Eris: Plutoid, Dwarf Planet, or 10th Planet?

Eris was discovered on January 5, 2005 by Michael E. Brown, Chad Trujillo, and David A. Rabinowitz. Its orbit is more eccentric and more highly inclined than Pluto’s, and it is almost as large as Pluto, having a diameter that is 97.9% that of Pluto. Eris last came to perihelion on July 23, 1699 when it was in the constellation Virgo shining at a magnitude of 14.8, well beyond the reach of any telescopes existing at the time.

Pluto, Eris, and Satellites – Sizes and Orbital Distances to Scale

Eris has an orbit that is so eccentric (e = 0.44) that it actually spends some time each orbit closer to the Sun than Pluto is during the outer reaches of its orbit. Pluto’s aphelion distance is 49.31 AU, and Eris will be closer to the Sun than that for 99 years, from 2208 to 2307.

Eris is closer to the Sun than Pluto’s average distance of 40.70 AU for 43 years, between 2236 and 2279. Eris again reaches perihelion in 2257, when it will be 38.09 AU from the Sun.

Eris has an orbit that is tilted at nearly a 45° angle with respect to the ecliptic. This takes it through some interesting constellations during its 559-year orbital period. Here is its upcoming travel itinerary.

Upcoming Travel Plans for Eris (not subject to change1)

2022   Cetus
2036   Pisces
2059   Cetus
2064   Aries
2126   Perseus
2174   Camelopardalis
2197   Lynx
2208   Ursa Major
2237   Canes Venatici
2245   Coma Berenices
2256   Virgo
2274   Libra
2281   Hydra
2285   Centaurus
2286   Lupus
2298   Norma
2308   Ara
2320   Pavo
2357   Indus
2367   Tucana
2376   Grus
2399   Phoenix
2434   Sculptor
2487   Cetus

1 Unless the constellation boundaries are redrawn due to precession or other considerations

In Greek & Roman mythology, Eris is the goddess of strife and discord. 500 years hence, in 2522, Eris will once again be in Cetus, as it is today. But where will we be? What kind of life will our great-great-great-great great-great-great-great-great-great-great-great-great great-great grandchildren have in 2522? Here are some of my hopes for 2522.

  • Humanism will have replaced religion.
  • There will be no poverty in the world.
  • Everyone will have adequate health care, and it will be free.
  • Zero population growth will have been achieved by the only humane way possible: having fewer children.
  • There will be no more wars, no weapons of mass destruction.
  • There will be no need for guns, and no one will have them.
  • Violence will not be tolerated, nor will society glorify it or dwell on it in any way.
  • Individuals who “cross the line” and violate others through the use of physical violence will be psychologically re-engineered so they will live productive and fulfilling lives without being a threat to others. This neutralization of violent tendencies must be accomplished humanely and in a way that does not violate the individual’s essential humanity.
  • The Earth will be treated as the oasis it is.
  • Money will no longer exist, nor will it be needed.

Though no one alive today is likely to ever see any of these things, that in no way excuses us from working substantially towards these goals. To do anything less is a dereliction of moral duty.

Leave a Reply

Your email address will not be published. Required fields are marked *