— What is a planet ?
The last definition of a planet was adopted by the International Astronomical Union in 2006 . This definition states that a planet must have three characteristics: it must orbit a star (like the Earth orbits the Sun) it must be large enough to have enough gravity to form a sphere . Big enough for its gravity to destroy other similarly sized objects nearby in its orbit around the Sun .
The last definition of a planet was adopted by the International Astronomical Union in 2006 . This definition states that a planet must have three characteristics: it must orbit a star (like the Earth orbits the Sun) it must be large enough to have enough gravity to form a sphere . Big enough for its gravity to destroy other similarly sized objects nearby in its orbit around the Sun .