Free Astronomy Magazine January-February 2021

24 JANUARY-FEBRUARY 2021 ASTRO PUBLISHING haves. This missing ingredient may explain why researchers have un- covered an unexpected discrepancy between observations of the dark matter concentrations in a sample of massive galaxy clusters and theo- retical computer simulations of how dark matter should be distributed in clusters. The new findings indi- cate that some small-scale concen- trations of dark matter produce lensing effects that are 10 times stronger than expected. Dark mat- ter is the invisible glue that keeps New light shed on small-scale concentrations of dark matter O bservations by the NASA/ ESA Hubble Space Telescope and the European Southern bservatory’s Very Large Telescope (VLT) in Chile have found that something may be missing from the theories of how dark matter be- by NASA/ESA