I have heard an interesting claim that looks fishy to me. The claim is that during the last 10,000 years there hasn't been a single Supernova eruption closer than about 5,000 light years. And that somehow this is an anomaly. That the background rate of nearby supernovas is much higher. And so we are living in some sort of goldilocks time with respect to this threat. I suspect this is not correct (thats its anomalous ) but am looking for guidance. Any help much welcome.