Dwarf Planet Eris, formerly known as 'Xena' |
Dwarf Planet Eris, formerly known as 'Xena' |
Sep 15 2006, 03:53 PM
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#16
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Senior Member Group: Members Posts: 1592 Joined: 14-October 05 From: Vermont Member No.: 530 |
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. |
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Sep 15 2006, 04:02 PM
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#17
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Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
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 -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Sep 15 2006, 05:09 PM
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#18
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Senior Member Group: Members Posts: 2454 Joined: 8-July 05 From: NGC 5907 Member No.: 430 |
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.... -------------------- "After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance. I see that such intercourse long continued would make one thoroughly prosaic, hard, and coarse. But the longest intercourse with Nature, though in her rudest moods, does not thus harden and make coarse. A hard, sensible man whom we liken to a rock is indeed much harder than a rock. From hard, coarse, insensible men with whom I have no sympathy, I go to commune with the rocks, whose hearts are comparatively soft." - Henry David Thoreau, November 15, 1853 |
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Sep 15 2006, 06:33 PM
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#19
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Member Group: Members Posts: 249 Joined: 11-June 05 From: Finland (62°14′N 25°44′E) Member No.: 408 |
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... -------------------- The universe is not only stranger than we imagine, it is stranger than we can imagine.
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Oct 7 2007, 06:20 PM
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#20
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Newbie Group: Members Posts: 5 Joined: 17-January 06 Member No.: 647 |
Would a mission to Eris be possible? Is anybody talking about it?
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Oct 7 2007, 08:52 PM
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#21
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Senior Member Group: Members Posts: 1887 Joined: 20-November 04 From: Iowa Member No.: 110 |
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.
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Oct 7 2007, 10:33 PM
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#22
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Senior Member Group: Members Posts: 1018 Joined: 29-November 05 From: Seattle, WA, USA Member No.: 590 |
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 |
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Oct 8 2007, 04:03 AM
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#23
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Newbie Group: Members Posts: 10 Joined: 10-January 06 From: Syracuse, NY, USA Member No.: 641 |
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. |
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Oct 8 2007, 04:22 AM
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#24
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Senior Member Group: Members Posts: 1870 Joined: 20-February 05 Member No.: 174 |
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.
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Oct 8 2007, 05:22 AM
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#25
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
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. |
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Aug 12 2008, 03:13 PM
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#26
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Senior Member Group: Moderator Posts: 2262 Joined: 9-February 04 From: Melbourne - Oz Member No.: 16 |
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.) -------------------- |
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Nov 19 2008, 09:33 PM
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#27
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Senior Member Group: Moderator Posts: 2785 Joined: 10-November 06 From: Pasadena, CA Member No.: 1345 |
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 -------------------- Some higher resolution images available at my photostream: http://www.flickr.com/photos/31678681@N07/
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Oct 27 2011, 07:51 AM
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#28
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Member Group: Members Posts: 241 Joined: 16-May 06 From: Geneva, Switzerland Member No.: 773 |
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. |
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Oct 27 2011, 08:53 AM
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#29
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Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
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 |
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