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View Full Version : 1,500 mph Winds On Neptune-Chase THAT!!



Saul Trabal
10-15-2005, 10:51 PM
Neptune has the most violent weather in the solar system. Winds there are clocked at 1,250 mph. While Neptune's Great Dark Spot was in existence, one of the Voyager probes found winds in the spot at 1,500 mph-the highest wind speed found on any planet in our solar system. That's twice the speed of sound.

Now, how would you folks like chasing THAT???

:P :twisted:

Andrew Khan
10-15-2005, 10:57 PM
How did they measure that high of wind speed? No intrument could survive that...was it something like DOW?

Karen Politte
10-15-2005, 11:37 PM
Chasing anything that doesn't occur on earth doesn't exactly fill me with enthusiasm......more boredom, actually.

KR

Anthony Silver
10-16-2005, 12:00 AM
Nah, Doesn't exactly appeal to me either. Winds of that magnitude would likely obliterate a human body.

Mike Hollingshead
10-16-2005, 12:04 AM
I'm game. Where is my ship?

Robert Dewey
10-16-2005, 12:15 AM
Sounds interesting to me... Beam me up, Scotty!

Saul Trabal
10-16-2005, 12:27 AM
Originally posted by Andrew Khan
How did they measure that high of wind speed? No intrument could survive that...was it something like DOW?

It was measured by one of the Voyager probes.

Saul Trabal
10-16-2005, 12:30 AM
Originally posted by Karen Rhoden
Chasing anything that doesn't occur on earth doesn't exactly fill me with enthusiasm......more boredom, actually.

KR

Er...huh?

If you don't find a 300 mph F5 twister boring, why would you find a wind twice the speed the sound boring? Just because you couldn't be right there to measure it??

That's some odd logic.

Pat Lawrence
10-16-2005, 02:53 AM
Great info, Saul!

I think most people that have an interest in weather also have an interest in astronomy. I have no stats on this, but I have little doubt that it be the case :D

This is a cool Hubble site:
http://hubblesite.org/gallery/album/entire_collection/

Pat

B Ozanne
10-16-2005, 08:06 AM
It seems like we go over this every year. Yes, Neptune may have 1500 mph winds but the extremely low density of air would make that 1500 mph wind feel like a mere puff. Yes, the air particles are travelling that fast, but there aren't that many of them.

If you are interested in doing a comparison use this Excel Spreadsheet generated by the Mount Washington Observatory: http://www.easternlight.net/Wind.xls

Just plug in pressure, wind speed, and temperature and you can compare the force for several sites.

Karen Politte
10-16-2005, 08:39 AM
Originally posted by Saul Trabal+--><div class='quotetop'>QUOTE(Saul Trabal)</div>
<!--QuoteBegin-Karen Rhoden
Chasing anything that doesn't occur on earth doesn't exactly fill me with enthusiasm......more boredom, actually.

KR

Er...huh?

If you don't find a 300 mph F5 twister boring, why would you find a wind twice the speed the sound boring? Just because you couldn't be right there to measure it??

That's some odd logic.[/b]

Err.....no. I find it boring because it doesn't occur on the planet that we humans inhabit. Ergo - I will never chase it. Ergo - so what? :roll:

Also - if you want to get technical - the "winds" on that planet apparently don't manifest themselves in the form of a tornado - merely winds. I am sure that if all earth's tornado wind-speeds occurred as straight-line gusts, there wouldn't be half the chasers out there! :wink: We're visual creatures.......

Just a bit of fun..... :P

KR

Angie Norris
10-16-2005, 08:56 AM
Just give me a rover, send me to Mars and I'll chase dustdevils and collect rocks :D .
Angie

Saul Trabal
10-16-2005, 09:17 AM
Originally posted by Karen Rhoden+--><div class='quotetop'>QUOTE(Karen Rhoden)</div>

Originally posted by Saul Trabal@
<!--QuoteBegin-Karen Rhoden
Chasing anything that doesn't occur on earth doesn't exactly fill me with enthusiasm......more boredom, actually.

KR

Er...huh?

If you don't find a 300 mph F5 twister boring, why would you find a wind twice the speed the sound boring? Just because you couldn't be right there to measure it??

That's some odd logic.

Err.....no. I find it boring because it doesn't occur on the planet that we humans inhabit. Ergo - I will never chase it. Ergo - so what? :roll:

Also - if you want to get technical - the "winds" on that planet apparently don't manifest themselves in the form of a tornado - merely winds. I am sure that if all earth's tornado wind-speeds occurred as straight-line gusts, there wouldn't be half the chasers out there! :wink: We're visual creatures.......

