I think it is. Take a look at some pictures of Mimas; it looks pretty round to me.
isostasy
Yes, Pluto has been determined to be in hydrostatic equilibrium. Planets must orbit the sun (the first criterion for a planet), and must also be in hydrostatic equilibrium (which Pluto is). Pluto fails the third "planetary entrance test" set by the IAU in that it has not cleared its orbit of debris. A link can be found below to check facts and learn more.
Hydrostatic equilibrium basically means the object has a round shape - spherical if it doesn't spin quickly, in the form of an ellipsoid if it does.Self-gravitation is the mechanism that causes it. It means that all of the parts of the object attract one another.
Mimas has no atmosphere. It does not have enough mass to hold on to one.
One of Saturn's (many) moons is named Mimas.
Hydrostatic and Equilibrium
isostasy
Yes, Pluto has been determined to be in hydrostatic equilibrium. Planets must orbit the sun (the first criterion for a planet), and must also be in hydrostatic equilibrium (which Pluto is). Pluto fails the third "planetary entrance test" set by the IAU in that it has not cleared its orbit of debris. A link can be found below to check facts and learn more.
It must be in direct orbit around the sun (not a moon of another planet) and must have achieved hydrostatic equilibrium (approximately spherical in shape).
Basically it is because of gravity. The technical explanation is called the " principle of hydrostatic equilibrium ".
hydrostatic equilibrium
Hydrostatic equilibrium basically means the object has a round shape - spherical if it doesn't spin quickly, in the form of an ellipsoid if it does.Self-gravitation is the mechanism that causes it. It means that all of the parts of the object attract one another.
Yes, but it varies. One of the requirements for an object to be defined as a planet is for it to have reached hydrostatic equilibrium, meaning it is massive enough for it's gravity to force it into a spherical shape.
The properties of a main-sequence star can be understood by considering the various physical processes occurring in the interior. First is the hydrostatic balance, also called hydrostatic equilibrium. This determines the density structure of the star as the internal pressure gradient balances against the force of gravity.
Mimas tiliae was created in 1758.
Mimas has no atmosphere. It does not have enough mass to hold on to one.
Hydrostatic equilibrium [See related question]