William Butler Yeats had different beasts in mind, when he first penned the below -- after WWI. That much is certain.
But consider that entirely dark galaxies are out there -- and should you be unlucky enough to miss the gravitational waves, it might just swallow you. . . whole. But fret not -- this one is over 600 million light-years out, in Perseus. We won't fall in -- by anyone's accident or inattention.
"...Things fall apart; the centre cannot hold;
Mere anarchy is loosed upon the world,
The blood-dimmed tide is loosed, and everywhere....
A gaze blank and pitiless as the sun,
Is moving its slow thighs, while all about it
Reel shadows of the indignant desert birds.
The darkness drops again; but now I know
That [six million] centuries of stony sleep
Were vexed to nightmare by a rocking cradle,
And what rough beast, its hour come round at last,
Slouches towards [Perseus] to be born?"
-- William Butler Yeats (1919)
Hah! [Pretty. . . dark, and foreboding -- like our current moment.] Yet, in any event, here's the far more cheerful latest-, and a video- explainer, from NASA (on these stealthy enigmas):
. . .NASA's Hubble Space Telescope has revealed an exceptional discovery in the Perseus galaxy cluster: CDG-2, an ultra-low surface brightness galaxy composed of 99% dark matter.
This elusive galaxy remained hidden until astronomers detected a slight increase in globular cluster density, suggesting the presence of an underlying galactic structure.
Observations from Hubble, ESA's Euclid observatory, and the Subaru Telescope confirmed a faint halo of diffuse light surrounding these ancient star clusters.
Analysis indicates CDG-2 has the luminosity of approximately six million Sun-like stars, with the clusters comprising about 16% of its visible matter. The galaxy's normal matter was likely stripped away through gravitational interactions within the Perseus cluster. . . .
Now you know. . . grin.
नमस्ते





























