The dwarf planet Haumea has an ellipsoidal shape due to its rapid rotation. It is one of the few known objects in the solar system that has a highly elongated shape. Several factors contribute to its non-spherical shape:
Rotation: Haumea rotates on its axis very rapidly, completing a full rotation in about four hours. This rapid rotation creates a centrifugal force that counteracts the force of gravity, causing the planet to bulge at the equator and flatten at the poles. This effect is known as oblateness and is responsible for the ellipsoidal shape.
Tidal forces: Tidal forces from other celestial bodies, such as its moons or close encounters with other objects, can also influence the shape of a celestial body. These forces can cause distortions and affect the equilibrium shape of an object, leading to deviations from a perfect sphere.
Internal composition: Haumea's internal composition could also contribute to its non-spherical shape. If it has a non-uniform distribution of mass or variations in density, it can result in an uneven gravitational field, leading to the deformation of its shape.
It's important to note that the shape of a celestial body is determined by a balance between gravitational forces, internal properties, and external influences. In the case of Haumea, its rapid rotation is the primary factor shaping its ellipsoidal form.