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Life Light

May 12, 2009

The way light scatters off distant planets may reveal whether life exists on them.


A new way to search for alien life. I’m Bob Hirshon and this is Science Update.

Finding life on distant planets may someday become easier, by analyzing the light that reflects off of them. That’s an idea being developed by Bill Sparks of the Space Telescope Science Institute in Baltimore, and colleagues like physicist Thomas Germer of the National Institute of Standards and Technology. Germer explains that the molecules in living things tend to scatter light in a particular direction – a phenomenon called polarization.

THOMAS GERMER (National Institute of Standards and Technology):
If we see a net circular polarization coming from the planet, it’s hard to imagine that coming from anything other than life.

Their team has developed an instrument that can detect that kind of polarization. So far, it’s all in the lab, but the next step is to try it from a distance outdoors, and ultimately, from across space. I’m Bob Hirshon for AAAS, the Science Society.