In plain language, what is the new definition of planet?
A planet is an object in orbit around the Sun that is large enough (massive enough) to have its self-gravity pull itself into a round (or near-spherical) shape. In addition a planet orbits in a clear path around the Sun. If any object ventures near the orbit of a planet, it will either collide with the planet, and thereby be accreted, or be ejected into another orbit. Q: What is the exact wording of the official IAU proposed definition of planet? A: 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. Q: Does a body have to be perfectly spherical to be called a planet? A: No. For example, the rotation of a body can slightly distort the shape so that it is not perfectly spherical. Earth, for example, has a slightly greater diameter measured at the equator than measured at the pol