Just a bit of fun..... :P

KR[/b]

Well, then I'll have to agree to disagree with you in the strongest of terms. :P

I don't take anything away from Earth's storms-which are awesome and frightening in their own right. But I'm not going to dismiss another planet's meteorology because "I can't be there." :roll:

:D

Robert Dewey
10-16-2005, 09:40 AM
Originally posted by Saul Trabal
I don't take anything away from Earth's storms-which are awesome and frightening in their own right. But I'm not going to dismiss another planet's meteorology because \"I can't be there.\" :roll:

:D

I'd have to agree with you there - I find all sorts of meteorology fascinating, as well as astronomy. I am probably one who is in the small minority of liking high winds... For that reason, I like to chase severe thunderstorms - not JUST tornadoes. Also, chasing hurricanes is something that interests me greatly, and something I wish I could do. I always hate when people say they "busted" a chase because they didn't see a tornado - yet they may have witnessed some incredible other forms of meteorology.

Then I also agree with Karen... It really is a bit more exciting if you're there, experiencing it first hand.

Karen Politte
10-16-2005, 09:51 AM
I can understand where people are coming from when they get excited about thousand-mph wind gusts on some alien planet. But - for the sake of being pedantic and extrememly annoying.......does the term meteorology actually encompass the study of other alien planets' atmospheric conditions???

Perhaps someone needs to coin a phrase for other-wordly weather. And then post about it, on AstronomyTrack - the astral traveller's resource since space exploration began. :lol:

/annoying

KR

Saul Trabal
10-16-2005, 10:49 AM
Oddly enough, given what I've read on the subject of thunderstorms on other planets, it's too bad there isn't more discussion about it. One recent news item on Cassini said it discovered massive columns of thunderstorms in Saturn's atmosphere that had lightning 10,000 times more powerful than Earth's.

So, my POV is this:

Earth-based storms are incredible. They blow me away-pun intended. ;) I gaze in awe at them. They frighten me. I respect their power.

Now, take storms like that and make them the size of continents, or the size of planets like Earth. Make the lightning bolts so powerful that they could possibly destroy a small town or city. Make the thunder so loud that listening to it close-up could destroy your eardrums.

Imagine tornadoes coming from these storms that would make the worst F5 twister look like a mere summer breeze. Imagine these tornadoes being so huge that they could engulf whole cities, possibly states.

Now, try to imagine yourself looking at storms like this.

That where my excitement on severe alien weather comes from. And I believe we have those kinds of storms in our solar system.

:D

Saul Trabal
10-16-2005, 11:01 AM
This link (http://www.spacetoday.org/SolSys/Saturn/CassiniSaturnNews.html) has the news item on Saturn's thunderstorms.


I tell ya, if Cassini doesn't take CLOSE-UP pictures of the limb/cresent of Saturn from its night side, I'll be VERY, VERY dissapointed. I've seen pictures of Earth's limb taken from the night side, where you'd see thunderclouds mushroom into the sky. You could also see the surrounding cloud structures, as well as the blue sky and the sun shining through.

I must admit to being furious that this wasn't done with the Galileo spacecraft. Taking pictures of the storms from directly above is wonderful, but since we can't actually place a probe in the atmosphere of these gas giants to take pictures, this is the next best thing. Frankly, the more I think about it, the more furious I am. And I do remember some great shots of Jupiter's limb from the night side-but they weren't close-ups.

What a dissapointment. :(

Andrew Khan
10-16-2005, 11:05 AM
I'll tell you, I don't care where those winds are...there still wind! I find it very important to know there is winds like this elsewhere...to a greater extent, however. If I could, I would go chase storms over there, lol...and it's only a matter of time until we get those storms here.... :lol:

Angie Norris
10-16-2005, 11:13 AM
Amen, Saul!!!!!
Why do we humans have to be so arrogant that we have to compare everything that happens to what we only know about Earth and go into a non-acceptance mode if it doesn't compare to those expectations. Open up and be willing to expand to include the unknown and different.
There is some study being done in extra-terrestrial meteorology and we do have one prof here at OU who does just that (I know beause I asked my old astronomy prof). I just haven't worked up enough nerve to go talk to her (yes, I said her :D ) because I just don't really want to know how much more math would be involved in those classes :shock: :cry: .
I think it would be so awesome to investigate how weather behaves in the non-terrestrial setting.
Angie

Andrew Khan
10-16-2005, 11:19 AM
Unfortunatly, I think that is just human nature....sad, isn't it? I accept it...

