How are astronomers able to identify chemicals in distant space?

*Answer has something to do with line spectra

Question

How are astronomers able to identify chemicals in distant space?

*Answer has something to do with line spectra

compassionate · Answer

You mean Red Shift.

anonymous · Answer

I don't know what that is, so probably not.

compassionate · Answer

Spectral Analysis. They break the light apart into a spectrum and find either emission lines or absorption lines and that tells them what elements are present. For a more detailed explanation, check out the link below. Source: http://imagine.gsfc.nasa.gov/docs/scienc...

anonymous · Answer

I think we're only talking about emission lines but I'm not sure.  Also that link doesn't work

anonymous · Answer

does it make sense to say they use a diffraction grating? if it does what purpose does that serve

compassionate · Answer

IT's exactly as I said it was.