Behold: the Cheshire Cat galaxy group in the constellation of Ursa Major – apparently grinning happily at us from 4.6 billion light years away. To wit:

Albert Einstein’s general theory of relativity, published over 100 years ago, predicted the phenomenon of gravitational lensing. And that’s what gives these distant galaxies such a whimsical appearance, seen through the looking glass of X-ray and optical image data from the Chandra and Hubble space telescopes. Nicknamed the Cheshire Cat galaxy group, the group’s two large elliptical galaxies are suggestively framed by arcs. The arcs are optical images of distant background galaxies lensed by the foreground group’s total distribution of gravitational mass. Of course, that gravitational mass is dominated by dark matter. The two large elliptical “eye” galaxies represent the brightest members of their own galaxy groups which are merging. Their relative collisional speed of nearly 1,350 kilometers/second heats gas to millions of degrees producing the X-ray glow shown in purple hues

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3 thoughts on “Gravity’s Grin

  1. Spaghetti Hoop

    Ah here, just watched Neil Armstrong’s biopic online and I’m Buzz-in. This astronomical photography and galaxy data right now is incredible. I have so many other gravitational pulls but if they taught this stuff to school kids, prisoners as well as academics, we could have a really broadly-dispersed knowledge of space over the next decade.

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