Discovery of Saturn’s auroral heartbeat
An international team of scientists led by Dr Jonathan Nichols of the University of Leicester has discovered that Saturn’s aurora, an ethereal ultraviolet glow which illuminates Saturn’s upper atmosphere near the poles, pulses roughly once per Saturnian day.
The length of a Saturnian day has been under much discussion since it was discovered that the traditional ‘clock’ used to measure the rotation period of Saturn, a gas giant planet with no solid surface for reference, apparently does not keep good time.
Saturn, like all magnetised planets, emits radio waves into space from the polar regions. These radio emissions pulse with a period near to 11 h, and the timing of the pulses was originally, during the Voyager era, thought to represent the rotation of the planet. However, over the years the period of the pulsing of the radio emissions has varied, and since the rotation of a planet cannot be easily sped up or slowed down, the hunt for the source of the varying radio period has become one of the most perplexing puzzles in planetary science.
Now, in a paper to be published in Geophysical Research Letters (August 6), Nichols et al. use images from the NASA/ESA Hubble Space Telescope of Saturn’s auroras obtained between 2005-2009 to show that, not only do the radio emissions pulse, but the auroras beat in tandem with the radio.
Dr Nichols said: “This is an important discovery for two reasons. First, it provides a long-suspected but hitherto missing link between the radio and auroral emissions, and second, it adds a critical tool in diagnosing the cause of Saturn’s irregular heartbeat.”
Auroras, more commonly known as the “northern lights” on Earth, are caused when charged particles in space are funnelled along a planet’s magnetic field into the planet’s upper atmosphere near the poles, whereupon they impact the atmospheric particles and cause them to glow. This happens when a planet’s magnetic field is stressed by, for example, the buffeting from the stream of particles emitted by the Sun, or when moons such as Enceladus or Io expel material into the near-planet space.
Saturn’s radio waves were long suspected to be emitted by the charged particles as they hurtle toward the poles, but no radio-like pulsing had been observed in Saturn’s aurora, an enigmatic disconnect between the two supposedly-related phenomena.
However, Nichols et al. found that by using the clock of the radio pulsing to organise the auroral data, and stacking the results from all the Hubble Saturn auroral images obtained from 2005-2009 on top of each other, the auroral pulsing finally revealed itself.
Dr Nichols added: “This confirms that the auroras and the radio emissions are indeed physically associated, as suspected. This link is important, since it implies that the pulsing of the radio emissions is being imparted by the processes driving Saturn’s aurora, which in turn can be studied by the NASA/ESA spacecraft Cassini, presently in orbit around Saturn. It thus takes us a significant step toward solving the mystery of the variable radio period.”
Galactus says:
August 4, 2010 at 11:18 pm
But Los Alamos National Laboratory states…
It does not. Some guy who used to work there claims…
J.Hansford says:
August 4, 2010 at 11:28 pm
” because geomagnetic activity depends on Universal Time”…… Intriguing. Could you elucidate further Leif?
In Northern Hemisphere summer the Earth’s axis is tilter towards the Sun and the magnetic pole rotates around the axis such as to be ‘into the solar wind’ at 16:30 UT. This diminishes geomagnetic activity because the solar wind sees a stronger geomagnetic field. The same is the case for the Southern Hemisphere during its summer, except at 4:30 UT. The last page of http://www.leif.org/research/geoact.htm has more.
E.M.Smith says:
August 5, 2010 at 1:38 am
Well NASA says we have “Flux Transfer Events” that connect the Earth to the Sun periodically… So we have a “magnetic universe”?
Indeed we do.
So I don’t know what to call it when you have charged particles flowing inside a conduit from one place to another, but it happens from the Sun to the Earth.
A stream of charged particles is not an electrical current. To be that, the charges will have to be of the same sign, and the solar plasma is electrically neutral, i.e. has the same number of positive and negative charges. When those charges encounters the strong magnetic field of the Earth, they are separated: positive charges are diverted into one direction and negative charges into the opposite direction. In this way local electric currents are created, which can now enter the atmosphere as Birkeland currents.
Louis Hissink says:
August 5, 2010 at 3:43 am
Moving electrically charged particles is “Electricity”
No, see my response upthread. To be electricity the charges will have to be of the same sign.
vukcevic says:
August 5, 2010 at 5:44 am
On numerous occasions I have said in my posts that interaction between solar magnetic ‘rope’ (cloud) and planetary magnetospheres depends on planets heliocentric longitude (nose or tail of heliosphere).
