R_L stands for roche limit, G stands for gravitational constant, M stands for the mass of the central celestial body, and R stands for the distance from the celestial body to the central celestial body.
The so-called roche limit is the most extreme danger zone when a small celestial body approaches a large celestial body. As long as they reach this zone, small celestial bodies will be torn to pieces by the gravitational tide of large celestial bodies.
The meaning of Roche limit:
The Roche limit, also known as the Roche radius, is the smallest possible distance between a planet and its satellite. Less than this distance, the tidal action of the planet on the satellite will lead to the disintegration of the satellite. It is also commonly used in binary star systems. This critical radius was calculated by French mathematician edouard roche in 1848, so it is called Roche limit.
The matter in the roche limit is greatly influenced by planetary tides. Although the particles in the ring will collide, the tidal force is still greater than its own gravity, so it can't gather into a satellite and form a ring system. Outside the limit, substances tend to merge, and small particles will stick together and grow up under the influence of each other's gravity. The formation of planetary rings is closely related to roche limit. Because of this, it is often the heavier planets that have stable planetary rings.