Hi.

This is my first post here, and I happen to be very curious about extra-terrestrial meteorology.

I have a fascination with violent weather. I'm awed by the fact that Jupiter's thunderstorms can reach 2,500 miles in diameter and contain lightning 1,000 times stronger than Earth's. It's too bad the Galileo probe wasn't able to fall into an area that was relatively near some storms.

I also wonder about Saturn, which will be visited by the Cassini probe in June (?) of this year. If Saturn's winds have been measured at over 1,000 miles an hour, would it follow that Saturn is hotter from within than Jupiter? if so, wouldn't thunderstorms there be even more violent than on Jupiter?

Finally-and this is the most fascinating question-how big would tornadoes get on each planet? Tornadoes HAVE to be a given with such violent storms.

The Great Red Spot, if I understand correctly, is a giant hurricane-with 300 mile-an-hour winds. I'm not sure that would qualify as a twister-but then, what do I know?

Any thoughts appreciated.

Out of question, but does anyone know if the Galileo atmosphere probe have a camera?

Nope-there was no camera on the Galileo probe. There **will** be one on Hyugens, the probe that will be dropped into the atmosphere of Saturn's moon, Titan.

Oh. Mars has interesting dust devilshttp://www.lpl.arizona.edu/~lemmon/impMPF/ .
Extra-terrestial weather IS intersting.

I'm aware of Martian dust devils. Winds on Mars can exceed 300 mph, which is why the dust storms are so huge.

BTW...

There was a GREAT show on the Discovery Channel called Planet Storm, which dealt with extra-terrestrial meteorology. I'd LOVE to get that on DVD.

I loved that show. But didn't it have something about a poleshift?

I don't think the conditions on the gas giants are right for tornadoes to occur. You'd probably need more terrestrial conditions (such as a surface and much different temperatures). But then again there may be a type of storm we've never even seen before, that is hidden below the top cloud layers of the gas giants. THAT is something that would be cool to find out.

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Man, just imagine. Jupiter and Saturn don't have surfaces, so storms would be completely three dimensional. They're not pancakes like here on Earth, they could be storm spheres, storm cylinders...

Heck, when the pressure gets high enough to force the gas into a liquid, it may not be a defined transition, and you would get storm winds that become storm currents, which could resonate through the entire inner core of the planet.

The things we could learn if only it were possible to go that deep...

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But he that sows lies in the end shall not lack of a harvest, and soon he may rest from toil indeed while others reap and sow in his stead. -J.R.R. Tolkien, The Silmarillion

I'm not sure I agree with this. You talk about differences in air temperature; well, near the top of Jupiter's atmosphere, the air temps are around -166 degrees Fahrenheit. Just before the Galileo probe ceased transmitting at around 175 miles into Jupiter's atmosphere, the air pressure was 22 earth atmospheres, and the temperature was 300 degrees Fahrenheit.

Not to mention, there is ample evidence of eddies in the Jovian atmosphere; just look at all the rotating storms. On Earth, tornadoes usually form when two air masses with drastic differences in temperature and humidity collide-and usually, the cold air mass is moving so fast that instead of wedging under the warm air, it goes over it a few miles, creating a tremendous imbalance. The overflowing cold air acts as a cap. Add to this a jet stream that can slice into this cap, and you have the birth of a tornado. The cap is taken off at different points along the cold front, causing the warm air to spiral upward.

On Jupiter, I am certain that similar circumstances occur-and I just find it hard to believe that thunderstorms of the severity found on Jupiter would not spawn tornadoes.

Still, no one has taken a shot at my other question:

My guess is that Saturn emits more heat than Jupiter, since its winds reach 1,000 miles per hour. If so, is it reasonable to assume that thunderstorms (and tornadoes) on Saturn would be that much more vicious?

Discuss.

I'm not sure I agree with the lack of a surface. I've felt that both Jupiter and Saturn have vast "oceans" of liquid hydrogen. Whether there is a gradual change from atmosphere to liquid is not certain. But the pressures at the surface of such an ocean must be around 90,000 Earth atmospheres.

Well, guess I should say they have no well defined surfaces.
The shear pressure says there must be a liquid layer and a solid core in there somewhere.

I'm rather fond of Arthur C. Clarke's idea that the center of Jupiter is actually a giant diamond formed from storm lightnings forming carbon compounds settling to the core, where the intense pressure and heat form a massive diamond core.

Probably pure fantasy, but still a neat idea.

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But he that sows lies in the end shall not lack of a harvest, and soon he may rest from toil indeed while others reap and sow in his stead. -J.R.R. Tolkien, The Silmarillion

The Discovery channel, or was it TLC, reran a program a couple weeks ago about Jupiter's atmoshphere. Some interesting special effects with examples given showing what to expect with flying thru Jovian air. Course, they show the plane being stuck by the deadly lightning, buffeted by 500 mph crosswinds, and careening down and down, eventually disappearing into the abyss.

Another juxtapose example of Jovan weather showed a typical Jupiter storm of hundreds and hundreds mph slamming into a large earthly city.
What's the point of it all you say? Guess they were trying to put Jupiter's weather in more of a human scale. Quite effective, too.

