Update your maps, dictionaries and sci-fi dialogue

Formerly considered to be the largest asteroid, Ceres is now the 5th planet from the sun.

I said it would happen, and now it has. Astronomers have redrawn the map of the solar system to account for newly discovered objects in the Kuiper belt that are larger than Pluto.

Our new solar system includes, at the moment, 12 planets. The traditional 9, plus Charon, Ceres and an as-yet unnamed body provisionally called UB313. However, there are a dozen others under immediate consideration and astronomers predict that there could be hundreds (scroll down to “Tally would soar”) that would qualify.

The solution includes the designation of new types of celestial bodies and new definitions for old terms.

The new, official definition of a planet is any “celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet.”

Additionally, astronomers invented a new term, pluton, which means any planet with an orbit that takes more than 200 Earth years to complete.

Finally, two unofficial terms seem likely to become widespread: Dwarf planets are those smaller than Mercury, including Pluto and all the new entries, while Classic planets are the 8 large bodies traditionally called planets before the discovery of Pluto.

The changes are expected to become official on August 24 with a confirmation vote at the International Astronomical Union General Assembly.

Got that?

For kicks, and since heaven knows this entry could use some more links, here are a couple of handy infographics showing the largest known Kuiper belt objects and the 3 new planets already confirmed.

Tags: space