According to the Drake equation there may be millions of planets within our galaxy...
So, the question is, if there is an advanced civilization out there, would it or could it invade and destroy us?
If that civilization already exists and is able to reach Earth...
This is a scenario that could, maybe, happen but, for right now, appears to be more fiction than reality.
The last supernova seen with the human eye was documented by Johannes Kepler in 1604...
However, were a supernova to go off within about 30 light years of us...
Supernovae happen about once every 100 years in the Milky Way...
Dr. Mark Reid, Harvard-Smithsonian Center for Astrophysics