The program took the viewer into a science lab where they were trying to crack open the reason why and how Jupiter's clouds can remain separate, llike strata, even though they are in constant motion.

They had set up a very interesting experiment involving a spinning tub of water, about 60 rpm. A overhead camera peered down into the water, spinning at the same direction and rate. They'd drop different food color dyes in the spinning water.

With changing water temps, they achieved an identical look of swirling Jupiter storms. Even the giant red spot seemed to be replicated in the lab.

Said with the spinning tub of water, one would think the water would all spin in a great mass, all together in the same direction. What was shown was the spin caused a complex water motion of eddy currents, smaller storms (dye). Some would "eat" other storms. Some would arise and disappear.

As I recall, the secret was sutble temp changes and the rotation.

It would be more likely electrical currents from the liquid metallic hydrogen layer-which if I remember correctly, creates a magentic field 20,000 times stronger than Earth.

About Arthur C. Clark and "2010", that scene where astronauts are floating above Io is bogus. :P At that point, Jupiter's radiation belt is 1,000 times stronger than what's needed to kill a human. Then the Russian and American astronauts get aboard the Discovery and take their masks off?? LOL!!

What I'd like to see in my lifetime is a probe dropped into the Jovian atmosphere that would take pictures as it floated down. I can only imagine what a grand view the atmosphere would be like-especially if there were some massive thunderheads in the distance.

Oh well. Maybe that's asking too much.

That was "Planet Storm." =D>

I've GOT to get a DVD of that show... :P

About Jovian lightning...

I had read conflicting data in different books which had the lightning being anywhere from 10 times to 10,000 times more powerful than Earth's. I finally emailed the NASA/Galileo folks-and they told me that it was 1,000 times stronger than Earth's.

Scary, huh? And the thunderclaps could concievably destroy your eardrums.

Hailstones in Jovian thunderclouds...they must be IMMENSE.

I'd guess the size of grapefruit or higher. Thoughts?

We know how thunder sounds and reacts in our atmosphere.
Here's a question to ponder - how would thunder sound in Jupiter's unique atmosphere?

APOD picture of lightning on Jupiter:

http://antwrp.gsfc.nasa.gov/apod/ap971216.html

Another APOD image:

http://antwrp.gsfc.nasa.gov/apod/ap970512.html

(Imagine lightning bolts 500 kilometers across!)

Grapefruits? You can get that big on Earth. Jovian hailstones though? More like they'd be the size of Volvos or small buildings.

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But he that sows lies in the end shall not lack of a harvest, and soon he may rest from toil indeed while others reap and sow in his stead. -J.R.R. Tolkien, The Silmarillion

Grapefruit-sized hail does occur on Earth-but it is EXTREMELY rare. A thunderstorm which would put out that size hail would most likely be a tornadic supercell thunderstorm. Storms such as these reach heights of 60,000 feet on Earth and have updrafts nearing 200 miles an hour.

Small building-sized hail in a Jovian thunderstorm? Interesting...but even I wonder if hail gets to be THAT big there. Still, you have a hurricane big enough to swallow 3 Earths on Jupiter, so who knows.

Outside of the equatorial belt, another area that seems to be very active insofar as thunderstorm activity seems to be the poles of Jupiter. Photos of the north (?) pole of Jupiter seem to indicate LOTS of convection there. Maybe a probe outfitted with a camera should be sent there.

I've seen these pics quite a few times before. They are awesome.

In fact, this why I am so excited about the Cassini mission. I think thunderstorms may be more violent on Saturn than Jupiter.

The only diference I think would be how loud the lightning would sound. Regardless of the atmospheric composition (hydrogen, helium, methane, ammonia, water). At the 1 bar level, I'd imagine thunder would sound similar to Earth's, except MUCH, MUCH louder.

At higher air pressures? Now THAT'S the question. Hmmmm....

Old article on Jovian thunderstorms:

http://www.usatoday.com/weather/solar/wjupstorm.htm

Water cloud thunderstorm northwest of Great Red Spot:

http://photojournal.jpl.nasa.gov/catalog/PIA01639

8)

Well, logically, you should get a thunderclap that travels less distance but is much louder within that distance. More molecules to vibrate, so more energy can be transmitted to your ears, but more molecules to vibrate means the energy is spent faster.

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But he that sows lies in the end shall not lack of a harvest, and soon he may rest from toil indeed while others reap and sow in his stead. -J.R.R. Tolkien, The Silmarillion

I'm STILL waiting for an opinion on the following....

My guess is that Saturn emits more heat than Jupiter, since its winds reach 1,000 miles per hour. If so, is it reasonable to assume that thunderstorms (and tornadoes) on Saturn would be that much more vicious?

So? Anyone gonna tackle this??

:P :P :P :P

Oh, BTW...

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Pancakes??? ROFLMAO!!!

Well, jeeze-of COURSE they'd look like pancakes from space! But then, so does the Great Red Spot!!

I REALLY don't think that a tornadic supercell thunderstorm would qualify as a "pancake."

(snicker)