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Complete Science Data Of Galileo Probe Mission?
pioneer
post Sep 23 2005, 04:07 PM
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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
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tty
post Sep 23 2005, 06:09 PM
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QUOTE (JRehling @ Sep 9 2005, 08:45 PM)
I would liken the problem to seeing the core of the Earth. Can't be done.

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.


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... smile.gif

tty
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Decepticon
post Sep 23 2005, 10:41 PM
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QUOTE (tty @ Sep 23 2005, 02:09 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...  smile.gif

tty
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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.
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Bob Shaw
post Sep 23 2005, 10:50 PM
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QUOTE (Decepticon @ Sep 23 2005, 11:41 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.
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What we need is volunteers.

And hang-gliders...


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Remember: Time Flies like the wind - but Fruit Flies like bananas!
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edstrick
post Sep 24 2005, 07:14 AM
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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.
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bkellysky
post Jan 16 2018, 02:54 AM
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Did anyone put together an animation of the data from the Galileo Probe, like was done for Huygens' plunge into Saturn's atmosphere?
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JRehling
post Jan 16 2018, 04:01 PM
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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.
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bkellysky
post Jan 16 2018, 04:35 PM
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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
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djellison
post Jan 16 2018, 06:15 PM
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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.
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JRehling
post Jan 16 2018, 08:38 PM
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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...cal_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.
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bkellysky
post Jan 16 2018, 10:29 PM
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Thanks for the directions- I'll check it out.

bob
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