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Unmanned Spaceflight.com _ Jupiter _ Io Blog

Posted by: volcanopele Feb 26 2008, 08:50 AM

Just let you all know about a new blog I've started called The Gish Bar Times located at http://gishbar.blogspot.com/ . I intend to use the blog to cover Io-related news like new papers or abstracts, developments with the flagship mission selection process, newly processed images, volcano news, or pretty photos taken of Io and Jupiter. I hope you all enjoy!

Posted by: ngunn Feb 26 2008, 11:32 AM

QUOTE (volcanopele @ Feb 26 2008, 08:50 AM) *
Just let you all know about a new blog I've started called The Gish Bar Times


That's great, but please continue to post links here to updates there.

Posted by: Stu Feb 26 2008, 12:06 PM

Nice one... saved as a Favourite already! Looking forward to seeing more of your excellent images there.

Posted by: centsworth_II Feb 26 2008, 03:12 PM

QUOTE (volcanopele @ Feb 26 2008, 03:50 AM) *
Just let you all know about a new blog I've started called The Gish Bar Times....

Judging from your Europa article (and graphic laugh.gif ) I guess you're
in the "Mission to Titan" camp. smile.gif

Posted by: Juramike Feb 26 2008, 04:04 PM

Excellent!!!

I look forward to reading your postings!

-Mike

Posted by: Gsnorgathon Feb 26 2008, 09:26 PM

I'm very glad to see you return to blogging, Jason. This is good news!

Posted by: Decepticon Feb 27 2008, 09:10 AM

rolleyes.gif

QUOTE (centsworth_II @ Feb 26 2008, 10:12 AM) *
Judging from your Europa article (and graphic laugh.gif ) I guess you're
in the "Mission to Titan" camp. smile.gif


Posted by: Big_Gazza Feb 27 2008, 10:29 AM

A Europa-free zone? Nice to see. laugh.gif

Posted by: nprev Feb 27 2008, 10:47 PM

Give 'em hell, Jason! smile.gif I look forward to your observations (oh, yeah...Down with Europa!!!!) tongue.gif

Posted by: volcanopele Sep 16 2008, 11:20 PM

After a few month hiatus, I have started posting on my blog again with a post covering the major news of the last few months and a few notes on DPS abstracts.

http://gishbar.blogspot.com/

Posted by: volcanopele Jan 21 2009, 08:41 AM

I have done quite a few featured posts in the last few weeks (otherwise known as blog posts that took far too long to compose). In my latest, I talk about the newly released Joint Summary Report for the Europa Jupiter System Mission: http://gishbar.blogspot.com/2009/01/europa-jupiter-system-mission-summary.html

Posted by: volcanopele Jan 22 2009, 01:34 AM

I have gone ahead and posted that summary of potential Io science from EJSM:

http://gishbar.blogspot.com/2009/01/io-science-with-ejsm.html

Posted by: volcanopele Jan 28 2009, 04:33 AM

I've put up a couple of new posts on http://gishbar.blogspot.com/2009/01/paper-ios-atmospheric-dynamics-during.html and http://gishbar.blogspot.com/2009/01/boosaule-montes.html.

Posted by: volcanopele Jun 17 2009, 01:27 AM

Last couple of weeks, I've put up a few posts on the mutual event eclipses that have been occurring in the Jovian system the last few weeks, particularly the eclipses of Io by Ganymede. Today, I also posted about the 1979 Surt eruption that occurred 30 years ago this week.

http://gishbar.blogspot.com/2009/06/todays-eclipses-of-io-by-ganymede.html
http://gishbar.blogspot.com/2009/06/another-total-eclipse-by-ganymede.html
http://gishbar.blogspot.com/2009/06/eclipses-of-io-by-ganymede-on-june-16.html
http://gishbar.blogspot.com/2009/06/1979-outburst-eruption-of-surt-30-years.html

Posted by: volcanopele Jul 14 2009, 09:40 PM

Uploaded a new post to the blog about tomorrow's Ganymedean solar eclipse on Io:

http://gishbar.blogspot.com/2009/07/ganymede-eclipse-on-io-wednesday.html

This is the culmination of a series of weekly eclipses by Ganymede on Io. With each weekly eclipse, the center of Ganymede's shadow appears further south on Io. This week, the center of Ganymede's shadow passes just north of Io's equator. Over the next few weeks, ending in late August, the weekly eclipses will be centered over Io's southern trailing hemisphere.

