Detecting chiral asymmetry in the interstellar medium using propylene oxide

(Abridged) Life is distinctly homochiral. The origins of this homochirality are under active debate. Recently, propylene-oxide has been detected in the gas-phase interstellar medium (ISM) (McGuire et al. 2016). enantiomeric composition ISM may be probed through circular polarization measurements, but accurate estimates dichroism properties microwave transitions not available. We develop a model dichroic activity torsion-rotation closed-shell chiral molecules, such as propylene-oxide. With model, we estimate viability, and optimize observation strategies, excess detection present for propylene-oxide, where predict that fractions emission lines enantiopure relevant to astronomical on order 10^(-6). Due low predicted fractions, conclude characterization gas phase impossible with current techniques. suggest only radical species viably employed detection. laboratory experiments successful detecting mixture spectroscopy. theory paper provides solid theoretical underpinning measurements transitions.