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Posted by: Dominik Sep 8 2005, 07:56 AM

Hello there.

I've got a question about the science data of the galileo probe mission (Plunge into jupiters atmosphere).

Is it possible to download the complete dataset of the mission? If yes, where can I find those data? I've tried to find them with google, but I found nothing.

Thx for help...

(Sorry for my bad english. I don't use it so often, because I'm from germany )

Posted by: DDAVIS Sep 8 2005, 11:20 AM

[quote=Dominik,Sep 8 2005, 07:56 AM]
Hello there.

I've got a question about the science data of the galileo probe mission (Plunge into jupiters atmosphere).

Is it possible to download the complete dataset of the mission? If yes, where can I find those data? I've tried to find them with google, but I found nothing.

Such a data set would be just what I need, for I would like to create an updated animation of the probe enviornment in scaled time showing probe motions, atmospheric opacity changes, and light levels. I made a detailed digital model of the probe for a Sky and telescope illo, which I would use in such a project. I animated the probe entry and descent in a traditional animation (film and painted cels) for Ames, which I still see in various space shows.

Don Davis

Posted by: djellison Sep 8 2005, 11:29 AM

I was actually thinking, when looking at a chart that John Zarnecki had of the tilt angle of the huygens probe on the way down to titan that it's a shame we've not seen the same treatment that we saw for the MER EDl sequence, applied to previous Entry sequences.

I dare say it could technically be done manually in an animation package - but it would be a nightmare.

If the Galileo stuff is anywhere -it'll be here
http://atmos.nmsu.edu/PDS/data/gp_0001/

Doug

Posted by: ljk4-1 Sep 8 2005, 12:58 PM

Budgets and all the technicals problems Galileo had aside, would it have been feasible to put a camera on the Galileo atmosphere probe (and why didn't it ever get a separate name?)?

Just imagine the vistas it would have captured. Maybe even the giant floating gas bag life forms drifting by, sifting in their version of krill....

http://davidszondy.com/future/otherworlds/otherplanets/jupiter.htm

Posted by: djellison Sep 8 2005, 01:02 PM

Feasable perhaps, but fairly pointless I'd have thought. You know that bit on a plane flight when you're going thru the clouds and you cant see the end of the wing.....

That - plus the bandwidth from probe-to-orbiter was fairly poor I'd imagine, much like Huygens was.

Doug

Posted by: Dominik Sep 8 2005, 03:04 PM

3.8 Megabit of data was collected. Mostly scientific data from jupiters atmosphere. But I've seen some pictures from the galileo probe mission on TV some years ago. Those pictures were from the cloud structures (Below cloud top). They looked like radar pictures, but the probe did not have a radar.

Thanks for the link djellison. That is, what I was searching for.

Posted by: djellison Sep 8 2005, 03:09 PM

Wow - 3.8 megabits over a couple of hours - that's really poor Imagine the sacrifices for other instruments if they'd just have had something as simple as the Huygens camera suite onboard.

Like many misisons I'd like to see, and places I'd like cameras to go - the cloud tops of Jupiter for instance...we're just not quite at the technical level to do it at anything like a reasonable budget really.

Doug

Posted by: Dominik Sep 8 2005, 04:30 PM

I think, that a camera would have been crushed by jupiters dense atmosphere. But imagine the pictures from below the clouds. They must be amazing!

I hope, that the next mission to jupiter would contain a probe with cameras on board.

By the way, the duration of the mission was 58 minutes.

Posted by: ljk4-1 Sep 8 2005, 04:34 PM

While I certainly knew that the probe would not survive very deeply into Jupiter's atmosphere, it probably would have had a few clear zones to image in - just imagine what vistas it would have recorded for us.

So if we made a probe out of carbon buckyballs and ultra-titanium, how deep and how long do you think it would last?

Posted by: DDAVIS Sep 8 2005, 04:42 PM

[quote=Dominik,Sep 8 2005, 04:30 PM]
I think, that a camera would have been crushed by jupiters dense atmosphere. But imagine the pictures from below the clouds. They must be amazing!

I hope, that the next mission to jupiter would contain a probe with cameras on board.

