By sciencebase, Section News Posted on Tue Aug 19, 2008 at 10:51:54 PM PST
Mark Sykes says that if a non-stellar object is massive enough to be almost spherical and it orbits a star, then it ought to be called a planet. With this definition the solar system will become a 13-planet system.
By Sykes criteria, the smallest known planet in the solar system would be Ceres, the largest and most massive object in the asteroid belt. Ceres is less than half the diameter of Pluto.
Sykes, director of the Planetary Science Institute is talking about planets across the universe in general, about Pluto and other small
planets in particular, and about planets in the distant reaches of our solar system yet to be discovered. Some of those could even be as large
as the Earth, he claims.
