what is a supernova and how does it affect us?
A supernova is an explosion at the very end of the life of certain types of stars. You can find more information about supernovae at http://starchild.gsfc.nasa.gov/docs/StarChild/universe_level2/stars.html in the section about massive stars. There is much more information also included in our Imagine the Universe! web site you can find by going to: http://imagine.gsfc.nasa.gov/ and click on the search button and asking it to search for “supernova”. These pages explain what a supernova is, how they happen, and the different kinds of supernovae. These will answer your question about what a supernova is. Your other question was about how supernovae affect us. They can affect us in some important ways. First and foremost, we and much of the Earth are made of the material supernovae created. According to current theories about the formation of the Universe, all of the original material in the Universe was hydrogen and helium, with very slight traces of some other materials. All the stuff we
