Earth’s water
EARTH’S WATER MIGHT HAVE COME FROM ANCIENT SPACE ROCKS
Water might have existed in the building blocks of our world
Reported by Rahul Rao
Earth and the rest of our Solar System’s inner rocky planets are the products of a myriad of tiny planetesimals – glorified E pebbles of primordial cosmic dust – assembling themselves together more than 4 billion years ago. Now, a new analysis suggests that those planetesimals already contained water. Researchers tested samples from meteorites that they say are just as ancient as those planetesimals. In doing so, they found the fingerprints of chemical reactions known to occur in the presence of water. There is no water to be found in these samples today, but scientists can still trace water that they once held. Over time, if water is in the presence of other elements, the water molecules’ oxygen atoms will separate and join up with those very elements. Water and iron, for instance, will beget iron oxide. That’s the substance that colours Mars’ surface rust-red.