Eris: What's in a name?

Eris, circa 550 BC   (Public Domain)

Eris, that hotly-debated “celestial body” within our solar system which is rightfully named after “the Greek goddess of strife and discord,” is an Eris by many other names.

It is also dubbed “Planet X” (by astronomer Percival Lowell), a “dwarf planet” (by the International Astronomical Union), “Lila” (by Mike Brown of Cal Tech, who referenced a namesake Hindu belief that the cosmos is “the outcome of a game played by Brahma”), and “Xena” (by the 2003 discovery team, that referenced both the “Warrior Princess” and the

previous “Planet X”).

If all this weren’t confusing enough, Eris’ “dwarf planet” categorization has also been a source of contention.  Eris’ discovery forced the IAU in 2006 to hone their definition of just what a planet is.

This IAU definition of a planet now includes the following: “…an object that orbits the Sun, which is large enough to make itself roughly spherical… [and] has enough gravity to force any objects of similar size or that are not under its gravitational control out of its orbit.”

Two out of three ain’t bad, but are nevertheless not enough to call Eris a full-fledged planet by IAU standards.  Since Eris doesn’t have the gravitational clout to qualify, it has been relegated to “dwarf planet” status.

And Pluto?  Don't even ask what a shake-up that’s been…

Resources

http://io9.com/meet-eris-the-solar-systems-largest-dwarf-planet-1707948972

Copyright June 1, 2015 by Linda Van Slyke   All Rights Reserved