The GRO is the first look we've had at the gamma-ray sky. So, everywhere we've looked
with the observatory, we've discovered new things. And some of those things have
included the gamma-ray bursts, discovery of gamma-ray quasars, and another
interesting thing about the gamma-ray sky is that it's always changing and variable
and so sometimes we'll go back and look at a given place in the sky and find that
it's changed since the last time we looked.