Definition of Roche limit in English:

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Roche limit

Pronunciation: /rəʊʃ/
(also Roche's limit)


The distance within which the gravitational field of a large body is strong enough to prevent any smaller body from being held together by gravity.
Example sentences
  • Amalthea is not a rigid body, being inside the Roche limit; but its gravity is more than adequate to hold it together, being 6 times stronger than the forces pulling it apart.
  • At a certain distance near a planet, known as the Roche limit, an object can be literally pulled apart by gravity.
  • Phobos has a number of interesting surface features, including grooves that could be created by the gravity gradient of Mars - Phobos is within Mars's Roche limit - trying to tear the moon apart.


Late 19th century: named after Edouard Albert Roche (1820–83), French mathematician.

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