SOLAR SYSTEM

Detailed explanation-1: -A planet is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

Detailed explanation-2: -A planet is a large object that orbits a star. To be a planet, an object must be massive enough for gravity to have squeezed it into a spherical, or round, shape, . It must also be large enough for gravity to have swept up any rocky or icy objects from its path, or orbit, around the star.

Detailed explanation-3: -Dwarf planets are a lot like regular planets: They both have enough mass and gravity to be nearly round-unlike odd-shaped asteroids. They both travel through space in a path around the Sun.

Detailed explanation-4: -Pluto is the largest known body in the Kuiper Belt with enough mass to exhibit a spherical shape. Even though Pluto has enough mass to give it a spherical shape, Pluto is in fact smaller in physical size than seven of the solar system’s moons, including Earth’s.

Detailed explanation-5: -The Sun and all eight planets of the solar system are round. Why? The gravitational force of a planet’s mass pulls all of its material toward the center, smoothing out any jarring non-roundness. Many of the smaller bodies of the solar system are not round because their gravity is not enough to smooth out their shape.