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Enigma of Uranus solved at last
Yahoo! News ^
| 3/10/04
| AFP - Paris
Posted on 03/10/2004 10:47:40 PM PST by NormsRevenge
PARIS (AFP) -
Uranus has puzzled scientists ever since the probe Voyager 2 did a flyby in 1986 and found that its magnetic field appeared to break the planetary rulebook.
The evidence from Earth, Jupiter and Saturn determined that a planet's magnetic field should be like that of a bar magnet, with a north and south pole that runs roughly along the sphere's rotational axis.
But Uranus -- and Neptune, too, Voyager found -- are radically different.
Their magnetic fields are tipped over (the north-to-south line lies midway to the equator or even closer) and there are two north and two south poles, as if the field were produced by two bar magnets.
The reason for this, according to a new theory published on Thursday in the British journal Nature: The underlying structures of Uranus and Neptune are radically different from what was previously assumed about these cold, distant planets.
Planetary magnetic fields are created like a dynamo: beneath the planet's surface, there is an electrically conductive fluid, which is driven around by an energy source.
In the case of Earth, for instance, the planet's solid inner core is bathed in a molten iron-rich fluid, which is propelled around by the planet's rotation and by convection currents, which transfer heat from the core toward the surface.
And in Jupiter and Saturn, which are "gas giants" rather than rocky planets like Earth, the magnetic field is believed to derive from a thick layer of sub-surface hydrogen, compressed by gigantic pressures into an electric soup of protons and electrons, which revolves around a small solid core.
Where Neptune and Uranus differ, the new study says, is that even though they are gas giants, their interior structure is different from those of Jupiter and Saturn.
It suggests that these two outer planets may have only a thin layer of metallic convecting fluid.
This has a big effect on the magnetic field, limiting it to a thin "shell" just under the gassy hydrogen surface. That phenomenon may also cause the field to be tipped on its side compared to the rotational axis and also inflict the "quadrupole" effect.
The study's co-authors are Jeremy Bloxham and Sabine Stanley of Harvard University, whose computer model of the planets' interior strongly replicates the strange magnetic fields detected by Voyager 2.
Hard evidence to back it will only come from a probe to Uranus or Neptune, they admit.
No such mission is being planned for the moment, but scheduled treks by US and US-European probes to Saturn and Mercury should yield exciting new data to test the theory of how planetary magnetic fields are born, they say.
TOPICS: News/Current Events
KEYWORDS: astrology; astronomy; buzzingflies; capkirk; cappykirk; captainkirk; catastrophism; crevolist; enemaofuranus; enigmaofuranus; jupiter; lynardskynard; neptune; planets; rainbowflag; saturn; solarsystem; thereisgasinuranus; tp; uranus
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![This NASA Hubble Space Telescope Advanced Camera for Surveys image of Uranus reveals the planet's faint rings and several of its satellites.(AFP/NASA)](http://us.news2.yimg.com/us.yimg.com/p/afp/20040311/capt.sge.rve73.110304030921.photo00.default-243x419.jpg) This NASA (news - web sites) Hubble Space Telescope (news - web sites) Advanced Camera for Surveys image of Uranus reveals the planet's faint rings and several of its satellites.(AFP/NASA) |
To: NormsRevenge
He said uranus... hu-huh-hu-huh
2
posted on
03/10/2004 10:49:05 PM PST
by
Bismarck
To: KevinDavis; PatrickHenry; RadioAstronomer; Sabertooth
ping
3
posted on
03/10/2004 10:58:20 PM PST
by
farmfriend
( Isaiah 55:10,11)
To: NormsRevenge
Very interesting article. Good find. Thanks!
4
posted on
03/10/2004 10:59:55 PM PST
by
Prime Choice
(Hm? No, my powers can only be used for Good.)
To: NormsRevenge
Wow. Uranus is a lot bigger than I had originally imagined.
5
posted on
03/10/2004 11:00:46 PM PST
by
ambrose
("John Kerry has blood of American soldiers on his hands" - Lt. Col. Oliver North)
To: NormsRevenge; Physicist; RadioAstronomer; RightWhale
For me the enigma of Uranus is that it rotates at 90 degrees unlike the earth at 23 degrees and most other planets.
If you believe in the acreation mode of planet formation and conservation of angular momentum, the 90 degree tilt makes no sense.
6
posted on
03/10/2004 11:03:25 PM PST
by
staytrue
To: ambrose
It's time for me to call it a night. Very interesting article, but I'm betting on about a 70% smart-*ssed response, and at least three references to Captain Kirk and toilet paper. I'll check back in the morning.
BTW, I didn't know there were rings around Uranus.
To: NormsRevenge
Hmmm... too easy. Turns outs, Uranus is a black hole.
8
posted on
03/10/2004 11:05:10 PM PST
by
Chad Fairbanks
(I hope my posts didn't incontinence anyone...)
To: NormsRevenge
(Professor Farnsworth has just invented the Smelloscope.) Farnsworth: Youll find that every heavenly body has its own particular scent.
Fry: As long as you dont make me smell Uranus! Ha! Ha!
Farnsworth: Im sorry, Fry, but astronomers renamed Uranus in 2620 to end that stupid joke once and for all.
Fry: Oh. Whats it called now?
Farnsworth: Urectum.
9
posted on
03/10/2004 11:24:26 PM PST
by
ikka
To: NormsRevenge
Q: Why is toilet paper like Star Trek?
A: Because both search for Klingons circling Uranus.
10
posted on
03/10/2004 11:28:06 PM PST
by
mcg1969
To: Richard Kimball
You're welcome. :)
11
posted on
03/10/2004 11:28:53 PM PST
by
mcg1969
To: NormsRevenge
Hubble is Unbelievable!! Looks like a "flyby" photo!
12
posted on
03/10/2004 11:38:12 PM PST
by
Indie
(The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants.")
To: PatrickHenry
"Planet that shall remain nameless" ping...
13
posted on
03/10/2004 11:49:56 PM PST
by
Aracelis
To: NormsRevenge
14
posted on
03/11/2004 12:16:50 AM PST
by
Bullish
To: Bismarck
Isn't Uranus big and gassy?
15
posted on
03/11/2004 12:45:32 AM PST
by
Recovering_Democrat
(I'm so glad to no longer be associated with the Party of Dependence on Government!)
To: *crevo_list; VadeRetro; jennyp; Junior; longshadow; RadioAstronomer; Physicist; LogicWings; ...
Mandadory Uranus PING. [This ping list is for the evolution side of evolution threads, and sometimes for other science topics. FReepmail me to be added or dropped.]
16
posted on
03/11/2004 3:25:23 AM PST
by
PatrickHenry
(A compassionate evolutionist.)
To: staytrue
Unless it was hit by something REALLY BIG at one time...
17
posted on
03/11/2004 3:54:00 AM PST
by
Junior
(No animals were harmed in the making of this post)
To: NormsRevenge
Hard evidence to back it will only come from a probe to UranusFederal legislation to fund the probe was sponsored by Congressman Bawney Fag (D-MA).
18
posted on
03/11/2004 4:32:40 AM PST
by
reg45
To: NormsRevenge
ping
19
posted on
03/11/2004 4:42:38 AM PST
by
grb
To: PatrickHenry
Solved at last? I'd say Uranus remains a far-away mystery and I like it that way.
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