After much speculation, it has finally been confirmed-lightning occurs on Venus. Here's the link:

http://www.cbsnews.com/stories/2007/...n3549985.shtml

Pretty cool!

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"Yes...! To you, Baldrick, the Renaissance...was just something that happened to other people, wasn't it??"

This has been a frustrating controversy for a long time, with seemingly as much evidence for as against (and increasingly, against). Assuming it's confirmed at last, this is great, exciting news!

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"Call me old-fashioned, but I think fire is magic. And it scares me a lot."

--The State

I'm a bit puzzled about why lightning flashes haven't been seen in the clouds. Is it because Venus's atmosphere is so much thicker than Earth's?

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"Yes...! To you, Baldrick, the Renaissance...was just something that happened to other people, wasn't it??"

(By the way, this was also reported in an article in topic Venus Express - the ESA mission to Venus, in Space Exploration.)

It's been suspected for a long while, but Venus Express apparently had the magnetometer to clinch it.

Suspicion: ESA: Acid clouds and lightning

Confirmation: NASA Scientist Confirms Light Show on Venus

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From the ESA article:Two reasons. One, the sheer mass of the atmosphere. Even upper-atmosphere winds have to fight a lot of friction. Two, because such long exposure of the thick atmosphere to heat has evenly distributed energy over both hemispheres. No big temperature differential, no high winds.

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Is the lightning bright enough to contribute to the Ashen light question?

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

It is supposedly cloud-to-cloud lightning and according to the accompanying article in Nature, the atmosphere and clouds are so dense that standing on the surface you will not see the lightning. Depending on where the lightning is taking place, the same might be argued for being outside of the atmosphere.

According to a web document by Chris Russell (the lead author of the lightning paper) and J.L. Phillips the ashen light has many of the same characteristics as would be expected for lightning.

I am not sure whether any groups are looking at this phenomenon with VEX.

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Optimism does not change the laws of physics. (T'Pol)
A good scientist has freed himself of concepts and keeps his mind open to what is. (Dao De Jing 27)
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Martin ( http://www.geocities.com/DrMartinV )

Thanks. Your linked paper is excellent on the story of Ashen Light. The evidence for and against lightning as a cause has added to the enchantment. It seems lightning may occur intermittently.

George

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

Of course, the next question would be-are we talking about thunderclouds of sulphuric acid? If so, what are the differences between a Venusian thunderhead as opposed to a terrestrial thunderhead?

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"Yes...! To you, Baldrick, the Renaissance...was just something that happened to other people, wasn't it??"

The more often I read Russell's paper, the more doubt I have about his evidence (I am sad to say), but I am checking out things.

I don't think, that if there is any lightning going on, which is supposedly cloud-to-cloud, there will be a lot of difference. Naturally, the different composition of the atmosphere will create different discharge strengths, and a different composition of the clouds will most likely give a different "capacitance". So, they might either be stronger or weaker (well, isn't that a nice conclusion).

__________________
************************************************** *************************
Optimism does not change the laws of physics. (T'Pol)
A good scientist has freed himself of concepts and keeps his mind open to what is. (Dao De Jing 27)
************************************************** *************************
Martin ( http://www.geocities.com/DrMartinV )

Intermittently...?

From NASA News 79-12 (4-19-1979) p 1.:

"The Russian Venera spacecraft found continuous lightning activity from
32km down to about 2km altitude, with discharges as frequent as an amazing
25 per second. The Pioneer Orbiter also observed this lightning, measuring
such discharges during every pass across the planet's night hemisphere. The
eye would not be able to separate such frequent flashes and an observer on
Venus might see the landscape and dense atmosphere bathed in a continuous
eerie electrical glow, accompanied by continuous peals of thunder."

25 per second isn't exactly "intermittent." It's like, non-stop (to the point that a human eye would hardly be able to tell where one stopped and the next started)...

Granted, perhaps not "all the time at 25/second." But, yeah, a little more than "intermittent." Venus has a bit of a light show going on in its atmosphere. Granted it's buried where it's not "visible," per se...

~Michael Gmirkin

Yes, but don't discount Cassini's two flybys where AM static was found passing Earth but none when passing Venus.

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

Lightning does occur on venus, however, it never strikes the ground, air density (lack of atmosphere) prohibits it from grounding and confines itself to the gaseous clouds

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Thank God for magnetism.

Lack of atmosphere?
Don't you mean too much atmosphere?

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OK, I'm puzzled by all this.

1. The given explanation for the night-side glow of Venus is that solar radiation breaks down the CO2 & high speed winds transport the atoms around the planet to the night side where they recombine into O2, giving off the 'glow.' It is stated that the atmosphere of Venus is rotating significantly faster than the surface. This would seem to preclude the idea of no high-speed winds.

2. Venus Express has confirmed the presence of lightning on Venus using a magnetometer. As I can't find anywhere that mentions 'unusual' magnetometer readings, does that mean the VE is confirming Earth-type lightning?

3. If Earth-type lightning is occurring, particularly if it's occurring at rates like 25 times per second, why wouldn't Cassini have picked up the AM signature?

4. Wouldn't an atmosphere containing sulphuric compounds be more conductive than Earths? Could this affect the production of lightning & if so how?

Any en-lightning would be appreciated.

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* Never doubt there is Truth; just doubt that you have it!

Cassini hasn't picked up much in the way of lightning/static at Titan, either.

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jwj

It's ok not to know. We should try harder to find out.

OK... But why is that germane? From what I've read, it is only theory that Titan would have lightning isn't it? So the non-detection would just be evidence of an incorrect theory.

The Venus situation seems much more unsettled with evidence that there IS lightning contradicting the Cassini lack of detection. Is Cassini faulty somehow?

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* Never doubt there is Truth; just doubt that you have it!

Next week is the EGU general assembly. In the VEX session there will be more information about the lightning at Venus, by Russell.

I, myself, have looked at one event by Russell, and have found that there is the usual frequency change in the whistler mode waves, that are associated with lightning. However, as the frequency of the whistler waves is above the Nyqvist frequency of the magnetometer (being 62 Hz) the waves are "folded around" in the spectra, moving them from 100 Hz to 40 Hz and changing the direction of dispersion.

So, wait till after next week, then I can give more info on what Russell has done.

__________________
************************************************** *************************
Optimism does not change the laws of physics. (T'Pol)
A good scientist has freed himself of concepts and keeps his mind open to what is. (Dao De Jing 27)
************************************************** *************************
Martin ( http://www.geocities.com/DrMartinV )

Google is my friend Normally. But after reading about slow waves, packets, planes & propagation I guess I just have to settle for something like 'the evidence for lightning on Venus lies outside the expected result to be seen by the Cassini magnetometer.'

So is it a strange thing that Cassini saw results for Earth but not Venus?

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* Never doubt there is Truth; just doubt that you have it!