Dwarf Planet Eris, formerly known as 'Xena' Options

[SigurRosFan]

Here's the official name of the 'Xena' ...

Eris: 'Xena' (2003 UB313, 136199)

Eris I or Dysnomia: 'Gabrielle'

[SigurRosFan]

Sources:

- http://cfa-www.harvard.edu/iauc/RecentIAUCs.html

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IAUC 8747 (2006 Sept. 13)

* (134340) PLUTO, (136199) ERIS, AND (136199) ERIS I (DYSNOMIA)
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- http://cfa-www.harvard.edu/iau/special/08747.pdf (IAU Circular PDF)

[Jyril]

Eris is the personification of strife and Dysnomia is the goddess of anarchy and disobedience.

[Jyril]

Oh, and the Roman counterpart (actually translation) of Eris is Discordia. According to the Wikipedia, the character Discord in the Hercules and Xena television series is based on her.

[volcanopele]

Eris is the personification of strife and Dysnomia is the goddess of anarchy and disobedience.

Very appropriate!

[David]

So it was Eris that threw the golden apple of 2003 UB313 amongst the astronomers, to incite them to strife and contention over the definition of a planet...

[dvandorn]

I seem to recall that Brown, et. al., were holding off on announcing the "real" names of their discoveries until after it was determined whether or not 'Xena' would be considered a planet. Something about planet naming conventions vs. TNO naming conventions.

So -- does anyone know, are these names the TNO versions of the names they had in mind? Or were they looking at these names all along?

-the other Doug

[JRehling]

My very eager mother just started using non plastic earrings.

It's a planet to me. Civil disobedience as is necessary.

[mcaplinger]

So -- does anyone know, are these names the TNO versions of the names they had in mind? Or were they looking at these names all along?

I seem to remember reading around the time that Quaoar was named that a general naming source for KBOs was going to be non-western creation myths, but I can't find that reference at the moment (Mike Brown's web pages have all been updated since then.)

Frankly, if these names reference the IAU debacle, then they are a little too whimsical for my taste.

[alan]

Nice name, the group responsible for approving names must have a sense of humor. Who would have expected that.

[Jyril]

Space.com:

Eris' discoverer, Michael Brown of the California Institute of Technology, said the name was an obvious choice, calling it "too perfect to resist.''

[lyford]

As the Bad Astronomer points out:

The moon of Eris, formerly known as Gabrielle, is now Dysnomia, the goddess of lawlessness.
Mind the pun here: Xena was played by Lucy Lawless! Man, that’s funny. That must have been on purpose. I’ll have to track that down.

That's a great story, but may be too good to be true....

[Guest_Myran_*]

lyford wrote: That's a great story, but may be too good to be true....

Actually I do think the name have been chosen for the connection to that Xena - an in joke.
Just like the two first letter of the name Pluto gets the initials of Percival Lowell.

[Jyril]

SkyTonight.com:

The satellite, now called Dysnomia, is named for Eris's daughter, the goddess of lawlessness — a tribute, says Brown, to the actress who played Xena, Warrior Princess: Lucy Lawless. But Brown is quick to point out that the moon also follows another tradition for "dwarf planet" satellite names: Pluto's moon Charon was discovered in 1978 by James W. Christy, and the first syllable in Charon matches the first syllable in Christy's wife's name, Charlene. Brown's wife's name is Diane. "We're going to call the moon Di," says Brown.

[dvandorn]

Nice name, the group responsible for approving names must have a sense of humor. Who would have expected that.

Both I and my roommate are pagan -- he's a Druid and I'm a Wiccan -- and when we heard the names they chose for 'Xena' and 'Gabrielle,' we were floored! I mean, there are certain groups who refuse to even speak those names (or the names of similar gods of discord and mischief from other pantheons), as just their mere mention, it is thought, can invite that discordant energy into one's life... It's sort of like going into the Harry Potter universe and naming a new planet 'Voldemort,' if you know what I mean.

However, as a jibe at the discord that the current "debate" has engendered in the astronomical community, I think they're absolutely perfect!

-the other Doug

[stevesliva]

It's sort of like going into the Harry Potter universe and naming a new planet 'Voldemort,' if you know what I mean.

So you've got me searching the minor planet names list:
http://cfa-www.harvard.edu/iau/lists/MPNames.html

There is a "(1930) Lucifer." There must be some others in there.

Actually, I'm surprised by the dearth of "evil" names. I'd love to name some asteroids War, Famine, Pestilence and Death.

[dvandorn]

Here's one from that list that caught my eye:

(25924) Douglasadams

If that's a NEO, maybe, at some time in the far future, it *will* be time for the dolphins to say "So long, and thanks for all the fish"...

-the other Doug

[ljk4-1]

So you've got me searching the minor planet names list:
http://cfa-www.harvard.edu/iau/lists/MPNames.html

There is a "(1930) Lucifer." There must be some others in there.

Actually, I'm surprised by the dearth of "evil" names. I'd love to name some asteroids War, Famine, Pestilence and Death.

I've heard that Mars has two moons with names like that....

[Jyril]

Here's one from that list that caught my eye:

(25924) Douglasadams

If that's a NEO, maybe, at some time in the far future, it *will* be time for the dolphins to say "So long, and thanks for all the fish"...

-the other Doug

It is a regular asteroid. But look at its provisional designation, 2001 DA42: 2001 is the year of his death, DA his initials and 42...

