Definition of Roche limit in English:

Share this entry

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.

Share this entry

What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.