Pat Lawrence
10-16-2005, 11:34 AM
For those wondering about the term meteorology being used regarding the weather patterns on other worlds:

http://www.giss.nasa.gov/research/planets/

Read the last sentence. The article is on a NASA website...an organization that also has no small amount to do with the weather satellite images taken of earth. I'm not about to argue with the terminology they choose to use lol

I'd be rather interested to learn what every person's definition of a meteor is, as well :D Without doing a net cheat!

Angie Norris
10-16-2005, 12:02 PM
I think the original Greek definition was the study of anything that falls out of the sky. Didn't specify what is falling or where the sky happens to be.... :wink:
Angie

Pat Lawrence
10-16-2005, 12:10 PM
Originally posted by Angie Norris
I think the original Greek definition was the study of anything that falls out of the sky. Didn't specify what is falling or where the sky happens to be.... :wink:
Angie

My small attempt at humor...which I see you picked up on quickly :D Are you absolutely certain I was referring to the sky? lol That would imply I'm being an earth-centrist in everything I ever say or type....heaven forbid!

In any event, I just thought I'd have a little fun with this.

Pat

Ps I virtually chased Neptune for my current avatar :) Of course the image is from NASA.

Mike Hollingshead
10-16-2005, 01:12 PM
Also - if you want to get technical - the \"winds\" on that planet apparently don't manifest themselves in the form of a tornado - merely winds. I am sure that if all earth's tornado wind-speeds occurred as straight-line gusts, there wouldn't be half the chasers out there! We're visual creatures.......

Keep counting me in! I'd chase it for the FEEL of it. I'd be a multi-sensory chaser I suppose. I LOVE strong winds. Before anyone gets anal on my a$$ I realize I can't breathe there. And not to mention the fact that because I'd like it doesn't mean I'm saying they'd have to.


Perhaps someone needs to coin a phrase for other-wordly weather. And then post about it, on AstronomyTrack - the astral traveller's resource since space exploration began.

/annoying

Well, I found it more interesting than "welcome cold front". That should be on weather.com forums, not a CHASER forum! What chaser is happy to see a fall cold front(I admit sometimes I like them, but just trying to make a point). Sorry, doing my part for annoyances.

nickgrillo
10-16-2005, 01:41 PM
Growing up in MI, I learned to love strong winds... And I chase for all aspects of severe weather (although tornadoes are a very special part of chasing).


Originally posted by Mike Hollingshead
Well, I found it more interesting than \"welcome cold front\". That should be on weather.com forums, not a CHASER forum! What chaser is happy to see a fall cold front(I admit sometimes I like them, but just trying to make a point). Sorry, doing my part for annoyances.

:lol: True, I suppose...

I wasn't really bothered by the thread at all, but I do see the point a few were trying to make. We need to keep this a storm chaser forum, people... Now get to making a thread about research on Derechos within a dry boundary layer immediately :wink:

Scott Olson
10-16-2005, 05:52 PM
How about a chase to Jupiter and the Big Red Spot?

-This storm has been going on for at least 300 years.
- It is TWICE the size of the Earth.
- Lightning in Jupiters storms is said to be 10,000 more powerful than that on Earth.
- Anti-cyclonic
- Winds of 300mph+
- Even smallest storms would trump our Supercells and probably contain
unimaginable vortexes.
http://img239.imageshack.us/img239/9540/redspotfalse24ix.jpg (http://imageshack.us)

Even Mars which doesn't have nearly as powerful or amazing atmosphere as Jupiter has dust devils which could put some Earth tornadoes to shame.

http://homepage.mac.com/karsten/Tech%20Ram...20050823012035/ (http://homepage.mac.com/karsten/Tech%20Ramblings/C105171974/E20050823012035/)

Andrew Khan
10-16-2005, 06:00 PM
They say a dust devil on Mars is like a moderate tornado here on earth, thats how much mpre pwerful they are there. I wonder what the tornadoes would be like on Jupiter....I also wonder if you would get any structure from this, lol....it's like a major hurricane/supercane. How do storm start there, on Jupiter/Mars? How can they start with such inferior oxygen/air?

Scott Olson
10-16-2005, 06:29 PM
Originally posted by Andrew Khan
They say a dust devil on Mars is like a moderate tornado here on earth, thats how much mpre pwerful they are there. I wonder what the tornadoes would be like on Jupiter....I also wonder if you would get any structure from this, lol....it's like a major hurricane/supercane. How do storm start there, on Jupiter/Mars? How can they start with such inferior oxygen/air?

Martian Dust Devils can reach several KM high and can range from 20 to 70mph (even greater perhaps). The reasoning for the storms is alot similar to that on our own planet that they consist of moist convection with atmospheric instability. Things that are different on Jupiter are:

1. Jupiters core supplies 70% of the energy.
2. Rain will evaporate prior to reaching the ground and the cycle repeats itself.

