I think it's bugged.
There's signals everywhere, so many that it's almost impossible to distinguish them. But most times when I'm able to single out one signal and get it right in front of me, it disappears as i approach it. Then if i back up, the signal is gone like it was never there. All the signals appear to "should have been" at rocks that looks like they would have a crystal on it. But there are nothing there. I found quite a few Needles, but not "you should totally do a 30 jump tour" many.
I wonder if its bugged in the same way as mining, i.e. suddenly an asteroid will blow up because some one at the same location in another instance is actually in your instance but you can't see them.
I tried at Geo site 15 and 4.
My guess there is a bunch of people there right now. I also got kicked off the server, indicating this.