Solar System Exploration Research Virtual Institute (SSERVI)
NASA | Ames Research Center (ARC) | 2014 July 31
New research shows that more than four billion years ago the surface of Earth was heavily reprocessed – or melted, mixed, and buried – as a result of giant asteroid impacts. A new terrestrial bombardment model, calibrated using existing lunar and terrestrial data, sheds light on the role asteroid collisions played in the evolution of the uppermost layers of the early Earth during the geologic eon called the “Hadean” (approximately 4 to 4.5 billion years ago).An artistic conception of the early Earth, showing a surface pummeled by large impacts,Click to play embedded YouTube video.
resulting in extrusion of deep seated magma onto the surface. At the same time, distal
portions of the surface could have retained liquid water. Credit: Simone Marchi/SwRI.
An international team of researchers from academic and government institutions, including NASA’s Solar System Exploration Research Virtual Institute (SSERVI) at NASA’s Ames Research Center in Moffett Field, California, published their findings in a paper, “Widespread Mixing and Burial of Earth’s Hadean Crust by Asteroid Impacts” in the July 31, 2014 issue of Nature.
“A large asteroid impact could have buried a substantial amount of Earth’s crust with impact-generated melt,” said Yvonne Pendleton, SSERVI Director at Ames. “This new model helps explain how repeated asteroid impacts may have buried Earth’s earliest and oldest rocks.” ...
More animations and images at the Lunar and Planetary Institute: http://www.lpi.usra.edu/exploration/HadeanEarth/
Early Earth: A Battered, Hellish World with Water Oases for Life
Space.com | Charles Q. Choi | 2014 July 31
Widespread mixing and burial of Earth’s Hadean crust by asteroid impacts - Simone Marchi et al
- Nature 511(7511) 578 (31 July 2014) DOI: 10.1038/nature13539