With a lot of the same dynamics involved (rising motion/instability/gaseous vapor+condensation/boundaries/pressure differentials) I don't see how there wouldn't be tornadoes associated with the thunderstorms on Jupiter.
Oxygen is not necessary Jupiters main cloud layer is frozen ammonia crystals (said to look like our Cirrus clouds). On Jupiter ammonia, phosphine, and water vapour, can condense.

It really dwarfs our atmosphere in size and makeup.

Andrew Khan
10-16-2005, 07:23 PM
Wow...such a sustained life-cycle, that's why I guess it's been going on for so many years on Jupiter. Hmm, the core supplies energy there, thats really interesting man. What is the gravitational force on Jupiter, compared to ours?

Thanks for the information Scott.

Saul Trabal
10-16-2005, 09:18 PM
Originally posted by Scott Olson
How about a chase to Jupiter and the Big Red Spot?

-This storm has been going on for at least 300 years.
- It is TWICE the size of the Earth.
- Lightning in Jupiters storms is said to be 10,000 more powerful than that on Earth.
- Anti-cyclonic
- Winds of 300mph+
- Even smallest storms would trump our Supercells and probably contain
unimaginable vortexes.


I wrote a story about that, on my site TRABAL CREATIONS. (http://users.erols.com/strabal/creations.html) :P :D

BTW-that info on Jupiter's lightning strength is inaccurate. I've seen that "factoid" in a couple of books. In fact, I saw lots of conflicting info in different areas on the strength of Jupiter's lightning. :roll:

It finally took an email to the folks behind the Galileo probe (which went to Jupiter) to get the right answer: Jupiter's lightning is 1,000 times more powerful than Earth's.

And I think 3 Earths could fit in the Great Red Spot. It's 25,000 miles long and 8,000 miles wide. :shock:

Scott Olson
10-16-2005, 09:27 PM
Originally posted by Saul Trabal+--><div class='quotetop'>QUOTE(Saul Trabal)</div>
<!--QuoteBegin-Scott Olson
How about a chase to Jupiter and the Big Red Spot?

-This storm has been going on for at least 300 years.
- It is TWICE the size of the Earth.
- Lightning in Jupiters storms is said to be 10,000 more powerful than that on Earth.
- Anti-cyclonic
- Winds of 300mph+
- Even smallest storms would trump our Supercells and probably contain
unimaginable vortexes.


I wrote a story about that, on my site TRABAL CREATIONS. (http://users.erols.com/strabal/creations.html) :P :D

BTW-that info on Jupiter's lightning strength is inaccurate. I've seen that "factoid" in a couple of books. In fact, I saw lots of conflicting info in different areas on the strength of Jupiter's lightning. :roll:

It finally took an email to the folks behind the Galileo probe (which went to Jupiter) to get the right answer: Jupiter's lightning is 1,000 times more powerful than Earth's.

And I think 3 Earths could fit in the Great Red Spot. It's 25,000 miles long and 8,000 miles wide. :shock:[/b]

I haven't seen the 1,000x stronger but I'll take your word for it. And the 2x for the earth is because the great red spot has shrunk over the years and is no longer as big as it was in the 70's. Thus, its a current estimation.

Andrew Geil
10-16-2005, 09:29 PM
1,000 times vs. 10,000 times more powerful.

I bet I can still cook my hamburger with it.

Or the entire cow.

Saul Trabal
10-16-2005, 09:31 PM
Originally posted by Andrew Khan
Wow...such a sustained life-cycle, that's why I guess it's been going on for so many years on Jupiter. Hmm, the core supplies energy there, thats really interesting man. What is the gravitational force on Jupiter, compared to ours?

Thanks for the information Scott.

You need to realize one other thing...

Jupiter is not a rocky world. It is a giant ball of liquid hydrogen. The atmosphere is a mere skin on this ball of liquid. Temperatures at the transition point from atmosphere to liquid hydrogen (there might not be a surface; the atmospheric pressure increases until it becomes liquid) might be thousands of degrees. When the Galileo probe was dropped into the Jovian atmosphere, the last recorded transmission was at 175 miles down-atmospheric pressure 22 bars, temperature, 300 degrees Fahrenheit. Jupiter emits more heat than it recieves from the sun.

So, it's little wonder that Jupiter's weather is so ferocious. The same can be said about Saturn. Uranus and Neptune might have a mixture of water, ammonia, methane and liquid hydrogen as part of their interiors. For some reason, though, Neptune has the most violent weather in the solar system..

