but while the moon's face has changed little, the archaean earth looked nothing like the world today. none of our familiar continents. no green blush of life on land. but dive into those ancient australian seas and you would have found the first stirrings of life. it probably looked like this: slime. some of the earliest tantalizing signs of what could be fossilized bacteria appear in western australian rocks around 3.5 billion years ago, not long after the meteor bombardment ended. while the details of the origin of life remain shrouded by the mists of time, scientists are starting to get a fix on when and probably where it happened. and one thing is for sure: the early earth had plenty of the raw ingredients. a reliable supply of water, heat and biologically useful chemicals could all be found close to volcanic vents, like in these hydrothermal pools in new zealand. this blistering water contains no free oxygen. instead, it's rich in poisons like hydrogen sulfide and arsenic. and rich in life, too. the orange scum lining the rocks is a jungle of primitive bacteria and archaic microo