Using Light's Handedness To Find Alien Life 210
Rational Egoist writes "Scientists working at the National Institute of Standards and Technology have come up with a novel, easy 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. From the article: '"If the [planet's] surface had just a collection of random chiral molecules, half would go left, half right," Germer says. "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.' The article abstract is available online."
Re:How about earth? (Score:3, Insightful)
What 'handedness' is earth?
I have no idea. But I'm not sure it matters. Even if Earth was perfectly neutral the method still works. If the presumption is true then any planet significantly away from average would indicate life. Even if it wouldn't find planets with life that were average.
Wow (Score:5, Insightful)
Test it on Europa (Score:3, Insightful)
Surely this would be a good test to check out Europa?
Even though the ice crust might obfuscate things, if the light was from reflected from the area of a crevice/crack then there would be elements (or the lack thereof) in the frozen water that give some indication.
Re:I'm sceptical.... (Score:4, Insightful)
Not all molecules are chiral. Simple molecules which form the raw materials for life forms are not themselves chiral because they are symmetrical (O2, H20, NH3, CO2, etc; chirality is only possible for asymmetric forms molecules). The simplest solution the problem you describe is to introduce simpler lifeforms from earth--bacteria or archaea to start producing organic molecules of the correct chirality from the raw material precursors.