Io, Still A Mystery Moon Options

[volcanopele]

http://www.planetary.org/blog/article/00000692/

Rosaly Lopes has a new blog post on the Planetary Society blog on the mysteries still surrounding Everyone's Favorite Moon (and if it isn't your favorite moon, then may a giant, falling chunk of komatiite greet you ). She aludes to the upcoming observations by New Horizons to study surface changes and volcanic activity on Io, and to an upcoming book, on Io. The book, Io After Galileo, is currently on Amazon, but rest assured, it will be available until early 2007.

here is a link to the book's Amazon.com page:

http://www.amazon.com/Galileo-Springer-Pra...TF8&s=books

[Guest_AlexBlackwell_*]

Thanks for the heads-up, Jason. I also recommend The Volcano Adventure Guide.

[helvick]

(and if it isn't your favorite moon, then may a giant, falling chunk of komatiite greet you

With you there bud, 100%. There is only one moon that is truly a _real_ moon, eh. Take your dwarf panets and smoke them but Io will remain the one really genuine active extraterretrial for some time to come. Yeeeeeehaaaaw.

[David]

With you there bud, 100%. There is only one moon that is truly a _real_ moon, eh. Take your dwarf panets and smoke them but Io will remain the one really genuine active extraterretrial for some time to come. Yeeeeeehaaaaw.

Titan? Enceladus? Triton? E____a?

[nprev]

Seems like a good time to ask the question, "How would you design a mega-radiation-hardened Io orbiter?" I can't imagine, frankly...only thing I can think of is about 5000 KG of electron tubes and one hell of a set of RTGs!

[ljk4-1]

Speaking of Io mysteries: Remember the 1981 SF film Outland, which took place on
a mining colony on that moon?

In the station manager's office was a large globe of Io on his desk.

I want to know the following:

1. Who made it?

2. How accurate was it for the time (just after the Voyagers)?

3. What became of it?

http://www.paper-dragon.com/rns/outland/index_.html

http://www.martinbowersmodelworld.com/html/outland.html

http://twtd.bluemountains.net.au/Rick/outland.htm

[Mariner9]

I look forward to owning this book, it looks awesome.

On a similar note, last Christmas I asked for (and got) another Springer-Praxis book:
Europa: The Ocean Moon.

An incredible book, with a lot of pictures (particularly mosaics) that I had not seen before.

Check it out. And it's only 90 bucks.... a comparative bargain.

[volcanopele]

I have that book too. It is okay, but it makes vexgizmo look not so nice... Could have done with more science, and less "Rick Greenberg's fight against the Man". "Io after Galileo" is more like a collection of overview papers, presenting the current state of knowledge, with each chapter written by a different set of authors. "Europa: The Ocean Moon" is more about Rick Greenberg's argument that the Europa icy crust is thin, and that all other arguments are just the status quo story by the establishment...

[stevo]

(and if it isn't your favorite moon, then may a giant, falling chunk of komatiite greet you ).

I'd love to agree, but my favorite moon has to be one that I (OK, my descendants) have a better chance of setting foot on. That being said, I used to have Io as the wallpaper on my laptop and I would test people before I gave presentations. I gave up because they kept guessing it was a pizza.

[Mariner9]

Yeah, the author of The Ocean Moon definately had an ax to grind.

Without both sides of the argument being presented in the book, I'm hesitant to take a side. But I have seen a lot of other "instant science" analysis in planetary science over the years that later was either completely discounted or felt to be a gross oversimplificatin. And I've been hearing complaints from the scientific community for years that NASA spends all the money on the mission, spends 15 minutes analyizing 20% of the data, and them moves on to the next destination.

But if you slip past the periodic " the initial analysis by so-called experts in the wrong field were completely wrong" portions of the book, it still makes for a fascinating read. I came away from the book seriously doubting the absolute necessity of an Europa orbiter preceeding a lander. I thought he made a pretty good case that we know more about Europa than many experts would have you believe.

I keep hoping that the next New Fronteirs mission is an "Io Observer" .... a multiple flyby mission to build on the Galileo results, and take a few flybys of Europa while it just happens to be in the neighborhood. I can't shake my doubts that the Europa Orbiter is turning into the latest version of "Mars Sample Return" and "Comet Rendesvous" .... missions endlessly studied and promoted as "the highest priority" .... but never flown.

[Guest_Myran_*]

ljk4-1 wrote: Speaking of Io mysteries: Remember the 1981 SF film Outland, which took place on
a mining colony on that moon?

Hello again. You are correct and I remember the film that I did see in the movie theater here.
I have earlier mentioned my lifelong friend with a space interest here, yes he was sitting in the chair next to mine nudging me asking questions of what I thought about the details. This was at a time when we worked together as undertakers. Enough look backs for me - get on with it!!

