Free Republic

Five billion years ago, the universe was Earth-less. It remained that way till a vast number of asteroids smashed together and compacted into a giant rocky orb. But that raises a question: The Earth's surface is 70% water, so where'd the liquid come from? A long-standing theory is that a water-rich class of asteroids, called carbonaceous or C-type asteroids, could've pelted the Earth during its creation and brought along water. There's a caveat though, and the C-type asteroids may be only half the story....

Posted on November 9, 2018November 9, 2018 by Evan Gough Not all the Earth’s Water Came From Comets We have comets and asteroids to thank for Earth’s water, according to the most widely-held theory among scientists. But it’s not that cut-and-dried. It’s still a bit of a mystery, and a new study suggests that not all of Earth’s water was delivered to our planet that way.Hydrogen is the most abundant element in the universe, and it’s at the center of the question surrounding Earth’s water. This new study was co-led by Peter Buseck, Regents’ Professor in the School of...

Scientists have long believed that comets and, or a type of very primitive meteorite called carbonaceous chondrites were the sources of early Earth's volatile elements -- which include hydrogen, nitrogen, and carbon -- and possibly organic material, too. Understanding where these volatiles came from is crucial for determining the origins of both water and life on the planet. New research led by Carnegie's Conel Alexander focuses on frozen water that was distributed throughout much of the early Solar System, but probably not in the materials that aggregated to initially form Earth... It has been suggested that both comets and carbonaceous...