by neufer » Wed Apr 06, 2016 3:05 pm
heehaw wrote:
Saturn does have a magnetic field, and, remarkably, it is precisely aligned with Saturn's spin (rotation) axis, the only celestial object for which such alignment occurs! Wonder why?
Gas giant Saturn & ice giant Neptune
are quite similar in that they both:
- 1) Radiate ~255% their Solar energy
2) Have extremely high surface winds.
However, gas giant Saturn & ice giant Neptune differ radically in their dipole tilts:
- 1) Saturn dipole tilt <0.5°
2) Neptune dipole tilt ~47°
Is this dipole tilt difference because the strong internal heating source is mostly
- 1) Above the thin shell of electrically conducting liquids for Saturn but
2) Below the thin shell of electrically conducting liquids for Neptune
https://en.wikipedia.org/wiki/Magnetosphere_of_Saturn wrote:
<<Like Jupiter's magnetic field, Saturn's is created by a fluid dynamo within a layer of circulating liquid metallic hydrogen in its outer core. Saturn's magnetic dipole is strictly aligned with its rotational axis, meaning that the field, uniquely, is highly axisymmetric (i.e., dipole tilt <0.5°).
Saturn has a hot interior, reaching 11,700 °C at its core, and it radiates 2.5 times more energy into space than it receives from the Sun. Jupiter's thermal energy is generated by the Kelvin–Helmholtz mechanism of slow gravitational compression, but this alone may not be sufficient to explain heat production for Saturn, because it is less massive. An alternative or additional mechanism may be generation of heat through the "raining out" of droplets of helium deep in Saturn's interior. As the droplets descend through the lower-density hydrogen, the process releases heat by friction and leaves Saturn's outer layers depleted of helium. These descending droplets may have accumulated into a helium shell surrounding the core.>>
https://en.wikipedia.org/wiki/Neptune wrote:
<<Neptune also resembles Uranus in its magnetosphere, with a magnetic field strongly tilted relative to its rotational axis at 47° and offset at least 0.55 radii, or about 13500 km from the planet's physical centre. Before Voyager 2's arrival at Neptune, it was hypothesised that Uranus's tilted magnetosphere was the result of its sideways rotation. In comparing the magnetic fields of the two planets, scientists now think the extreme orientation may be characteristic of flows in the planets' interiors. This field may be generated by convective fluid motions in a thin spherical shell of electrically conducting liquids (probably a combination of ammonia, methane and water) resulting in a dynamo action.
Neptune's more varied weather when compared to Uranus is due in part to its higher internal heating. As with Uranus, the source of this heating is unknown, but the discrepancy is larger: Uranus only radiates 1.1 times as much energy as it receives from the Sun; whereas Neptune radiates about 2.61 times as much energy as it receives from the Sun. Neptune is the farthest planet from the Sun, yet its internal energy is sufficient to drive the fastest planetary winds seen in the Solar System. Depending on the thermal properties of its interior, the heat left over from Neptune's formation may be sufficient to explain its current heat flow, though it is more difficult to simultaneously explain Uranus's lack of internal heat while preserving the apparent similarity between the two planets.>>
[float=right][img3="[b][color=#0000FF]Tilts of planetary magnetic fields with respect to their rotation axes.
Credit: Fran Bagenal & Steve Bartlett[/color][/b]"]http://lasp.colorado.edu/home/mop/files/2012/04/4Tilts.jpg[/img3][/float][quote="heehaw"]
Saturn does have a magnetic field, and, remarkably, it is precisely aligned with Saturn's spin (rotation) axis, the only celestial object for which such alignment occurs! Wonder why?[/quote]
Gas giant Saturn & ice giant Neptune
are quite similar in that they both:
[list]1) Radiate ~255% their Solar energy
2) Have extremely high surface winds.[/list]
However, gas giant Saturn & ice giant Neptune differ radically in their dipole tilts:
[list]1) [b][color=#FF0000]Saturn dipole tilt <0.5°[/color][/b]
2) [b][color=#0000FF]Neptune dipole tilt ~47°[/color][/b][/list]
Is this dipole tilt difference because the strong internal heating source is mostly
[list]1) [b][color=#FF0000]Above[/color][/b] the thin shell of electrically conducting liquids for Saturn but
2) [b][color=#0000FF]Below[/color][/b] the thin shell of electrically conducting liquids for Neptune :?: [/list]
[quote=" https://en.wikipedia.org/wiki/Magnetosphere_of_Saturn"]
<<Like Jupiter's magnetic field, Saturn's is created by a fluid dynamo within a layer of circulating liquid metallic hydrogen in its outer core. Saturn's magnetic dipole is strictly aligned with its rotational axis, meaning that the field, uniquely, is highly axisymmetric (i.e., dipole tilt <0.5°).
Saturn has a hot interior, reaching 11,700 °C at its core, and it radiates 2.5 times more energy into space than it receives from the Sun. Jupiter's thermal energy is generated by the Kelvin–Helmholtz mechanism of slow gravitational compression, but this alone may not be sufficient to explain heat production for Saturn, because it is less massive. An alternative or additional mechanism may be generation of heat through the "raining out" of droplets of helium deep in Saturn's interior. As the droplets descend through the lower-density hydrogen, the process releases heat by friction and leaves Saturn's outer layers depleted of helium. These descending droplets may have accumulated into a helium shell surrounding the core.>>[/quote][quote=" https://en.wikipedia.org/wiki/Neptune"]
<<Neptune also resembles Uranus in its magnetosphere, with a magnetic field strongly tilted relative to its rotational axis at 47° and offset at least 0.55 radii, or about 13500 km from the planet's physical centre. Before Voyager 2's arrival at Neptune, it was hypothesised that Uranus's tilted magnetosphere was the result of its sideways rotation. In comparing the magnetic fields of the two planets, scientists now think the extreme orientation may be characteristic of flows in the planets' interiors. This field may be generated by convective fluid motions in a thin spherical shell of electrically conducting liquids (probably a combination of ammonia, methane and water) resulting in a dynamo action.
Neptune's more varied weather when compared to Uranus is due in part to its higher internal heating. As with Uranus, the source of this heating is unknown, but the discrepancy is larger: Uranus only radiates 1.1 times as much energy as it receives from the Sun; whereas Neptune radiates about 2.61 times as much energy as it receives from the Sun. Neptune is the farthest planet from the Sun, yet its internal energy is sufficient to drive the fastest planetary winds seen in the Solar System. Depending on the thermal properties of its interior, the heat left over from Neptune's formation may be sufficient to explain its current heat flow, though it is more difficult to simultaneously explain Uranus's lack of internal heat while preserving the apparent similarity between the two planets.>>[/quote]