A major mystery of life on Earth is that organisms are exclusively made up of left-handed amino acids. A number of different theories exist for why left chirality was chosen over right (1, 2, 3, 4). A new astronomic observation of the Orion Nebula has shown that much of the star forming region is bathed in circularly polarized light. Though ultraviolet light has the energy necessary to influence chirality and the observation is of visible light, the researchers from the National Astronomical Observatory of Japan believe that large scale polarized ultraviolet light exists in the Orion Nebula though we can’t see it due to intra-stellar interference. If ultraviolet polarized light bathed our solar system during formation, it could have pushed left-handedness to dominate the balance of chirality.
We present a wide-field (~6’x6′) and deep near-infrared (Ks band: 2.14 micro m) circular polarization image in the Orion nebula, where massive stars and many low-mass stars are forming. Our results reveal that a high circular polarization region is spatially extended (~0.4 pc) around the massive star-forming region, the BN/KL nebula. However, other regions, including the linearly polarized Orion bar, show no significant circular polarization. Most of the low-mass young stars do not show detectable extended structure in either linear or circular polarization, in contrast to the BN/KL nebula. If our solar system formed in a massive star-forming region and was irradiated by net circularly polarized radiation, then enantiomeric excesses could have been induced, through asymmetric photochemistry, in the parent bodies of the meteorites and subsequently delivered to Earth. These could then have played a role in the development of biological homochirality on Earth.
Article in arXiv: Extended High Circular Polarization in the Orion Massive Star Forming Region: Implications for the Origin of Homochirality in the Solar System…
Image credit: Don J. McCrady
(hat tip: Physics arXiv Blog)