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astronomers seem to have revealed a

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puzzling detail in the way dark matter

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behaves

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they found small dense concentrations of

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dark matter that bend and magnify light

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much more strongly than expected

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dark matter is a mysterious invisible

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substance that makes up the bulk of a

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galaxy the gravitational pull exerted by

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dark matter is thought to tie galaxies

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together throughout the universe there

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is so much regular matter and dark

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matter concentrated in massive galaxy

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clusters that their gravity magnifies

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and warps light from distant background

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objects we call this effect

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gravitational lensing

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we can map where the dark matter is in

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galaxy clusters by observing how the

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light bends

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gravitational lensing distorts the

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appearance of background galaxies into

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deformed shapes and elongated arcs

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pictures of lensing galaxy clusters are

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filled with the smeared images of remote

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background galaxies

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the higher the concentration of dark

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matter in a galaxy cluster the more

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dramatic its light bending power is

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smaller clumps of dark matter associated

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with individual galaxies in the galaxy

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cluster create more distortions

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in some sense the galaxy cluster acts as

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a large lens that has many smaller

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lenses embedded inside of it but

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strangely astronomers found that three

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galaxy clusters used in their study had

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concentrations of dark matter that are

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so massive that the lensing effects they

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produce are 10 times stronger than

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originally expected

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hubble's crisp images coupled with

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observations from the very large

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telescope in chile helped astronomers

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produce a more accurate dark matter map

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by measuring the lensing distortions

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astronomers could trace out the amount

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and distribution of dark matter

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this recent study could signal a gap in

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our current understanding of the nature

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of dark matter and its properties

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it shows us that there's clearly a

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missing feature of the real universe

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that we simply are not capturing in our

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current theoretical models

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with studies like this astronomers look

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forward to continuing to pin down the

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intriguing nature of dark matter to