In one corner is dark matter, a strange form of matter that surrounds galaxies, and can be seen only through its gravitational tug on light. Overall, it's predictions agree with dwarf galaxies better than dark matter, and MoND also matches the rotation of spiral galaxies. As long as direct detection of dark matter continues to elude us, modified gravity models will be eager challengers. This is exactly what one would expect from MoND models, and seemed to go against the predictions of dark matter. So dark matter can account for the rotational dynamics of a galaxy just as MoND models can.

Source: Forbes April 25, 2017 18:22 UTC