Assertion: planetary mass moon | /r/AtLocation | case
Facets:
Source sentences:
text: In addition, the IAU definition of 'hydrostatic equilibrium' is quite restrictive – that the object's mass be sufficient for gravity to overcome rigid-body forces to become plastic – whereas planetary-mass moons may be in hydrostatic equilibrium due to tidal or radiogenic heating, in some cases forming a subsurface ocean.