BTW Pat-love the avatar. :D Neptune's Great Dark Spot was the size of Earth. It dissipated, however. :? That doesn't mean we won't see more storms like that. :)

(edited for spelling)

Saul Trabal
10-16-2005, 09:37 PM
Originally posted by Andrew Geil
1,000 times vs. 10,000 times more powerful.

I bet I can still cook my hamburger with it.

Or the entire cow.

Cassini detected lightning discharges from Saturn that were ONE MILLION times more powerful than Earth's lightning. :shock: :shock: :shock: :shock:

You could cook every cow on the frigging planet-among a few other things.

:P

Saul Trabal
10-16-2005, 09:48 PM
More on Saturn's Monstrous Lightning (http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=1355)

cdcollura
10-17-2005, 11:20 AM
Good day,

I am quite interested in such "meteorology" on other planets too. The gas giant planets (Jupiter, Saturn, Uranus, and Neptune) all have very dynamic and interesting atmospheres.

The storm on Neptune was measured in velocity by estimating the size of the storm, and its apparent cloud motion of clouds within, sort of like video grammetry in tornadoes to estimate wind speed. This is also done with satellite estimates of wind speeds using cloud motions (Dvorak method) with hurricanes right here on earth!

With Neptune, the atmosphere at the level of that storm was estimated at over 700 MPH. You see that little white cloud over the storm? That is called the "Scooter" cloud and was estimated to move at the 1,250 to 1,500 MPH we all heard about.

Another point is air (or gas) density. There is what we call INDICATED and TRUE airspeed. A 100 MPH wind on the earth's surface at sea level is 100 MPH, as we feel it blow against us. At 500 MB, that same 100 MPH wind will only produce the equivalent of a 75-MPH wind at sea level. At about 34,000 feet (250 MB) it would be live a 50-MPH sea-level wind, even though the air molecules are still moving at 100-MPH.

A jet plane at 34,000 feet "experiences" about 250-MPH of wind force against it, this is the INDICATED air speed, and shows at 250-MPH on the airspeed indicator based on pressure (dynamic pressure on a little pipe called a "pitot" tube). But the TRUE airspeed at 34,000 feet is actually double that, or about 500-MPH. The Concorde, flying at about 65,000 feet, has a TRUE airspeed of about 1,300 MPH but only "feels" 350 MPH on its instruments because the air is so thin up there.

A person in the atmosphere of a planet like Jupiter or Neptune first of all will be moving with the winds, since there is nothing to remain "still" on, like a mountain or something - But let's say there was. First of all, a hydrogen (or methane) atmpshere is much less dense than air here on earth, and is most likely rarefied, like 100 MB or so, at such a height as the "top" of the Great Red Spot, or "Scooter" cloud on Neptune. Again, we have a TRUE airspeed of 1,500 MPH, but stick your hand out into it, and it may "push it back" with the force of (only) a 200-MPH wind on earth near sea level (the 200 being the INDICATED speed).

Now, since the density is much less, it also weighs a lot less too per parcel of atmosphere. Less force is required to set the parcel in motion, so it is quite possible that something that may cause a 200-MPH jet stream on earth, can produce a 2,000 MPH wind in a lighter, less dense medium!

The gas giant planets also do not get their "weather driving" energy from the sun, like here on earth. They are heated from within, as the compression of their gaseous (then liquid) cores are driven by their immense gravity. In Jupiter, compression is so extreme that the hydrogen is compressed into a superheated METAL like state called "metallic hydrogen" which even has a strong magnetic field. Convection drives storms from such a hot interior, in much the same way a hurricane on earth intensifies more at night because the heat from the underlying ocean.

Planets, like Jupiter, are also fast rotating. Jupiter completes a full rotation is only 10 hours or so, despite it being 1,000 times the volume of earth. Try to imagine the CORIOLIS force of Juputer!

Traces of water vapor were found in Jupiter's atmosphere by the Galileo mission, one of which was a thunderstorm cloud 50 miles (250,000 feet) high and about 700 miles wide! Galileo also released an atmosphere probe into the planets clouds, which descended to a region of about 22,000 mb (22 earth atmospheres at sea level, or 323 PSI). That is where the probe failed ... But it measured (via inertial guidance / drift indicators) wind speeds (400 MPH) at that level of twice what it encountered at the top layers of the clouds (200 MPH), dispelling the theory of lighter and less dense gas moving easily.

Remember INDICATED vs TRUE? Well the OPPOSITE applies for higher pressures and densities. A 100-MPH TRUE wind in 20 atmospheres will excert an INDICATED force equivalent to a 2,000 MPH wind at sea level - Ouch! No one was ever able to explain why the winds INCREASED with depth on Jupiter, unlike on earth where the winds are usually stronger aloft (example - Jet Stream).

