaut next July, in a NASA experiment on ageing and the effects of space on bones and on the human immune system.
NASA spokesmen said yesterday that they had been looking for months at the possibility of sending a healthy septuagenarian on the space shuttle, not as a stunt but as a serious scientific experiment. "The effect of prolonged lack of gravity and the experience of space seem to affect bone structure in ways similar to the human ageing process," a NASA spokesman said.
"I guess returning to space will be a lot less scary than the last time. Back in 1962, bits of my heat shield eroded and my capsule was surrounded by flames all the way down," Sen Glenn recalled.