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.”
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Wow, this is amazingly cool! 🙂 And timely too, with the recent solar storm of August 1st.
In other words, Birkeland currents are feeding solar electricity into planetary polar regions, thus making them marbles spin. Fascinating stuff. What do you think Leif?
[REPLY: Any “electric universe”… I won’t even call it pseudoscience…. trolling beyond this point will be embargoed. – Mike]
Birkeland currents seem to be quite accepted and real. Whence the connection with the “electric universe” folks would seem to be quite tenuous at best.
Wow you mean the sun actually does things, I thought Saturn’s CO2 would be doing this?
“Auroras, more commonly known as the “northern lights” on Earth”
Except, of course, for the aurora australis, or southern lights. 😉
Yet another important step in the direction of Plasma Cosmology, a concept already known and well understood by many. Mainstream is of course lagging behind, but that’s the speed of consensus in any field, but they’ll hopefully catch up later.
Honest question… why is everyone soft stepping around half of the term electro-magnetic?
Yes, there are some wackos out there, but than everyone said that about Mr E, for a while…
Anti-magneto says:
August 4, 2010 at 7:42 pm
In other words, Birkeland currents are feeding solar electricity into planetary polar regions
Max Hugoson says:
August 4, 2010 at 8:03 pm
Birkeland currents seem to be quite accepted and real.
Birkeland currents are real and important, but are not solar electricity. Instead they are generated locally at the planet by changing magnetic fields. And I agree with the moderator that it serves no purpose here to debate the ‘electric universe’.
Apart from this, the Earth’s aurorae also have a ‘heartbeat’ related to rotation, because geomagnetic activity depends on Universal Time. The mechanism is, however, different from that at Saturn.
Jack “In Oregon” Barnes says:
August 4, 2010 at 9:34 pm
Honest question… why is everyone soft stepping around half of the term electro-magnetic?
Because there are no electric fields in the rest frame of a highly-conducting plasma, but there are magnetic fields, so the one half is duly missing, but let’s not get started on this [again].
“Saturn, like all magnetised planets, emits radio waves into space from the polar regions.”
–as do Saturn’s rings, recorded by NASA some years ago (along with the moons Miranda and Io, and other gas giants. But the “Voice of the Earth” is most beautiful.).
“Cassini’s Radio and Plasma Wave Science (RPWS) instrument takes high-resolution measurements that allow scientists to convert the radio waves into audio recordings by shifting the frequencies down into the audio frequency range.”
Saturn’s Rings
What an impressive picture!
Love a good scientific mystery! Makes your mind spin.
(Hope it doesn’t make some science minds out there spin off into nana land).
Keeping this on pure physics, it first brings to mind some anisotropy in the magnetic field of Saturn but with no such map at hand that’s just a first probability. How else could the pulse be so close to daily? For a symmetric field should show no daily differences therefore no pulse nature. Surely Cassini was to map the magnetic field, hope so.
Next it seems to imply that for some reason Saturn’s magnetic field may not be firmly bound to the rotation but move with its non-solid nature, once again ,just a most obvious observation. Do flows of the gases and liquids on the near surface affect or even control Saturn’s magnetic field itself which makes the daily timing float? In that manner weather or currents on the surface or near surface could modify the magnetic field throwing off the timing. Seems feasible.
Intriguing questions.
The Music of the Spheres. Do you hear them? They make such beautiful music.
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.
“all the arts lose virtue”
R. Jeffers
Ah, real data from real scientific hardware…. I get annoyed when I think of all the money that was wasted on the pseudoscience of climate modeling along with the politicization of the AGW hypothesis….. A lot more scientific hardware could have been built with that money…. Real things that measure and observe.
Ah well. It’s never too late. Onward and forward.
Claim: “Birkeland currents are real and important, but are not solar electricity. Instead they are generated locally at the planet by changing magnetic fields.”