Absolutely, there may be things of interest for atmospheric scientists to see in such images far more rewarding than the 'squiggly line science' supplied by past such technology. Seeing the SRB videos as they pass through the atmosphere to the ocean whets my appitite to see similar views on the way down in other worlds, even with one color NTSC resolution frame a minute! In a discussion in the 'planetary Sciences' group hardly anyone seemed interested in putting cameras on gas giant probes, perhaps there is a 'mentality of poverty' on such things.

Don

Posted by: JRehling Sep 8 2005, 04:44 PM

The subcloud "pictures" I think you are referring to were reconstructed images based on models made from the Galileo *Orbiter*. Images made in different methane bands bring out detail from different depths. Those "visualizations" assumed that the clouds form three discrete thin sheets with clear air between them. Then they were colored. You can see lots of them here:

http://www2.jpl.nasa.gov/galileo/sepo/atjup/atmos/latitude.html

A descent probe into Jupiter has such limited bandwidth opportunity, and such limited payload mass, with such uncertain prospects for seeing *anything* that it is hard to rationalize a camera. The Galileo Probe instrument payload was about 25 kg or a bit more than that. Huygens's camera was 8.5 kg -- what third of Galileo's payload would you have gotten rid of to get what might be one or two totally featureless pictures, and even in a good case might have looked like BW pictures of terrestrial cumulus clouds?

Posted by: Dominik Sep 8 2005, 05:10 PM

I saw exactly those pictures on TV. Amazing!

NASA has so many great pictures, the problem is to find them. Sometimes it's not so easy...

Posted by: DDAVIS Sep 8 2005, 05:18 PM

A descent probe into Jupiter has such limited bandwidth opportunity, and such limited payload mass, with such uncertain prospects for seeing *anything* that it is hard to rationalize a camera. The Galileo Probe instrument payload was about 25 kg or a bit more than that. Huygens's camera was 8.5 kg -- what third of Galileo's payload would you have gotten rid of to get what might be one or two totally featureless pictures, and even in a good case might have looked like BW pictures of terrestrial cumulus clouds?

Well, future probes may well have better data bandwidth than what you are used to. I don't see uncertainty about what a camera would see as good reason to assume a camera isn't desirable.

this may be apocrophal but I recall in my USGS days hearing talk about a debate on whether the Pioneer F abd G spacecraft should have any imaging capability at all, after all, what could possibly be interesting about cloud tops? As it was the imaging Photopolerimeter was a cheap crappy substitute for a camera which was better than nothing, but outclassed by the real cameras the Voyagerws later carried.

Don

Posted by: ElkGroveDan Sep 8 2005, 05:28 PM

Much longer than the camera

Posted by: ljk4-1 Sep 8 2005, 07:13 PM

They also assumed the Mercury astronauts wouldn't want to look out a window of their spacecraft, either.

Nothing sells space exploration like optical images.

As for a camera on an Jupiter atmosphere probe, how about an infrared one for cutting through the haze and clouds?

Posted by: um3k Sep 8 2005, 07:39 PM

But then what would there be to look at?

Posted by: ljk4-1 Sep 8 2005, 07:45 PM

The, uh... alien invasion fleet hiding in the clouds?

The big jellyfish AC Clarke and Sagan and Salpeter wrote about?

A McDonald's?

Posted by: mike Sep 8 2005, 10:06 PM

Who knows. That's the idea, to find out what is under there. Maybe nothing, probably something. I'm not knowledgeable on whether it's possible to have an IR probe that cuts through cloud and haze but bounces off of more solid matter, but the basic idea makes sense, RADAR or whatever.

Surely you agree that gravity causes things to coalesce, and that therefore if Jupiter is gas so far away from the core, the (massive) core must be rather more dense?

Posted by: JRehling Sep 8 2005, 11:15 PM

In itself, uncertainty about what the camera would see is not a reason to scratch it from the payload list, but when mass is also an issue, we'd have to opt for an instrument that definitely has a point over one that merely might.

We can say with certainty that some images in a jovian descent would occur inside clouds and therefore be blank. Others would almost certainly have to look like Earthly cloud formations (as jovian clouds do from orbit) -- sometimes showing structure, sometimes just a blank wall. Indeed, I can imagine we would learn something from an image snapped at the right place and time, but flying through terrestrial clouds shows us how time/location-varying that will be, information-wise.

