Here's the paradox - Earth seems to be too close to the Sun to have formed with liquid water, so where did we get enough water to cover 70% of the planet's surface?
UA planetary science professor Mike Drake will be featured on this week's episode of the National Geographic Channel series "Naked Science" on the topic of "Birth of the Oceans," which explores where Earth got its water.
Mike discovered that olivine and other common minerals adsorb an astonishing amount of water – enough to create 10 times the volume of water currently found in Earth's oceans. So, his conclusion is that before the planets formed 4.5 billion years ago, an enormous expanse of fine dust grains swirled in a vast sea of hydrogen, helium and oxygen around the sun. Hydrogen and oxygen reacted to make water, creating a disk of basically dust surrounded by water.
Mike concludes that, "At least some, if not most, of Earth's water had to come from adsorption of water onto grains before the planet ever formed."