Astronomy

Nope. MOND is not the answer. It is never going to be the answer. There are too many things that MOND cannot explain. One of the reasons why planet 9 was hypothesized to exist is because the orbits of objects far from the sun are out of plane in weird highly elliptical orbits not explainable through modification of gravity's effects at small force scales. Dark matter is another phenomenon MOND was meant to explain away but cant. i.e the bullet cluster is an object with less than 1% of its mass accountable by visible matter. MOND cannot make up the difference. Structures like this are only explainable if dark matter actually exists. The best MOND can hope for is to account for some but not all, of the discrepancy.