ˈrȯsh-, ˈrōsh- noun
or roche's limit -shə̇z-
Usage: usually capitalized R
Etymology: after E. A. Roche died 1833 French mathematician
: the distance between a planet's center and its satellite within which the satellite cannot approach without suffering disruption ; specifically : the distance 2.44 times the planet's radius from its center when the planet and the satellite are of the same density