by New research shows that some star clusters don’t obey Newton’s theory of gravity. The researchers analyzed data collected by the ESA Gaia mission to calculate each star’s speed, direction of motion and age. It turned out that as the cluster disintegrated, the stars gathered on two tidal tails, one in front of the cluster and one behind. According to Newton’s law of gravity, the likelihood of stars appearing in a tidal tail is similar, that is, the number of stars on both tidal tails should be roughly the same. But research shows that this is not the case, and the tidal tails in front of the cluster always contain more stars. Instead of Newtonian gravity, the results were more in line with a controversial theory called Modified Newtonian Dynamics (MOND).
