Q: My brother and I always liked looking at the stars. In a recent story, it said that a man looked up and saw a supernova explode. Doesn’t that mean it actually exploded 166,000 years ago or about when modern homo sapiens were just starting to evolve in Africa and the light is just now getting here? The story doesn’t say. Also, we usually can’t see possible supernovae with the unaided eye. Well, Hubble and Planck technology was not here 50 years ago, which prompts this question: If one exploded 100 years ago we here on the ground wouldn’t know it. But could the Hubble telescope pick it up earlier and tell us it’s coming?