“This is the most colossal cosmic smash-up ever witnessed in the universe” says New Scientist:
A bundle of galaxies, nicknamed Pandora’s cluster, turns out to be the result of a violent crash between at least four separate galaxy clusters that lasted hundreds of millions of years…
The splattered remains suggest several galaxy clusters have collided over about 350 million years. Bright visible galaxies make up 5 per cent of the mass, while searingly hot gas that glows in X-rays makes up 20 per cent. The rest is dark matter, a mysterious invisible substance that gives itself away only because its gravity bends light from background galaxies.
“See there, wouldn’t want to be there,” says David Klaus:
It’s a rough clue to what we’re going to look like when Andromeda hits the Milky Way in about three billion years. Depending on where it is in its galactic orbit the Solar System will either be eaten by the giant multiple black hole as the galactic centers merge, or flung out of the galaxy completely.
That would be bad.
[Thanks to David Klaus for the story.]