Two touching each other globular blocks of mass m and radius r each move in a circular orbit around a planet of mass M. The centers of the boulders are located at the same radius, the distance from their point of contact to the center of planet R. With what force does one block press on another? At what radius of the orbit will the mutual attraction of the lumps cease to hold them together? The radius of the planet is R0≫ r. Take the density of the boulders to be equal to the average density of the planet.