There should be many more dwarf galaxies that have yet to be discovered and that are hiding at large distances from the Milky Way center, observed Tobias K. Fritz, a researcher at the Instituto de Astrofísica de Canarias (IAC).
An international group of astronomers has revived a previously debunked theory of gravity, arguing that motions within dwarf galaxies would be slower if close to a massive galaxy. The theory, MOND, is a controversial alternative to general relativity, the prevailing Einstein-inspired understanding of the phenomenon of gravity, that requires dark matter to exist, but this has never been proved. MOND does not require dark matter.