Solar spectrum... This is the best image I've ever seen of the solar spectrum in visible light. Each of the black bands represents absorption lines for molecules that lie between the sun and the spectrometer. There are so many of them! If you expand this spectrum, you'll see that some of the absorption lines look “fuzzy” – these are the absorption lines of molecules at a wide range of temperatures. I first ran into these absorption lines when reading about the discovery of helium, and I've read much more since then. Still there was a big surprise for me in here: some of the absorption lines are still unidentified – they're being caused by a molecule (possibly an element) that we don't yet know about. Via APOD, of course. Full resolution version here.