Ok.  Scientists say they have it figured out.  Kind of anyway.  Maybe "figured out" is pushing it, but narrowed down, at least. 

They claim now that is definitely a "natural" substance.  It's not man-made.  So their verdict as to WHAT it exactly is...Eggs. 

Eggs?  What kind of eggs?  They don't know.  At least, not yet. 

Read the article below.