Tuesday, March 14, 2006

Pocket-sized spectrometer from the University of Arizona

NASA's 2009 Mission to Mars will carry the Mars Science Laboratory, which includes a cell-phone-sized device capable of identifying minerals in the Martian soil. The device, designed by Robert Downs at the University of Arizona, shoots a laser at materials to be identified, causing its atoms to vibrate at different frequencies and generate a detectible signal. The process, known as Raman spectroscopy, is a quantum mechanical process that earned its discoverer, Sir Chandrasekhara Venkata Raman, the Nobel prize in physics in 1930.

Excerpts from an interview with Downs:
I know that Miami Police Department has about 220,000 spectra of all the illicit drugs that are out there in the world. You just take these things; you can shoot them and ten second later you know what they’re holding: is it baby powder, is it cocaine? Really easy to tell. This little white powder that came in envelopes that the post office was getting. Bonner Denton has a demonstration he uses upstairs. He takes a bottle of Tylenol, a white plastic container and the pills are inside. You can shoot the Raman and a laser goes through that white plastic, it identifies the three parts of Tylenol and it tells you what the plastic is made out of. It works on leaves. I can identify the species of trees by shooting their leaves. I don’t think the biologists are aware of this yet.


There is about just over 4000 mineral species that are known and we’ve shot about 700 of them so far; so, one fifth of the way. I think it will be about a six-year project to complete everything we know found on Earth. And we’re also looking at the meteorites as well with the NASA people.
(Via jwz's blog.)

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