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http://antwrp.gsfc.nasa.gov/apod/ap9706 … ]Reference to Marsian aurora phenomena here
*That's a reposted article, by the way (originally commented on with respect to Jupiter in the "Dark Rings of Jupiter" thread). I couldn't help noticing Mars mentioned in the caption, which brought back to mind a brief conversation here at New Mars a long time ago (I tried to find the discussion again, with no success): At that time I asked if it were possible Mars has aurora phenomena despite claims its magnetic field is "patchy." Someone said they doubted it. Yesterday I did a bit of research on Google and I found an article from the late 1990s which claimed all of Mars is engulfed in a magnetic field; weak, but complete. ??? One source says it's a patchwork, another says it's a complete field. :-\
Unfortunately I lost that link but am sure I can relocate it again today.
Any comments, either about aurora phenomena on Mars or the magnetic field issue?
--Cindy
We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...
--John Sladek (The New Apocrypha)
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Hmmm.
I was under the impression the magnetic field was a 'fossil remnant' of an earlier global field - but very patchy. Some areas, if I remember correctly, have as much as 1/3rd of terrestrial field levels, while other places effectively have none.
But I'd be happy to be found wrong on that!
As for aurorae on Mars, I don't remember seeing any definite reference to that, apart from the link you've given us here.
The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down. - Rita Rudner
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http://www.spacedaily.com/mars/features … html]Found it!
*Whew...I almost couldn't relocate it on Google.
This is "news" to me.
I was under the impression the magnetic field was a 'fossil remnant' of an earlier global field - but very patchy. Some areas, if I remember correctly, have as much as 1/3rd of terrestrial field levels, while other places effectively have none.
*Yep.
--Cindy
We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...
--John Sladek (The New Apocrypha)
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I see from the articles dating that there might be the question of, if the core is cooling has the magnetic field also lessened with time? Or is this more of the permanent magnetic material style field that was measured.
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off topic, but related(?)... This triggers a memory...
In the 80's I read an article that in the Mars atmosphere certain alignments with the sun generates an amount of coherent light at (one of the) the poles, don't ask me how, and now, years later, it sounds very odd to me, but it was in a 'serious' science mag...
Some scientists-dreamers even talked about setting up two large mirrors circling above the pole, one semi-permeable, thus creating a *huge* laser-tube...
It would function as a big beacon for other intelligent species... kind of saying: "we're here, talk to us!" Since it would be quite easy to figure out that the begin point of that huge laser show means intelligent life playing with stuff...
(Mastery of English down the drain... Didn't get enough sleep, but I guess you get the gist.)
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Thanks, Cindy, for the heroic effort in finding the article for us. :up:
If I've ever seen reference to a global magnetic field around Mars of 1/800th the strength of Earth's, it has completely slipped my mind. (Not too difficult a feat, by the way! )
According to Dr. J. Marvin Herndon, it's possible that planets might have natural nuclear reactors at their cores, pumping out heat in a rhythmic pattern over time. This interests me in relation to Mars because it would explain how such a small world can have relatively recent evidence of extensive volcanism on its surface billions of years after its primordial internal heat, together with heat released by the fission of unstable radionuclides, should have died away.
If such planetary nuclear reactor cores exist, Dr. Herndon has determined that they would shut down for longish periods, as fission by-products accumulate. These contaminants, being lighter, eventually rise out of the core, allowing the reactor to go critical once more and churn out vast quantities of energy.
He also suggested that such shut-downs and restarts would neatly explain Earth's waxing and waning magnetic field and the polarity reversals which often occur when the field approaches zero.
With this in mind, I've wondered whether it's possible we've arrived at Mars, by chance, at a time when its reactor core is in shut-down mode or, at least, close to its low point in the cycle.
If Mars' magnetic field is at such a low point, registering 1/800th of Earth's, it's not surprising that the dominant observable magnetic effects would come from fossil crustal fields. I suspect if you took away Earth's strong global field, you would notice the fossil fields more too.
Anyway, the point of all this hypothesising is that the tiny global field detected around Mars may be the beginning of the next strong phase of planetary magnetism, or the fading remnant of the last one.
I haven't come up with a reasonable explanation for the lack of any significant fossil crustal fields in Mars' northern plains and in the Hellas Basin yet, though. Unless they're so buried in fluvial sediment that the weak fields in those regions are so far undetectable(?).
???
[The idea of Mars as a sporadically much more volcanically active place than it's commonly assumed to be is dear to my heart. I'm glad it's been brought up again. ]
Hi Rik.
That article about a natural laser effect at one of the martian poles sounds very interesting too. I'd like to read it some day.
The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down. - Rita Rudner
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