| | Deep Impact: Science: Spectroscopy (Site not responding. Last check: 2007-10-23) |
 | | When you separate the light that is passing through a sample, or reflecting off a sample, you end up with an emission spectrum or absorption spectrum, as opposed to the continuous spectrum you would get if you break up a source of all wavelengths of light. |
 | | Such a spectrum would be created when material is given extra energy somehow (it's heated, electrified, radiated with light, etc.) and that extra energy is later emitted as light energy. |
 | | The emission or absorption spectrum of a substance is as unique to that substance as a fingerprint is to a human being. |
| deepimpact.jpl.nasa.gov /science/spectroscopy.html (953 words) |