PUBLISHED: 16:31, Sat, Sep 12, 2020 | UPDATED: 16:31, Sat, Sep 12, 2020
Dark matter cannot be seen and it cannot be interacted with in any meaningful way scientists know of. But the existence of the mystery substance has been inferred from the movements of spinning galaxies, which instead of flying apart, are bound together by an unseen source of gravity. Even more astonishingly, there is so much dark matter in the Universe, it accounts for about 27 percent of it.
For comparison, normal or baryonic matter - the kind from which everything we can touch and see is made of - only accounts for less than five percent of the Universe.
Consequently, physicists have explored a wide range of theories explaining the nature of dark matter, including suggestions it is gravity leaking into our Universe from another dimension.
But not all is as it seems, thanks to new observations made by NASA's Hubble Space Telescope.
Scientists have discovered an unusual mismatch between the theoretical models of how dark matter should be distributed in galaxy clusters and how it seems to behave.
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Dark matter mystery: A new dark matter study has counfounded scientists (Image: GETTY)
Dark matter mystery: Dark matter concentrations cause gravitational lensing (Image: NASA)
In a new paper published this week (September 11), scientists outlined how small-scale concentrations of dark matter in galaxy clusters produce gravitational lensing effects 10 times stronger than expected.
Gravitational lensing occurs when a source of gravity is powerful enough to bend the fabric of space itself - spacetime - causing light passing nearby to swerve.
And galaxy clusters are the largest hoards of dark matter in the Universe, holding hundreds to thousands of individual galaxies bound together by gravity.
Clusters hold dark matter on a large scale as well as on a smaller one within all of their individual galaxies.
Massimo Meneghetti of the INAF (National Institute for Astrophysics)-Observatory of Astrophysics and Space Science of Bologna in Italy, the study's lead author, said: "Galaxy clusters are ideal laboratories to understand if computer simulations of the Universe reliably reproduce what we can infer about dark matter and its interplay with luminous matter.