"MOND holds that for accelerations smaller than an a0 value of roughly 1.2 × 10−10 m/s2, accelerations increasingly depart from the standard M · G / r 2 Newtoni

"MOND holds that for accelerations smaller than an a0 value of roughly 1.2 × 10−10 m/s2, accelerations increasingly depart from the standard M · G / r 2 Newtonian relationship of mass and distance, wherein gravitational strength is proportional to mass and the inverse square of distance. Specifically, the theory holds that when gravity is well below the a0 value, its rate of change—including the curvature of spacetime—increases with the square root of mass (rather than linearly as per Newtonian law) and decreases linearly with distance (rather than distance squared)." [1] I'll bet that in the 20 years a space based experiment can give some data to determine better if MOND is right. [1] https://en.wikipedia.org/wiki/Modified_Newtonian_dynamics https://en.wikipedia.org/wiki/Modified_Newtonian_dynamics See also: https://bigthink.com/starts-with-a-bang/modifying-gravity/ https://bigthink.com/starts-with-a-bang/modifying-gravity/ https://physics.aps.org/articles/v14/143 https://physics.aps.org/articles/v14/143