That you say it multiple times does not make it so. There is no evidence [or reason] for any of this.
ok, my question, borne of ingnorance, is this:
“Saturn, a gas giant planet with no solid surface for reference”
The Earth has an iron core to create a magnetic field, or so is my understanding. How does a gas giant with no solid surface accomplish this?
Steve M. from TN says:
August 5, 2010 at 7:45 am
The Earth has an iron core to create a magnetic field, or so is my understanding. How does a gas giant with no solid surface accomplish this?
That the [liquid] core is iron is not important. Any conducting liquid or gas will do. E.g. the Sun has a magnetic field too.
Now, in a paper to be published in Geophysical Research Letters (August 6), Nichols et al. use images from the NASA/ESA Hubble Space Telescope of Saturn’s auroras obtained between 2005-2009 to show that, not only do the radio emissions pulse, but the auroras beat in tandem with the radio.
So perhaps Saturn is our cosmic subwoofer? (boom-pa-boom-pa-boom)
Leif Svalgaard says:
August 5, 2010 at 6:55 am
“[…]A stream of charged particles is not an electrical current. To be that, the charges will have to be of the same sign, and the solar plasma is electrically neutral, i.e. has the same number of positive and negative charges.[…]”
Leif, do the positive and negative charges in the solar plasma move synchronously, or do their speeds differ from each other?
Leif Svalgaard says: August 5, 2010 at 6:55 am
There is no evidence [or reason] for any of this.
You may think so. But there is a good reason and evidence, it is the asymmetry of heliosphere, its anisotropy increases with the distance from the sun (10 AU).
Hey, know it all doc, ESA scientists differ, here is direct quote:
Based on the new observations, scientists now think there are two possible reasons for the change in radio period.
The first theory is that the geysers on Enceladus could be more active now than in Voyagers’ time. The second is that there may be seasonal variations as Saturn orbits the sun once every 29 years.
http://www.esa.int/esaCP/SEM1KTS4LZE_index_0.html
It appears your views are frozen in some long gone decade, together with your one legged ‘magnetic universe’.
Universe is not ‘magnetic’ not ‘electric’ but both electro-magnetic and electromagnetic.
Where can we get that radio-transmitter that works withour electrical power, just with a fridge’s magnet?
Saturn, like all magnetised planets, emits radio waves into space from the polar regions.
DirkH says:
August 5, 2010 at 8:36 am
Leif, do the positive and negative charges in the solar plasma move synchronously, or do their speeds differ from each other?
They move together. Now, there are a very small flux of high-energy particles that move independently, but they make no significant contribution to the overall neutrality of the plasma. Look at it this way: the [mass] bulk of the solar wind is positive protons. The matching electrons can’t move far away from the protons because the electrical attraction between the two opposite charges is so enormous.
For the FLINTSTONES’ UNIVERSE believers ions are not electrically charged, they are just little pebbles painted in different colors. Wow!
vukcevic says:
August 5, 2010 at 9:08 am
The second is that there may be seasonal variations as Saturn orbits the sun once every 29 years.
Seasonal variations, like summer and winter. On the Earth there are also such seasons. Nothing to do with the heliosphere. Here you can learn more about the seasons: http://en.wikipedia.org/wiki/Season
Enneagram says:
August 5, 2010 at 9:18 am
Where can we get that radio-transmitter that works withour electrical power, just with a fridge’s magnet?
Put the fridge’s magnet inside a loop of copper wire, then twirl the magnet and connect your transmitter to the wire, and it will emit.
vukcevic says:
August 5, 2010 at 9:08 am
I just can’t believe my eyes!….now everything is possible, let’s make a “séance” to talk to spirits!
Louis Hissink says:
August 5, 2010 at 3:43 am
Folks,
Moving electrically charged particles is “Electricity”
yup. plasma cosmology is so much more convincing than the sorry state of “modern” physics.
JP says:
August 5, 2010 at 4:51 am
Perhaps it is time to realize that the problem of “climate science” is in fact part of a much bigger problem in physics.
bingo
From the American Geophysics Union (AGU):
If this is a more acceptable source for the moderators, it is an area of study for the AGU as well.
peterhodges says:
August 5, 2010 at 10:03 am
yup. plasma cosmology is so much more convincing than the sorry state of “modern” physics.
yup, just like it is much more convincing that the Earth is flat and that the whole universe rotates about the Earth once a day and that maggots are created spontaneously from nothing in rotten meat.
