Tidal disruption near a massive primary

What you are seeing: a cloud of 80 self-gravitating particles ("a fluid satellite") on an eccentric orbit around a heavy primary. As the cloud sweeps inward, the primary's tidal field pulls on the near side harder than the far side. If the satellite's own gravity is weak enough (the "cohesion" slider), tides win and the cloud stretches into a long stream. If cohesion is strong, the cloud stays packed.

The Roche limit for an equal-density fluid satellite is $r_R \approx 2.44\,R_\text{primary}$. Below this radius a fluid moon cannot hold itself together. Famous example: Saturn's rings sit inside the Roche radius of Saturn, which is why no large moon has ever formed there.