Bandwidth ought to follow Moore's Law, and with Galileo designed 30 years prior to any followup, we can expect the bandwidth issue to go away, but not the mass issue. Given that, the middling probability of getting *any* result is pertinent. I look at expected value, and a middling probability of something useful loses to a sure probability of something else useful.

Simply put, a camera is going to add to the cost of an entry probe, so we have to see how the expected science gain would fare as a function of cost. I'd love to see the pictures -- believe me, I enhanced one of those simulated images to make it look more realistic and made it my wallpaper -- but it's going to be a while before that wins out as a priority.

I wish they had tried something like the following with the Galileo *orbiter*: create a mode of turning off all safe modes; design a super close flyby of the cloud tops on a *penultimate* pass of Jupiter; transmit the resulting image(s) to Earth before the final plunge. If this failed (and I could well imagine that it would), at least we tried.

Posted by: JRehling Sep 8 2005, 11:22 PM

There should be no doubt that Jupiter has interesting "stuff" in its depths, but probing it from point-blank electromagnetic sensing (IR, microwave, radar, whatever) may not perform particular explorations the way we wish.

It is very unlikely that *any* EM sensing will penetrate more than a small fraction of the planet's depth. A few thousand km of air will still block light. We'd likely see an isotropic (ie, blank) field in most any wavelength. Exceptions would be:

1) Thermal wavelengths: We could see heat and cooling in updrafts, but really this sort of thing is more appropriately done from orbit. The intricacy of the structure of such updrafts and downdrafts is unlikely to be featured well from inside the atmosphere. You might see one or two "features" in the immediate vicinity, but if the atmosphere is heterogeneous in this respect, you wouldn't see very much, very far.

2) Unusual "clouds", deeper down, of compounds that we don't think of as volatiles. There could be sulfur, or even iron (etc) clouds at great depth. I don't know -- possibly a probe could go deep enough to radar scan for those? The feasability is questionable.

Posted by: Sunspot Sep 8 2005, 11:41 PM

There were also problems with the Galileo orbiter not too long before it arrived. The tape recorder got stuck, and I believe they cancelled all the probe entry site observations. No one knows for sure what the area the probe came down into looked like.

Posted by: Dominik Sep 9 2005, 05:23 AM

I remember, that there was a picture of jupiter, that shows the entry point of the galileo probe...

EDIT: I've found it.



Hi-Res:
http://hubblesite.org/gallery/album/entire_collection/pr1995046a/web_print

But this picture is from hubble...

Posted by: edstrick Sep 9 2005, 07:59 AM

"Bandwidth ought to follow Moore's Law, and with Galileo designed 30 years prior to any followup, we can expect the bandwidth issue to go away, "

Bandwidth is not determined by mass, power requirements and cpu speed of electronics but by frequency, transmitted power, directionality of transmission, area of receiving antenna and sensativity / signal to noise of receivers, including encoding of the signal to make it noise resistant. There were rapid improvements in receivers and encoding from the early 60's to the mid 70's but improvements since then have mostly been done by upping the frequency of signals to make transmitters more directional. Back in late 70's, they were doing usable telemetry with a signal to noise level rather less than 1.0, and were and are pretty much at theoretical limts set by physics.

Posted by: mike Sep 9 2005, 05:14 PM

That doesn't seem fair, to have a huge ball of matter floating nearby and no way to examine most of it. Surely there's some way to take a look, perhaps with methods we haven't yet discovered/devised.. Maybe Jupiter will just have to wait a while.

I'd personally like to see a camera-equipped probe descend into Jupiter, just because the pictures would be utterly unique if nothing else - even if they are just undifferentiable walls of white, they're undifferentiable walls of white from Jupiter. We'd have to see something, and I think that something would be worth the effort. I'll pony up the $300 kajillion myself. If that's not enough, we can use some of that 'blowing people up' money of which we possess so much...

Posted by: JRehling Sep 9 2005, 06:45 PM

I would liken the problem to seeing the core of the Earth. Can't be done. The only two ways to probe that are with thumps and gravity. Sensing the gravitational field is part of the Juno mission, so look forward to it! Thumping a gas is harder than thumping a solid. I suppose we could "sound" Jupiter by setting off a hydrogen bomb and listening for the sound reflection at a second site, separated by some fraction of Jupiter's circumference away. If we had the capability, it would be ideal to have a probe (or more than one!) listening at the same time as another comet hits the planet, but those events are few and far between. You can't really count on an entry probe being timed precisely enough (the margins are very tight), so a dirigible would be necessary. Maybe a long-lived nuclear powered hot air balloon would be possible -- but the hazards are innumerable. Remember that Jupiter's atmosphere has a tiny molecular weight (lower than helium!), so that only heated H2 could float in it, and provide meager buoyancy per volume of balloon.