Sean Connery starring in a film about a moon that was a subject almost everyone's lips after the discovery of the violent vulcanism - irresistable combination!
The film made in UK, directed and adapted by Peter Hyams.
The spacesuits seemed to me to be thin for such a heavy radiation environment and I had a hard time accepting those when I watched - but on the other hand, if they only used those in the mine underground.
One detail I remember was a sort of grid outside the base. At first I didnt understand what the function was until in a fight one assasin did drop off and skitted down it sparks flying. I got the idea that it was supposed to be for power tapping energy from Jupiters radiation belt.
So at the time I accepted Outland to be good sciense vice from what we knew back then, I was even suprised they gotten it so up to current knowledge - on the other hand there were not much shown of the actual surface of Io from what I can remember.

[martin peters]

The utter mystery of Io certainly is mind-boggling, and this satellite definitely makes my top 10. Had to chuckle at Stevo's anecdote about "pizza-face" Io

Paul Schenk and others have written about the "surprisingly low relief" of the regions surrounding the hot spots. Paul noted that unlike Mars with its great shield volcanos, Ra Patera, the largest shield volcano on Io, was only 1 km high and its slope was <0.5 deg.

Looking at the images that have become available (huge thanks to the imaging teams for providing them and to the community of amateurs and professionals alike for producing a variety of enhanced versions), it just seems to me that the regions near the active hot spots are shaped like lakes. So the question is: "What is the evidence by which we know that the flowing material (whatever it is) is flowing away from and not toward the active regions?

martin

[tedstryk]

While we are on this topic, there is a great new release on the photojournal.

http://photojournal.jpl.nasa.gov/catalog/PIA09257

[jasedm]

This would seem to be the best place to ask this question - does Io have any officially recognised impact craters at the available resolution achieved by the Galileo probe?
Having searched the net, all the resources available state that Io has "very few if any" or "almost none" or "none"
I've been unable to find any images which unequivocally show an impact structure.
The only other solid body so far imaged reasonably closely which shows none at all is Atlas, and that is presumably due to continuing accretion of ring particles, and the shielding effect of the F-ring for projectiles coming in equatorially to Saturn.

[volcanopele]

No, to date no obvious impact craters have been identified on Io. There have been a few features that have been suspected as such, such as a pit in northern Zal Montes, but these are better explained by other processes, like sapping. Another suspected impact feature is a circular feature within Heno Patera, but our current data at this volcano is of too low resolution to confirm this.

[jasedm]

Thanks VP.
I thought I'd seen an image some time back of an Ionian crater, but I think it may have been an old Voyager shot of an Europan one (Pwyll maybe).

[MarcF]

New data for an old topic:
Three massive volcanic eruptions occurred on Jupiter's moon Io within a two-week period in August of last year.
http://www.nasa.gov/jpl/news/jupiters-moon...0804/index.html
"We typically expect one huge outburst every one or two years, and they're usually not this bright," said Imke de Pater, professor and chair of astronomy at the University of California, Berkeley, and lead author of one of two papers describing the eruptions. "Here we had three extremely bright outbursts, which suggest that if we looked more frequently we might see many more of them on Io."

"These new events are in a relatively rare class of eruptions on Io because of their size and astonishingly high thermal emission," Davies said. "The amount of energy being emitted by these eruptions implies lava fountains gushing out of fissures at a very large volume per second, forming lava flows that quickly spread over the surface of Io."

Regards,
Marc.

[Toma B]

Io is definitely my favorite moon of Jupiter if not in all Solar System.
I was just wondering is there a possibility to acquire good images of Io once Juno gets to Jupiter in July 2016?

[Bjorn Jonsson]

This has been discussed elsewhere and the answer is no. Junocam is a wide angle camera - at a distance of e.g. ~500,000 km from Io Junocam's resolution is ~400 km/pixel. There will be no close flybys of the Galileans, this is a mission that's focused on Jupiter.

[mcaplinger]

There will be no close flybys of the Galileans...

Correct. In the nominal orbit the closest approach to Io is a little under 200,000 km.

[Phil Stooke]

Right... but to be more specific, a previous calculation was that Io at best would appear only 16 pixels across. That's not much, but it will allow large features to be seen, including large eruption deposits. It is reasonable to expect that the small number of images we might expect from the closer passes by Io will let us see a few recent surface changes, such as the effects of the big eruptions just reported.

Phil

[volcanopele]

To be honest, ground-based observatories can do a better job. That being said, the IR instrument on Juno could acquire useful data over Io's polar regions.

