Question

What effect does hydrostatic equilibrium have on a solar system body

Answer 1

To attain spherical shape is the  hydro-static equilibrium have on a solar system body

Explanation:

The interior of the sun has hydrostatic equilibrium which keeps the sun stable. It helps to maintain equilibrium between the gravitational force and the force exerted due to the gas. The gravitational pull creates inward force to destabilise the sun. But the gases creates outward pressure.  

These two forces acting against each other give a spheroidal shape for the planets.The static structure of the solar system body is obtained by the hydrostatic equilibrium and not giving room to shrink or expand its state.