Once you had something long-lived, a camera would seem a lot more worthwhile, as the high probability of getting a bland image would eventually give way to a good side-looking shot of a cloud formation. But it would still have to fit into the mass margins of what would have to be a small payload once you had a balloon big enough to loft a nuclear reactor, and this large and therefore flimsy balloon would have to face incredible wind shear sooner or later. I don't know if it's even possible to hope for a lifespan beyond hours. Surviving one rotation of the planet would be fantastic.

Given another comet strike with enough advance warning, we could hope to plop a dirigible or two in there and get the sounding data, maybe even several distinct ones if the impactor is fragmented like Shoemaker-Levy was. Nature is not forced to cooperate with this plan, however, which is already baroque.



You can pretend these are from Jupiter:

http://www.backgroundcity.com/groups/g7.html

Posted by: mike Sep 9 2005, 07:34 PM

I think we, or something we create, will eventually go to the core of the Earth. I also think we'll somehow get something or other into Jupiter. Of course, by the time we can do these things they may seem rather trivial and meaningless..

And those clouds don't count, sorry.

Posted by: DDAVIS Sep 9 2005, 08:35 PM

I'd personally like to see a camera-equipped probe descend into Jupiter, just because the pictures would be utterly unique if nothing else - even if they are just undifferentiable walls of white, they're undifferentiable walls of white from Jupiter. We'd have to see something, and I think that something would be worth the effort.

Obviously I agree, because of the PR value of a good image we might get. Cameras can be made quite small these days, and in the years ahead they can be made lighter and smaller. Images are worth far more in stimulating public interest than many volumes of 'squiggly line science'. Again, I ask people to look at the SRB descent videos and imagine seeing similar sequences from other worlds!
Here is a composite image from a panning scene in my Galileo animation for Ames showing probe sunset during its descent:

Posted by: mike Sep 9 2005, 09:47 PM

Striking. Jupiter is so huge I'm not sure I can really comprehend it.. Pictures would help.

Posted by: David Sep 9 2005, 10:05 PM

And given that, at Jupiter's cloudtops, everything weighs more than two and a half times what it does no earth, you'd need something extraordinarily light. The task might be more practical on Saturn, where the gravity is less than earth's.



I wouldn't expect that an entry-probe with an imager would provide very spectacular images from inside the clouds (though I'd be happy to be wrong); but if one had a downward-pointing camera, you could get invaluable images from the approach to the cloudtops, at much higher resolution than anything we have now, something like the approach images from Titan. Obviously they'd be more interesting if you dropped the probe into a raging storm, instead of a bland cloud-band!

Posted by: JRehling Sep 9 2005, 10:20 PM

That also means the buoyancy is less. Hint: If you had a bathtub on Jupiter (filled with water and surrounded by STP air!), the same things would float there as on Saturn/Earth/Moon/Phobos/etc.
Unless you're worried about the thing falling apart under its own weight, the local g divides out.
In fact, Saturn's atmosphere is slightly lower in molecular weight than Jupiter's, making buoyancy there a bit harder.



My own terrestrial experience is that side-looking views of cloud formations can be pretty striking as you see the topside profile of them against the sky. One difficulty on Jupiter would be that there might be similarly-hued clouds behind those (there are layers on layers). Another thought is that the clear air above and between layers would still have some humidity (from various species), and even on a clear day, you can't see forever. A couple of hundred kms' line of sight would probably yield blankness no matter what cloud/sky mix were behind it -- although the "humidity" of a parcel of Jupiter air would have to vary depending upon... many things. A view might show the tops of local fluffy cumulus in front of what seems to be a blue sky that actually has lots more clouds behind it, but too far away to see through the vast distances of "air".

Another thought on in-cloud imaging is that onboard processing might be used to choose which of many images are worth sending up (the less blank the better). Thus, a probe might take dozens of images, then send one or a few later, before it dies.

