Meteroite impacts may have contributed to the rise of life on Earth, new studies find.
A paper in PNAS last week announced the discovery of a unique class of metal-organic compounds. They were found in meteorites that experienced severe impacts in the past.
This study is an unexpected byproduct of past case studies of meteorite falls led by SETI Institute meteor astronomer and co-author Peter Jenniskens. When these pristinely recovered meteorites were presented to the German team led by Ph. Schmitt-Kopplin of the Helmholtz Center and Technical University in Munich, they measured the methanol-soluble organic compounds at very high mass resolution. Even severely heated and shocked meteorites were found to contain traces of organic compounds. Upon further study, they discovered that many of the surviving compounds had to also contain a metal atom. These metal-organic compounds were identified as mostly di-hydroxy-magnesium carboxylates, a previously unrecognized chemical class. They appear to be a product of impact synthesis and after they are formed in the solid matter of planetesimals, they survive heat and pressure well.
Although these specific compounds have not yet been described on Earth, they may have made conditions for the origin of life on our planet possible. Meteorites rained down on the early Earth together with many small planetesimal impacts. Today, life on Earth has a way of making good use of metal-organic compounds in photo synthesis and the transport of oxygen in our blood. The paper authors speculate that these compounds may have been important by acting as catalysts for creating other complex organic compounds in the prebiotic evolution of life.