A New Paradigm to Explain Amino Acid Chirality and Isotopic Anomalies in Meteorites

The Supernova Neutrino Amino Acid Processing (SNAAP) model selects left-handed amino acids (AAs) via electron anti-neutrinos interacting with $^{14}$N (spin 1) nuclei oriented by a magnetic field. Within the AAs, the shielding tensor alters the local magnetic field in a way that is sensitive to molecular chirality. A binary system of a Wolf-Rayet star and a neutron star, when the WR star explodes, or a two-neutron star merger, might supply the required magnetic field and anti-neutrinos. An accretion disk around a neutron star could enable meteoroid and AA formation. Quantum molecular calculations that included perturbation effects on the shielding tensor for N from the reorientation of the molecular electric dipole showed the AAs moving in an external magnetic field to be chirally distinct. An enantiomeric excess of a fraction of a percent was found for isovaline and alanine. Isotopic anomalies have also been observed in meteoritic AAs; they agree qualitatively with model predictions. These results suggest the Galaxy might have been seeded with AAs by one such system. Measurements of $^{60}$Fe (T$_{1/2}$=1.6 My) in ancient meteorites suggest that required events have occurred close to Earth.