Our clusters are shedding!
Astronomers have observed 11 runaway galaxies wandering aimlessly around in spaaace. The discovery was revealed by star-gazing boffin Igor Chillingarian of Harvard-Smithsonian Center for Astrophysics (HSCA) and Moscow State University, who was the lead author of a study published in the Science journal on Friday. Scientists …
I reckon I'd struggle a bit to ever reach "More than a million miles per hour", but I reach speeds of "Up to 6 million miles per hour" every day without breaking a sweat.
Tip - Whenever you see it, always substitute the phrase "up to" with "less than". It means the same and you're far less likely to emerge from the New Year sales with heaps of unwanted and overpriced tat.
Unfortunately the article is paywalled. But reading this piece it seems to be saying that that IF these galaxies escaped from an averagely central position in an average cluster then the escape velocity would need to be about such and such.
But if you don't know where they've come from, then how can you tell if this has actually happened or not?