QUESTION:
Where does the methane in space come from?

ANSWER from Jesse Bregman on May 16:
Methane is a combination of one carbon and 4 hydrogen atoms.  The most
common atom in our galaxy is hydrogen, followed by helium, oxygen, 
nitrogen, and carbon.  Methane will naturally form in places where there 
is carbon and hydrogen.  This might be around stars or in interstellar
space or even in dark clouds.  Some fraction of the gas will form
methane, while other molecules will also form.  Some of the most abundant
molecules are carbon monoxide and polycyclic aromatic hydrocarbons
(large molecules which are essentially a collection of benzene rings--
this is also the black stuff in the middle of roadways which comes from
auto exhaust).