That Troublesome Minx Eris is Discovered

That Troublesome Minx Eris is Discovered July 29, 2015

eris

It was on this day in 2005 that Eris was discovered by a Palomar Observatory team led by Mike Brown. At first it appeared to be larger than Pluto (turns out that it has greater mass, but Pluto has a slightly larger diameter.) and was announced by NASA as the tenth planet. This sparked the conversations among the members of the International Astronomical Union that led to the new designation “dwarf planet” for these smaller spherical objects circling the sun, including as a result Pluto’s notorious “demotion.”

While all the kerfuffle around planet or something else, and then with different ways of coming up with names it was informally called Xena (the warrior princess) for the then popular television character. When finally designated a dwarf planet Xena became Eris. Appropriate as Eris is the Greek goddess of chaos, strife and discord. It has a single moon, Dysnomia, which means lawlessness, named for the Greek goddess Eris’ daughter.

Eris and its moon are the farthest out known natural objects within the solar system, It takes Eris 558 years to circle the sun. Like Pluto it has an eccentric orbit well out of the plane the major planets mostly rest upon. At its farthest it is 97.65 astronomical units from the sun, at its closest 37.91 AU, meaning it slips inside of Pluto’s orbit.

All in all, a trouble maker up there in the heavens.


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