Reflections of Chirality as a Possible Biomarker

April 30, 2009 / Posted by: Daniella Scalice

Scientists have come up with a novel way to detect life on other planets. Rather than try to measure the composition of atmospheres, they want to look at the chirality of light coming from the planet. “If the [planet’s] surface had just a collection of random chiral molecules, half would go left, half right,” says author T.A. Germer of the National Institute of Standards and Technology. “But life’s self-assembly means they all would go one way. It’s hard to imagine a planet’s surface exhibiting handedness without the presence of self assembly, which is an essential component of life.” And they have already built a working model: because chiral molecules reflect light in a way that indicates their handedness, the research team built a device to shine light on plant leaves and bacteria, and then detect the polarized reflections from the organisms’ chlorophyll from a short distance away. The device detected chirality from both sources. Their paper is published in a recent issue of the Journal of Quantitative Spectroscopy and Radiative Transfer.