Gamma ray bursts and supernovas??

I have been reading on the internet about gamma ray bursts, and if one were to occur near earth it is over for us.
I still dont understand where they come from? From supernovas?
There isn't much we can do if one were to occur which worries me.

What is the likely hood of gamma ray bursts or supernovas causing a threat to earth..?

reply to post by Amgi2005


I am not 100 percent sure but I think some if not all may occur near or are caused from black holes. Good question though.

Wiki?

Second paragraph seems to suffice.

I know that wiki is not always a good friend of ATS, but honestly this article is a good one: en.wikipedia.org....

As you'll see, there is an amazing low chance that any GRB would cause any kind of trouble on earth... given the enormous distances at which they appear for the most part.