Nano Geoscience and the Hunt for Stardust
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Beschreibung
More than 4.5Ga ago our solar system was
formed from a mixture of gas and dust. In the shells of dying stars and during
supernova explosions dust grains are formed and processed, contributing to the
molecular cloud from which our solar system evolved.
The authors describe how they, by applying modern analytical techniques with
nanoscale to atomic resolution, are now able to identify and characterize these
building blocks and to decipher in great detail the processing of this material
from which habitable planets, such as Earth, are formed. With a spatial
resolution of less than 50nm it is possible to measure the main, minor and
trace elemental composition, the isotopic ratios, valence states and structural
details, like long and short range order, defects and indicator micro
structures of phase transformations. Their study of
pristine asteroidal, cometary and contemporary interstellar matter yield new
exciting insights into the formation of the solar system. We discovered an
unexpected high amount of phases in cometary dust from Comet Wild 2 sampled
during NASA´s Stardust mission that is formed at high temperature (> 1000°C) in the inner part of the protoplanetary nebula close to the proto-sun, and we identified presolar Mg-Si-perovskite in the matrix of the pristine meteorite Acfer094 most likely formed during a supernova shock wave or low temperature condensation still before our solar system was formed.
Autor*in
Frank E Brenker
Themen in »Nano Geoscience and the Hunt for Stardust«
cometary dust isotopic ratio nano geoscience solar system stardust valence state