Just in case you need something fresh to worry about: recent observations of T Pyxidis, a rare "recurrent nova" consisting of a white dwarf and a sun-like companion orbiting each other -- show that it is much closer than previously thought (just 3,260 light years) and that it could eventually (in about ten million years) go supernova.
A supernova that "close" (in cosmic terms) could alter our atmosphere and destroy the ozone layer, with cataclysmic results for life here on our pale blue dot.