But Los Alamos National Laboratory states, quote: “The plasma universe consists of swirling streams of electrons and ions flowing in filaments. Where pairs of these spaghettilike structures interact, the particle gain kinetic energy and at narrow ‘pinch’ regions produce the entire range of galaxy types as well as the full spectrum of cosmic electromagnetic radiation. Thus galaxies must lie ‘like pearl beads on a necklace’ along filaments, much as they are observed to do on a large scale. The bulk of the filaments are invisible from a distance, much like the Birkeland currents that circle the Earth but are invisible from its surface. In space, these currents are called Birkeland Currents, in honor of the 19th century physicist who suggested their existence. In the laboratory, they are called Bennett-pinches, Z-pinches, or ‘Zed’ pinches. In 1934 W. H. Bennett discovered that streams of electrons flowing in the axial or Z-direction, self pinch from the magnetic field they generate around themselves.”
http://public.lanl.gov/alp/plasma/elec_currents.html
So, according to Los Alamos National Laboratory, one of the most respected scientific laboratories in the world (if not the most credible), Birkeland currents are not just a local phenomenon generated by planetary magnetic interaction with the solar wind. Electric Birkeland Currents – flowing in space – could also pinch and form galaxies due to self-generated magnetic fields. And how about star formation and planets? It certainly looks like there’s more to these electric currents than first thought.
Very interesting indeed.
Leif Svalgaard says:
August 4, 2010 at 9:36 pm
……………. “Apart from this, the Earth’s aurorae also have a ‘heartbeat’ related to rotation, because geomagnetic activity depends on Universal Time. The mechanism is, however, different from that at Saturn.”
________________________________________________________
” because geomagnetic activity depends on Universal Time”…… Intriguing. Could you elucidate further Leif?
It is ironic indeed that the promoters of one brand of pseudoscience get distressed when another brand creeps into their discussions.
It is hard enough to challenge scientific consensus in one field, i.e. climate and CO2 which WUWT does magnificently, attempting another challenge, EU or PU is likely to bring more derision from another mainstream orthodoxy, which will dilute the results achieved here.
Sites such as Thunderbolts .info or Plasma Universe have sites devoted entirely to these fields and IMHO discussions would be more fruitful in the long run if they are discussed there.
Well NASA says we have “Flux Transfer Events” that connect the Earth to the Sun periodically… So we have a “magnetic universe”?
http://science.nasa.gov/science-news/science-at-nasa/2008/30oct_ftes/
Somehow I don’t feel any better from calling the electromagnetic force by one half of it’s name over the other…
But in either case, there is “stuff” flowing in space from the Sun to the Earth and it does “stuff” when it gets here:
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.
And NASA said so, so it must be right 😉
Moderator Mike
You mention “electric Universe ” trolls – sounds a bit closed minded to me. Surely you should be applying the old Scottish approach – “not proven”? Or maybe plasma physics is outside your area of specialism?
Folks,
Moving electrically charged particles is “Electricity”
http://geoplasma.spaces.live.com/blog/cns!C00F2616F39D0B2B!1180.entry
I’ll wait until the paper is published so I can look at the data before I offer ideas about the cause of the ‘heartbeat’.
Julian Braggins says:
August 5, 2010 at 1:32 am
The two orthodoxies are in fact intimately intertwined, through the name James Hansen. Velikovsky was the first to predict in the 1950s that Venus was a very hot planet and had a retrograde rotation (under the hypothesis that Venus was a young planet), and everyone laughed at him, with official estimates at the time that the temperature of Venus was similar to that of Earth. Once probes sent to Venus showed that in fact Velikovsky was right, it was a certain James Hansen who saved orthodoxy, with the idea of a runaway greenhouse effect on Venus with his 1967 PhD at Iowa State University.
Hansen has never given up on the idea of the runaway greenhouse effect, and has contributed enormously to the idea of the runaway greenhouse effect on Earth, i.e., global warming, now renamed to climate change.
Perhaps it is time to realize that the problem of “climate science” is in fact part of a much bigger problem in physics.
For some of us who interested in the planetary magnetic fields and general Electro-Magnetic interactions within solar system, this is a bit of old hat.
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).
More about this puzzle here:
http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_23-3-2007-11-2-7
IC’s graphic is not there but you can see it here: http://www.vukcevic.talktalk.net/SatMf.htm
There are two solutions proposed:
– Saturn geysers are more active than in the 1970s, throwing out more mass into the atmosphere.
– variations along the Saturn’s 29+ year orbit depending on its heliocentric position.
Of course I would favour the second, but no resolution may come for another 20+ years, when the planet will retrace its path.
Correction.
It should be : Enceladus geysers are more active than in the 1970s, throwing out more mass into the atmosphere.
Enceladus graphic: http://www.vukcevic.talktalk.net/SatMf.htm