One speculation was that the weather is even more violent UNDER the clouds due to the gravity heating theory, and also since there is no surface to create a boundary layer (friction) like on earth.

These planets are all that intriguing, especially with their extreme, beautiful, and unique meteorology ... Maybe someday some brave individuls will be lucky enough to experience it in-situ and first hand!

Chris C - KG4PJN

Mike Kay
10-17-2005, 04:51 PM
This link (http://www.spacetoday.org/SolSys/Saturn/CassiniSaturnNews.html) has the news item on Saturn's thunderstorms.


I tell ya, if Cassini doesn't take CLOSE-UP pictures of the limb/cresent of Saturn from its night side, I'll be VERY, VERY dissapointed. I've seen pictures of Earth's limb taken from the night side, where you'd see thunderclouds mushroom into the sky. You could also see the surrounding cloud structures, as well as the blue sky and the sun shining through.

I must admit to being furious that this wasn't done with the Galileo spacecraft. Taking pictures of the storms from directly above is wonderful, but since we can't actually place a probe in the atmosphere of these gas giants to take pictures, this is the next best thing. Frankly, the more I think about it, the more furious I am. And I do remember some great shots of Jupiter's limb from the night side-but they weren't close-ups.

What a dissapointment. :(

There may be a reason why the those probes didn't get any closer to Jupiter and Saturn - radiation belts. Jupiter is known to have far more larger - and dangerous radiation belts than Earth does. These are regions in the inner magnetic field that trap charged particles coming from the sun and concentrate into very high concentrations. Earth has such belts, and they're known as Van Allen Belts.

Jupiter's radiation belt is dangerous enough to kill a human in less than 24 hours. The radiation also nearly fried the electronic systems on the Pioneer 10/11 probes in the late 1970s for good and also degraded the Galileo orbiter probe's ability to study and take pictures of Jupiter and its moons over time. I don't know how powerful Saturn's magnetic field and radiation belts are compared to Jupiter's, but it would still be a lot bigger and more powerful than Earth's. So, I'd imagine the JPL people won't be dumb enough to try to bring a $1 billion probe at such a close orbit to Saturn lest its onboard computer systems gets fried by the radiation. Not only that, there might also be a risk of severe damage from particles in Saturn's rings, too.

Saul Trabal
10-17-2005, 05:50 PM
This link (http://www.spacetoday.org/SolSys/Saturn/CassiniSaturnNews.html) has the news item on Saturn's thunderstorms.


I tell ya, if Cassini doesn't take CLOSE-UP pictures of the limb/cresent of Saturn from its night side, I'll be VERY, VERY dissapointed. I've seen pictures of Earth's limb taken from the night side, where you'd see thunderclouds mushroom into the sky. You could also see the surrounding cloud structures, as well as the blue sky and the sun shining through.

I must admit to being furious that this wasn't done with the Galileo spacecraft. Taking pictures of the storms from directly above is wonderful, but since we can't actually place a probe in the atmosphere of these gas giants to take pictures, this is the next best thing. Frankly, the more I think about it, the more furious I am. And I do remember some great shots of Jupiter's limb from the night side-but they weren't close-ups.

What a dissapointment. :(

There may be a reason why the those probes didn't get any closer to Jupiter and Saturn - radiation belts. Jupiter is known to have far more larger - and dangerous radiation belts than Earth does. These are regions in the inner magnetic field that trap charged particles coming from the sun and concentrate into very high concentrations. Earth has such belts, and they're known as Van Allen Belts.

Jupiter's radiation belt is dangerous enough to kill a human in less than 24 hours. The radiation also nearly fried the electronic systems on the Pioneer 10/11 probes in the late 1970s for good and also degraded the Galileo orbiter probe's ability to study and take pictures of Jupiter and its moons over time. I don't know how powerful Saturn's magnetic field and radiation belts are compared to Jupiter's, but it would still be a lot bigger and more powerful than Earth's. So, I'd imagine the JPL people won't be dumb enough to try to bring a $1 billion probe at such a close orbit to Saturn lest its onboard computer systems gets fried by the radiation. Not only that, there might also be a risk of severe damage from particles in Saturn's rings, too.

I'm not 100% sure I buy that. The reason is that the Galileo probe got close enough to take pictures of individual thunderstorm clouds on Jupiter, as well as various lightning discharges on the night side.

While I agree about the radiation danger, I'm rather dubious about that being the reason close-up or zoom pics of the limb weren't taken.

