OT. Quasar Mystery Solved.

You mean it's been "solved" for this week. Astrophysics seems to abound with wonderful answers to all sorts of things, until someone comes up with a different explanation.

There are three unrelated stories linked to in that quasar article, all of which have a new explanation about something:

We are quite a way from the galactic centre so we might get to watch the fireworks from close up. Our galaxy's BH and the one in M31 is by chance quite modest so it might still be a bit of a non-event. Galaxies consist of stars and a heck of a lot of empty space between them. Nearest to are sun are 4 light years away. It is pretty much like smoke colliding.

By sheer coincidence the BH at the centre of the giant galaxy M87 in Virgo and the one at the centre of our galaxy look about the same angular size from Earth. M87 is a long long way away in a cluster of its own. If we collided with M87 or something with a similar heft then I would be then I would be a lot more concerned. M87 has a pretty impressive relativistic jet most of the time with a greed BH.

We will probably be toasted by the sun evolving off the main sequence and swelling up into a red giant before that actually happens. The sun won't have to get too much brighter/bigger before the habitable zone moves away from the Earth.

It will be a close run thing by 6 billion years the Earth's orbit will be just above the surface of the red giant sun - rather toasty.