If we lived on a planet circling a star about to go supernova, would we know it was going to happen?
DEE SHARPLES, HONEOYE FALLS, NEW YORK
There is no clear answer. The seeds of catastrophe that will destroy a star in a supernova are buried deep in the star's heart, but all we can see easily is the surface, buffered by the stellar mass in between. There were images of SK –69°202, the star that blew up as SN 1987A, but no clue in those images of an impending eruption.