Pluto: Dwarf Planet

From young, we have learned that the Solar System has nine planets. Now, with the new classification of Dwarf Planet, the Planet Family has only eight members.

When the New Horizons Spacecraft reaches Pluto in 2015, its destination is no longer a planet.

A dwarf planet, as defined by the International Astronomical Union (IAU), is a celestial body orbiting the Sun that is massive enough to be spherical as a result of its own gravity but has not cleared its neighboring region of planetesimals and is not a satellite. More explicitly, it has to have sufficient mass to overcome its compressive strength and achieve hydrostatic equilibrium.

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