The proposal refines current definitions that require planets to be round bodies which orbit our sun and have ‘cleared’ their neighbourhoods Planetary scientists are proposing a new definition for ...

The International Astronomical Union defines a planet as a celestial body that orbits the sun, is massive enough that gravity has forced it into a spherical shape, and has cleared away other objects ...

Three astronomers last week proposed expanding the official definition of a planet to encompass worlds orbiting stars other than our own, a nuance not currently included in the formal definition of ...

The official definition of a “planet” could be set to change again soon. Last time that happened, Pluto was kicked out of the club, but the new proposed definition is designed to be more inclusive.