today is that the forces in galaxies do not seem to add up. Galaxies rotate much faster than predicted by applying Newton’s law of gravity to their visible matter, despite those laws working well everywhere in theis needed. This is why the idea of an invisible substance called dark matter was first proposed. But nobody has ever seen the stuff.
This means that, although Mond effects would typically kick in several thousand light years away from a galaxy, if we look at an individual star, the effects would become highly significant at a tenth of aand the Sun. But weaker Mond effects should also be detectable at even smaller scales, such as in the outerat 10 AU. Due to a quirk of Mond, the gravity from the rest of our galaxy should cause Saturn’s orbit to deviate from the Newtonian expectation in a subtle way.
With the standard assumptions considered most likely by astronomers and allowing for a wide range of uncertainties, the chance of Mond matching the Cassini results is the same as a flipped coin landing heads up 59 times in a row. This is more than twice the “5 sigma” gold standard for a discovery in science, which corresponds to about 21 coin flips in a row.should orbit around each other 20% faster than expected with Newton’s laws.