[tedstryk]

I would imagine that some of the plumes might look neat at a high phase angle even at such low resolution. I wonder if it would be possible to take some framelets of Io on a few successive rotations for stacking purposes to reduce noise and maximize usability. And it would seem that at its closest, should that be looking down at a pole, it would still be moderately useful for looking at albedo changes in those foreshortened regions.

[mcaplinger]

a previous calculation was that Io at best would appear only 16 pixels across.

The Junocam images of the Moon during Earth flyby are very similar to the best approaches of Io in terms of size and resolution.

It's too early to say what the satellite encounter distances and times will look like for the real mapping orbit. By intent we don't get that close -- see http://www.trylam.com/files/AIAA_2008-7368...uno_Mission.pdf

[jccwrt]

Sorry if this is the wrong thread, but I didn't see one about the reprocessing of Io images.

As you may know, some of the Voyager 1 images taken during the Io flyby are heavily smeared due to movement of the scan platform. Thanks to machi's tip about using the Parallel Iterative Deconvolution plugin for imageJ, I realized that some of these heavily smeared images could be restored to at least some degree.

Just as Voyager 1 was about to make its closest approach, it took two three-frame longitudinal scans of the Moon, centered at around 300 degrees west and 5 degrees west. Judging from volcanopele's mosaic page, these images have a resolution somewhere around 400m/px. (Jupiter Viewer seems to output a wrong range to Io - 400,000 km - so I can't use that to calculate the resolution better).

So without further ado, the deblurred mosaics:


Io Longitudinal Scan 1 by Justin Cowart, on Flickr


Io Longitudinal Strip 2 by Justin Cowart, on Flickr

The most severe smearing was in the first frame of each sequence, so I'm guessing that's a result of imaging before the scan platform had entirely stabilized after slewing. Unfortunately I wasn't able to recover fine detail, but some of the larger features spanning several pixels have been recovered to some degree. At any rate I'm just happy to see some fresh new Io pictures I hadn't seen anywhere else on the web!

[machi]

Nice work!
In terms of freshness those aren't the first attempts to reprocessing those images.
Some of older images are here.
I did few mosaic, Bjorn Jönsson did few of them, Jason (Volcanopele) did lots of them (best high-res global mosaics of Io on the net) and Paul Schenk did exquisite mosaics for his Atlas of the Galilean Satellites.
There are probably even more of them from other authors.

[jccwrt]

Thanks for those links! I'd done some googling and searches though the various Io threads in this subforum for other examples of these pictures and came up empty-handed.

I'd really also like to thank you for sharing that tip about Deconvolution, using it feels like I've been turned into a wizard with magical image restoration powers!

[tedstryk]

Amazing work! The Voyager 1 smears have been a set that I've never been able to crack. I've never been able to get rid of the smear without destroying detail visible from the part of the exposure that wasn't smeared.

[Bjorn Jonsson]

Great mosaics! I ran into somewhat similar problems when desmearing some of the less smeared Ganymede images - maybe the scan platform motion is more irregular in these images than in the more smeared images, thus making the less smeared images more difficult to desmear (contrary to what one would expect).

[jccwrt]

I worked on one of the approach sequences taken by Voyager 1 on March 4, 1979. I believe that these series of images was the one where Linda Moribito noticed the faint eruptive plume from Pele and discovered Io's volcanic activity.


Full-size here

I got a slightly better S/N ratio on the images because there were three clear filter images, and two images through each of the filter sets. I used the OGV combination. I've boosted the brightness and contrast of the space around Io a little to make the plume a little more obvious.

It's striking how much brighter Pele's plume is at UV and blue wavelengths. Is that more from the sulfur content, or is there a psuedo-auroral emission from the ionizing radiation?

[Paolo]

II believe that these series of images was the one where Linda Moribito noticed the faint eruptive plume from Pele and discovered Io's volcanic activity.

Io's activity was detected in an optical navigation long exposure image taken after the flyby (and thus showing the nightside of Io)

[jccwrt]

Io's activity was detected in an optical navigation long exposure image taken after the flyby (and thus showing the nightside of Io)

Ah, thanks for the correction. I guess that makes this a pre-discovery observation then. I'm a bit amazed it wasn't noticed earlier, then!

[dtolman]

Swedish amateur astronomy Jesper Sandberg identified the first possible impact crater ever found on Io, while studying Galileo imagery of the moon.
Poster presentation at AGU 2023 (grabbed from twitter)

[Phil Stooke]

That is great! A very nice discovery.

Phil

[Explorer1]

Now to bet on how long it lasts....

[Bjorn Jonsson]

This is the Galileo image showing the possible impact crater:



The possible crater is the small dark spot at center near the top.

[dtolman]

Close up shot of the possible crater - from an article on the discovery