What would a gamma-ray burst 7,500 light years away to do Earth and humans?
What effect if any it would have depends on two factors, the distance from earth and if one of the jets spat out by the newborn black hole irradiates the Earth. An ordinary core-collapse supernova from that distance would be a spectacular light show if no dense concentrations of interstellar dust obscure it, but would do no harm to us on the ground. Satellites would record a surge of x-rays and gamma rays, but whatever dose a man in space would get, would in an of itself not be harmful. A hypernova however focuses the energy of as much as trillion Suns into two laser beam like jets that are tightly collimated and focused. If the jest miss us, we just see a very bright supernova because we have a clear view of Eta Carinae and astronomers would have the chance of a lifetime to watch a supernova unfold. If on the other hand, one of the jets does blast or rake the Earth, it could result in dire effects on the biosphere because of a disrupted ozone layer, which immediately leads to disastro
