Small bodies and big impacts: comets, asteroids, and the origin of water and organics on Earth

Autores
Dr.
Humberto Campins
Fecha y hora
7 Oct 2008 - 00:00 Europe/London
Dirección

Aula

Idioma de la charla
Inglés
Idioma de la presentación
Inglés
Número en la serie
0
Descripción

The role of asteroids and comet impacts on the origin of Earth’s water and organic molecules is reviewed. Earth is believed to have formed dry, and magma oceans probably destroyed any primordial organics on Earth. The oldest clear evidence for water on Earth is about 3.85 Ga, right after the “Late Heavy Bombardment” (LHB). Asteroid and comet impacts during the LHB probably contributed significantly to Earth’s water and organic inventory. Evidence for this contribution is found in the D/H isotopic ratios of meteorites and comets. The abundance and variety of organic solids in asteroids and comets also point at a significant contribution to the organic inventory of the early Earth. However, the pieces of this puzzle do not all fit into a neat picture and several questions remain unanswered.