Personally, the thing I'd most like to "see" from a dirigible would be mass spectrometry from cloud particles at all heights, and to find out what the coloring agents are in the clouds.

Posted by: pioneer Sep 23 2005, 04:07 PM

Although having a camera on the probe would have been interesting, it would have the following problems in addition to the mass and cost:
1) The area around the probe would have gotten dark quickly as the probe descended
2) The probe experienced severe turbulence as it made its way down, so the images would have been smeared

Posted by: tty Sep 23 2005, 06:09 PM

A hydrogen bomb might actually be better than an asteroid since it could be built to withstand very high pressures and drop quite deep into the atmosphere before going off (a B61-11 "bunker-buster" perhaps?). It would be rather heavy though and to reap full benefit of such an experiment you would need several widely spaced probes to analyze the echoes.
Perhaps we'll find some really good way of detecting neutrinos instead, then we could look at the core of the Sun instead...

tty

Posted by: Decepticon Sep 23 2005, 10:41 PM

As a child I remember being so upset that the probe had no camera. Now I look back and laugh.

I even remember shedding a tear when I heard about the antenna faluire.

Posted by: Bob Shaw Sep 23 2005, 10:50 PM

What we need is volunteers.

And hang-gliders...

Posted by: edstrick Sep 24 2005, 07:14 AM

For imaging from a Jupiter descent probe, you would want to pick a reflected sunlight channel with as little methane absorption AND as little gas (rayleigh) and haze scattering as possible. That way you'd get the greatest contrast in atmosphere and cloud structures.

In addition, you'd want to have a middle-infrared imaging channel in the 5 micrometer band. That band has the greatest atmosphere transparency at wavelengths shorter than microwaves or decimeter waves, and is what shows the atmosphere hotspots best in earthbased images. Sunlight is weak in the 5 micrometer band and Jupiter's appearance is controlled by thermal emission from the deep atmosphere leaking up through the clouds of varying opacity.

Posted by: bkellysky Jan 16 2018, 02:54 AM

Did anyone put together an animation of the data from the Galileo Probe, like was done for Huygens' plunge into Saturn's atmosphere?

Posted by: JRehling Jan 16 2018, 04:01 PM

The Galileo Probe took no images, so it doesn't have any equivalent data. We have a time/depth/pressure profile, which probably makes a better graph than it does video.

It appears clear, in retrospect, that the GP hit a relatively dry, clear, cloudless patch in Jupiter's atmosphere. A camera might have seen nothing clear whatsoever once it had descended sufficiently. It could have been all blue and gray haze.

Posted by: bkellysky Jan 16 2018, 04:35 PM

Thank you, JRehling, for the note.
I know the Galileo Probe didn't take photos, so maybe a single (long!) graph may be enough.
I haven't seen that so far, but yahoo searches don't find lots of stuff that's out there, perhaps it's in a technical paper.
I had hoped there would be more data to display from the variety of instruments, but I'm guessing, with the slow bit rate, the data may be better as a graph than an animation. We had lots of fun with the Huygens movie - projected it on a three-story high wall in our drill floor for Aerospace Education at Civil Air Patrol!

Thanks!
bob

Posted by: djellison Jan 16 2018, 06:15 PM

Well - the data is all here : http://pds-atmospheres.nmsu.edu/PDS/data/gp_0001/data/

Wouldn't take much to start graphing some of it.

Posted by: JRehling Jan 16 2018, 08:38 PM

That sounds like a great way to experience it, Bob!

This graph seems to hit the highlights of what the GP found:

http://ircamera.as.arizona.edu/Astr2016/text/sminew.jpg

The chart here has the composition as measured by GP:

https://en.wikipedia.org/wiki/Atmosphere_of_Jupiter#Chemical_composition

The way it's presented, you have to do some math to find the composition by volume / partial pressure. Everything except the inert gases will be found almost always as the simplest compound with hydrogen, e.g., nitrogen as NH3.

Juno has found that the values found by probing a single location may in many cases differ from other locations. On Earth, this is true for the local prevalence of water, which we parcel out as the variable known as humidity and speak of the relatively constant composition of "dry air." On Jupiter, it looks like NH3 and H2O, at least, both vary considerably with location.

Posted by: bkellysky Jan 16 2018, 10:29 PM

Thanks for the directions- I'll check it out.

bob