Thanks Leif, I guess if I’d thought about it, I would have realized that 🙂
Zeke the Sneak says:
August 4, 2010 at 11:05 pm
Vlad the Impaler says:
August 4, 2010 at 10:43 pm
The Music of the Spheres. Do you hear them? They make such beautiful music.
So….what a surprise!, didn’t know Vlad the impaler had a sensible hear.
As for the rest: Let’s get to the basic!: Do, Re, Mi, Fa, So, La, Si, Do……entiende?
Zeke the Sneak says:
August 5, 2010 at 10:24 am
AGU: “It should play a central role in attracting plasma physicists, space scientists, middle-atmosphere experts as well as traditional atmospheric electricity researchers”
If this is a more acceptable source for the moderators, it is an area of study for the AGU as well.
Everything of interest is generated by electricity, on the Sun, in space, in the upper atmosphere. The important point is that that electricity is generated by moving conducting [but neutral] plasma across magnetic fields or induced in the conducting [but neutral] plasma by rapidly changing magnetic fields.
Steve M. from TN says:
August 5, 2010 at 10:37 am
Thanks Leif, I guess if I’d thought about it, I would have realized that 🙂
Many people here might also benefit from a bit of thought.
So Saturn now becomes the QUASAR of the neighborhood!
So Kronos had a sensible heart too….I wonder if he is talking to us: “Hear me those who have ears to hear…”
He had an strange predilection for eating all his deaf sons…
Doc have you ever heard of an electrolyte battery or a solar electric cell, or they do not exist in ‘one-legged magnetic universe’.
Vuk etc says:
August 5, 2010 at 11:08 am
“straddle universe”….
Vuk etc says:
August 5, 2010 at 11:08 am
Doc have you ever heard of an electrolyte battery or a solar electric cell, or they do not exist in ‘one-legged magnetic universe’.
Both of these devices owe their workings to the fact that there are insulators involved. In a cosmic plasma there are no large-scale insulators.
There one-leggedness comes from the fact that it is meaningless to talk about an electric field without specifying a reference frame. One observer will measure one field in his frame, a different observer will observe a different electric field if moving relative to the first. You can always find an observer that sees no electric field in his frame. E.g. in the solar wind the electric field in the frame moving with the plasma is zero.
However, the magnetic field does not depend on the frame of references. All observers will measure [almost] the same magnetic field. Hnece the one-legged magnetic universe.
Leif Svalgaard says:
August 5, 2010 at 10:32 am
peterhodges says:
August 5, 2010 at 10:03 am
yup. plasma cosmology is so much more convincing than the sorry state of “modern” physics.
yup, just like it is much more convincing that the Earth is flat and that the whole universe rotates about the Earth once a day
sorry leif. i guess the physics of plasma have no effect on anything. the sun is not plasma. the suns atmosphere is not plasma. planetary atmospheres have no plasma effects. there is no plasma in space, and therefore no electricity in space.
Leif Svalgaard says:
August 5, 2010 at 10:44 am
Everything of interest is generated by electricity, on the Sun, in space, in the upper atmosphere. The important point is that that electricity is generated by moving conducting [but neutral] plasma across magnetic fields or induced in the conducting [but neutral] plasma by rapidly changing magnetic fields.
which is it?
and by “modern” physics, i mean BB/standard cosmology… it is prima facie preposterous. it is an obvious train wreck, and more a product of politics than even AGW/climatology.
leif, it is not the skeptic who continuously piles on contradictory ad-hoc epicycles to save the theory from reality, and it is not the skeptic who refuses all progress by ridiculing people who are only pointing out the obvious.
you ought to be ridiculing the bb/standard cosmology faithful – it is they who are the flat-earth-centric deniers of progress in our time. BB/standard cosmology is not empirical science, it is religion posing as science.
let me just say, it seems naive to deny that the physics of plasma has no role in the structure of the physical reality we experience, when said plasma is ubiquitous.
read this page , which i hope is noncontroversial. and everywhere substitute “plasma” for “gas” just to get an idea of how ubiquitous is plasma.
just as every climatology paper requires a nod to AGW and CO2 to get published, everything written about cosmology must have “gas” instead of “plasma” and a mention of relativity to get published.