I spoke to Anthony Del Genio via email about this idea-one of the folks involved with Cassini-and he said perhaps they might try what I suggested, assuming they can fit it into the schedule.

Saul Trabal
10-17-2005, 05:56 PM
^
^

BTW Mike-

Go here (http://dosxx.colorado.edu/JUPITER/ATMOSPHERES/73.html) to check out some pics of storms on Jupiter, and take a look at this pic (http://dosxx.colorado.edu/JUPITER/ATMOSPHERES/ThunderStorms/GALILEO/PIA01639.jpg) of a Jovian thunderhead. This storm is about 600 miles in diameter, I think.

So-if Galileo could get photos of a thunderstorm like this up close, I can't see why they couldn't get zoomed-in photos of the planet's limb that would show the sky color and clouds in a more 3-d manner.

Saul Trabal
10-17-2005, 06:00 PM
cdcollura,

Fascinating post! Thanks! :D

Pat Lawrence
10-17-2005, 08:23 PM
Sounds like fun, but you know gas prices this year are pretty high. :lol:

No doubt! I drive a economy car and it makes me sick each time it costs over 20 to fill it up.

It might just be me, but it doesn't seem like it is getting that 35 or so miles a gallon it used to :) Sorry I drifted off topic...

Pat

Mike Kay
10-17-2005, 10:58 PM
^
^

BTW Mike-

Go here (http://dosxx.colorado.edu/JUPITER/ATMOSPHERES/73.html) to check out some pics of storms on Jupiter, and take a look at this pic (http://dosxx.colorado.edu/JUPITER/ATMOSPHERES/ThunderStorms/GALILEO/PIA01639.jpg) of a Jovian thunderhead. This storm is about 600 miles in diameter, I think.

So-if Galileo could get photos of a thunderstorm like this up close, I can't see why they couldn't get zoomed-in photos of the planet's limb that would show the sky color and clouds in a more 3-d manner.

Thanks, Saul

I've seen those thunderstorm pics quite some time ago, actually. A lot of what cdcollura just posted, I've also been aware of that for quite a while, too.

These thunderstorms seem to be made of water vapour and water ice, just like Earth's storms. And they seem to be a major source for those super-powerful lightning bolts on Jupiter.

But what I've read in the past was that Jupiter was found to have probably a lot less water than expected, especially in light of the Galileo atmospheric probe observations. The global lightning flash rate on Jupiter seems to be a lot less frequent than Earth's, even though Jupiter's lightning bolts are much more powerful.

Like cdcollura, I've found the weather on gas giants to be interesting.

Saturn may not be that much different, except that it does have higher wind speeds than Jupiter. Have you seen the Dragon Storm on Saturn? This is one interesting storm becasuse it looks pretty odd. Check this out here (http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=3763).

Given the high rotation rates and high amount of interior heat of many gas giants, I'm sure supercells must occur very frequently on planets like Jupiter and Saturn.

With the recent discovery of so many extrasolar planets in recent years, most of them gas giants, it may be interesting to think what may go on in extrasolar planets.

Extrasolar gas giants lying within the habitable zone (zone where Earthlike conditions are possible) of its parent sun may have clouds made largely of water just like Earth, instead of ammonia or hydrogen of gas giants farther out. But the atmosphere is likely to be unbreathable methane or ammonia or whatnot. Such a planet may have a white or silvery appearance.

Now, this is where the fun begins, as I said before that water is a better lightning generator than ammonia for example! Imagine truly enormous supercells even bigger than Jupiter's and mega-funnels. And the lightning.....! That kind of gas giant may not only have bolts rivaling or even exceeding Jupiter's in intensity, but they'll also be much more frequent. Imagine a gas giant flecked with lightning like it has fireflies all over it!

That'd be quite a show for any inhabitants of an Earth-like moon or space colony orbiting the water-rich gas giant!

Saul Trabal
10-18-2005, 12:22 AM
Mike,

Yes, I know all about the Dragon Storm. :D In fact, I've been in email discussions with Anthony Del Genio about it. It's a super-thunderstorm more than half the size of the earth. It's also a long-lived feature. The white spot in the center is the anvil of the actual storm, and the long feathery lines are probably cirrus blow-off. I'm not sure what they're made of-possible a water/ammonia mix.

Here's an email conversation we had a while back about the Dragon Storm. My comments are in italics.


Apparently, from what I've read at the link above, the Dragon Storm is
a long-lived feature.

Yes, as far as we can tell, at depth it may be long-lived. We don't see it all the time in our images, but it flares up now and then in about the same location, so whatever is causing it deep down lasts for a long time. Unlike storms on Earth, which can't maintain themselves for very long times against dissipation by radiation and surface friction, storms on the jovian planets, once formed, can hang around for a while because there's no solid surface and the cold atmosphere radiates very slowly.