The name of the asteroid (18610) Arthurdent was supposedly published on the day of his death. However, the name was actually published a few days earler. A sick quirk of fate anyway...

[yg1968]

Would a mission to Eris be possible? Is anybody talking about it?

[alan]

Eris is currently 97 AU from the sun. It took Voyager 1, currently the most distant functioning probe, nearly 30 years to reach that distance. NASA probably would have to develop some new propulsion technology before a mission to Eris would be considered.

[Greg Hullender]

Dawn manages an acceleration of 7 m/s/d or about 81 microns/sec^2. :-) If it could accelerate full-time half-way to Eris and then decelerate full-time the other half, I figure it'd take under 70 years. However, if we could kick that up to 50 m/s/d, then it'd take right at 10 years.

(Someone should double-check these figures before launching their own mission, of course.) :-)

--Greg

[dvanavery]

Eris is currently 97 AU from the sun. It took Voyager 1, currently the most distant functioning probe, nearly 30 years to reach that distance. NASA probably would have to develop some new propulsion technology before a mission to Eris would be considered.

Yes, but the Voyager trajectories were formulated with something other than raw speed to the outer Kuiper belt in mind. I'm not saying that new propulsion tech wouldn't be needed, but I would bet something substantially faster than V1 could be sent using present day tech (and some well timed flybys of outer planets along the way). You might have to wait a decade or five for the proper alignment to reach Eris, though.

this brings up an interesting question, what is the fastest possible solar system escape velocity possible using only presently available launch vehicles and gravitational assists from th outer planets? Assume you have an RTG-powered mission of some useful mass (300-500kg, no ion thrusters of any kind, no solar sails..........), basically a New Horizons clone, and no new propulsion tech. What's the theoretical maximum? There are probably once-in-a-millennium alignments of Jupiter and Saturn that would allow for speeds well in excess of anything we've sent so far. Someone has to have done a simulation at some point......

-dave V.

[edstrick]

Probably some perfect "grand tour" type alignment, where each spacecraft-planet encounter is as close-in to the planet as possible for a departure trajectory that's approximately tangent to the planet's orbit or as close to tangent as possible.

[JRehling]

Probably some perfect "grand tour" type alignment, where each spacecraft-planet encounter is as close-in to the planet as possible for a departure trajectory that's approximately tangent to the planet's orbit or as close to tangent as possible.

Eris is also well off of the ecliptic at present (and for a long time coming). I doubt that keeping things in the ecliptic for three flybys then counting on Neptune to provide all of the work to acquire a high inclination is feasible. Maybe a Jupiter-Saturn combo could do it, assuming the rings weren't a problem.

That would actually be a scenario that would unfold fairly often.

Uranus is actually in a pretty good position right now for an assist to Eris, but it'll soon move out of that good position and not come back for 8 decades. Neptune, however, is moving into position, but again, Neptune can't bend the path down in very good proportion to Jupiter's bending it out.

In only 230 years or so, Eris will come within 40 AU of the Sun. Let's plan on an Eris Orbiter/Lander then. Start the buzz now.

[jamescanvin]

Moved posts to a new thread The Great Planet Debate conference

Will make it easier to close when the arguments start (I hope i'm wrong, play nice.)

[Juramike]

Eris has weather!

space.com article about seasonal atmospheric ices transfer on Eris: http://www.space.com/scienceastronomy/0811...arf-planet.html

Nitrogen sublimates first, then deposits first on the colder pole.
Methane sublimates next, then deposits on top of nitrogen on the colder pole.

If I understand this correctly, the layering would be unstable, with the more volatile (nitrogen woofs off at a lower temperature) component buried under the methane layer.

Could make some really impressive nitrogen jets through the methane ice surface during the spring "warm up".

-Mike

[MarcF]

In the journal Nature from today:

"A Pluto-like radius and a high albedo for the dwarf planet Eris from an occultation
B. Sicardy et al.
The dwarf planet Eris is a trans-Neptunian object with an orbital eccentricity of 0.44, an inclination of 44 degrees and a surface composition very similar to that of Pluto. It resides at present at 95.7 astronomical units from Earth, near its aphelion and more than three times farther than Pluto. Owing to this great distance, measuring its size or detecting a putative atmosphere is difficult. Here we report the observation of a multi-chord stellar occultation by Eris on 6 November 2010 ut. The event is consistent with a spherical shape for Eris, with radius 1,163 ± 6 kilometres, density 2.52 ± 0.05 grams per cm3 and a high visible geometric albedo. No nitrogen, argon or methane atmospheres are detected with surface pressure larger than ~1 nanobar, about 10,000 times more tenuous than Pluto's present atmosphere. As Pluto's radius is estimated to be between 1,150 and 1,200 kilometres, Eris appears as a Pluto twin, with a bright surface possibly caused by a collapsed atmosphere, owing to its cold environment. We anticipate that this atmosphere may periodically sublimate as Eris approaches its perihelion, at 37.8 astronomical units from the Sun."

Cheers,
Marc.

[Paolo]

I just read the Nature paper. Eris is quite an interesting object.
a few notes:

- Eris is probably a rocky body with an icy crust. its density is quite higher than that of Pluto (almost 30 p.c.) and of other KBO but compatible with that of Makemake.
- Eris is one of the brightest objects in the solar system. its albedo is 0.96. only Enceladus has a greater albedo

too bad I fear none of us will be around when Eris gets its first visit