How Do Scientists Know What Planets And Stars Are Made Of?

Ever wonder how scientists know what the other planets and stars are made of without ever having been to them? Well did you know that each of the elements have their own unique "fingerprint"? Learn how these "fingerprints" are studied and used to determine the composition of astronomical objects.


SOURCES:
http://curious.astro.cornell.edu/ques...
http://upload.wikimedia.org/wikipedia...
https://solarsystem.nasa.gov/multimed...
http://periodictable.com/Samples/002....
http://www2.jpl.nasa.gov/snc/
http://www.space.com/18551-venera-13....
http://en.wikipedia.org/wiki/Venera_13
https://solarsystem.nasa.gov/images/m...
http://static.bbc.co.uk/solarsystem/i...
http://www.scienceinschool.org/reposi...
http://chemistry.bd.psu.edu/jircitano...
http://2.bp.blogspot.com/-6iSugK1DD8Q...
http://en.wikipedia.org/wiki/Pierre_J...
http://en.wikipedia.org/wiki/Norman_L...
http://www.avogadro.co.uk/light/bohr/...