Perhaps Cassini could be focused on trying to
take pics of its vertical structure from the limb?

Nice idea, but our observations for the entire nominal mission through 2008 had to be planned and sequences designed and sent to JPL a year or two ago, because the mission is too complex and there just aren't enough people working on it at JPL to put in changes on the fly. That grates on me, but those are the fiscal and manpower realities. However, I myself designed at least a few days of observing sequences focused on the 30-45 deg. S latitude band for later this year, so we'll hope it's there during that time. And next year when we're on the night side we'll hopefully get a few cracks at what you suggest.

This storm looks to be one massive weather system. Judging from its
size, I would surmise that it's almost half the size of the earth, if
not bigger.

That's about right, I'd say. However, if you look at the attached flase-color image, it's really only the bright white-yellow oval in the middle that we'd guess is the actual thunderstorm. The rest of the wavy filamentary stuff is probably just the high-level cirrus or cirrostratus blowoff, or anvil cloud, that forms where the convective updraft detrains, or spits out, its condensed water and water vapor into the surrounding environment. Then, givent he strong winds on Saturn, those get stretched out for quite a distance. Nonetheless, I think that the convective core for this storm is easily 1000 km.

I've often wondered about such storms putting out

super-tornadoes that would be far more devastating than anything we
would encounter on earth.

On Earth, that happens when a storm erupts in a region of strong vertical wind shear, and the horizontal vortex tubes get tilted into the vertical by the updrafts. On Saturn, we don;t yet know whether there's enough wind shear below the visible cloud deck for that to happen, although we have some hints that there is significant shear down there. If you look at Figure 5 of our attached Science paper, you can see the dragon storm apparently giving "birth" to two dark spots at the end of the sequence. We don't know if those are vortices, but they may well be. There are lots of rotating things like that on the jovian planets, much bigger than terrestrial tornadoes, but I can;t rule out similar processes happening. If not, then their generation may have more in common with nor'easters, where a synoptic-scale vortex tube stretches vertically and tightens its radius of curvature (though the instability process may not be the same).

I would also imagine that hailstones must be
incredibly massive, given how big this storm seems to be. How big
could hailstones get in such a storm?

I'm not sure whether we get hail in these storms. To get that you need supercooled liquid water being lofted up repeatedly well above the freezing level into the ice-forming region of the storm. We don't know where the bases of the storms are on Saturn, but it's possible they form above the freezing level, in which case they'd be mostly ice and make a lot of snow that turns to rain deeper down, but not much hail. But if the water abundance is large enough on Saturn, then they could form at warmer temperatures and hail would be possible. But I wouldn't necessarily guess the hail would be bigger than on Earth. On Earth you get the biggest hail when the most instability is built up and suddenly you get enough moisture at low levels to kick off the storm, making strong updrafts. That's common in the midwest, which is a farily unique place on Earth meteorologically due to the mountains upstream and the Gulf of Mexico to the south as a moisture source. In contrast, convection is much deeper and more ubiquitous in the tropical west Pacific, but it's weak and makes little hail because instability never has a chance to build up enough to make strong updrafts - there's usually enough humidity near the ocean surface to make a storm from the least bit of instability. Saturn may be more like that than the midwest.

Regards,
Tony Del Genio

8)

cdcollura
10-18-2005, 11:13 AM
Good day,

In addition to the intriguing gas giant planets and their meteorology, a recently (about 5-10 years ago) discovered extra-solar body called a BROWN DWARF exists. This is a extremely large gas giant type planet, many times as massive as Jupiter, but still to small to compress, heat, and initiate nuclear fusion in its core. These are also much cooler, and are about 3,000 degrees instead of like the sun's 10,000 degrees at their surfaces.

With this said, astonomers looking at these noticed "flickering" of their brightness, mostly in the dull-red visible and the infrared spectrum. A conclusion was made that this was caused by changing cloud patterns, where a temporary clearing would cause more "light" from the underlying, hotter layers of the "atmosphere" of the brown dwarf to shine through.

Spectral analysis showed hints of iron vapor in these clouds of the brown dwarf. Like anything, including water, heat energy and latent heat is released when a gas condenses to a liquid. Iron vapor, even at 3,000 degrees, will also "release" energy when it rises and condenses, although the laten heat energy may be different than that of water.

This can drive huge convective storms on such atmospheres of brown dwarfs. A detailed article on this can be read below...

http://spaceflightnow.com/news/n0207/23dwarfwx/

Very interesting,

Chris C - KG4PJN