Posted by: volcanopele Sep 19 2009, 11:25 PM

Added a few new posts this week you all might be interested in:

A Summary of a new paper examining spectroscopy of Io's surface as it leaves Jupiter's shadow
http://gishbar.blogspot.com/2009/09/paper-spectroscopy-of-io-eclipse.html

Summaries of the Io DPS 2009 abstracts
http://gishbar.blogspot.com/2009/09/io-talks-at-dps-2009.html

A Look at the final version of the Io Decadal Survey white paper
http://gishbar.blogspot.com/2009/09/final-version-of-io-decadal-survey.html

Posted by: volcanopele Oct 12 2009, 09:34 PM

Sunday was the 10th Anniversary of Galileo's I24 encounter with Io. On the blog, I've been taking a look back at that encounter, first at the planning that went into the encounter and then yesterday I looked at some of the obstacles that Galileo scientists and engineers faced during that encounter:

http://gishbar.blogspot.com/2009/10/galileos-i24-flyby-of-io-look-back.html
http://gishbar.blogspot.com/2009/10/galileos-i24-flyby-of-io-look-back_11.html

Later this week, I will take a look at some of the data returned from that encounter and how it changed our understanding of Io.

Posted by: volcanopele Oct 19 2009, 07:18 AM

Finished up that retrospective on the I24 flyby with an animation of the encounter mixed with the data acquired plus a look at some of the result from the flyby:

http://gishbar.blogspot.com/2009/10/animation-of-galileos-i24-flyby-of-io.html
http://gishbar.blogspot.com/2009/10/galileos-i24-flyby-of-io-look-back_18.html

Posted by: volcanopele Oct 20 2009, 09:59 AM

Well just as I was headed to bed last night, I ran a quick search for papers on Io across all of Elsevier's journals, usually I just following papers posted in Icarus or Planetary and Space Sciences. I came across a paper to be published in the October 30 issue of the Journal of Volcanology and Geothermal Research called, "Volcanic history, geologic analysis and map of the Prometheus Patera region on Io" by Giovanni Leone et al. I read the article this afternoon, and after putting together a nice animated gif of high resolution Galileo NIMS and SSI data of this volcanic flow field, I've gone ahead and posted a summary of the paper on Gish Bar Times.

Enjoy!

http://gishbar.blogspot.com/2009/10/paper-geologic-mapping-of-volcano.html

Posted by: volcanopele Dec 15 2009, 05:27 AM

Sorry I've been ignoring the blog for last few weeks. Blame Modern Warfare 2, no free time outside that and work laugh.gif

Anyways, I've written up a post on another geologic map of Io, this time covering the Hi'iaka and Shamshu regions of Io:

http://gishbar.blogspot.com/2009/12/paper-geomorphologic-mapping-of-hiiaka.html

Posted by: volcanopele Jan 6 2010, 01:09 AM

With the 400th Anniversary of the discovery of Io and the other Galilean satellites coming up on Thursday, this week I am doing a series of posts on Galileo's discovery, Simon Marius's claim, and the discovery of the moons in the history of astronomy:

Io@400: The 400th Anniversary of Galileo's Discovery of the Galilean Moons
Overview post for the Series
http://gishbar.blogspot.com/2010/01/400th-anniversary-of-galileos-discovery.html

Io@400 Part 1: Copernicus, Galileo, and the Telescope
The state of astronomy at the start of the 17th Century, the invention of the telescope, and Galileo's early innovations with it
http://gishbar.blogspot.com/2010/01/io400-part-1-copernius-galileo-and.html

Io@400 Part 2: Looking through the telescope in 1609
Galileo and Thomas Harriot's observations of the Moon and nebulae in 1609
http://gishbar.blogspot.com/2010/01/io400-part-2-looking-through-telescope.html

Over the next three days, I will update my blog with three more posts, including a post on Simon Marius's claim tomorrow, the discovery of the Galilean satellites by Galileo on Thursday, and Galileo's Sidereus Nuncius and its effect on the scientific community in 1610 on Friday.

Happy Io Discovery Day!

Posted by: volcanopele Jan 9 2010, 12:02 AM

Okay finished those other three parts:

Io@400 Part 3: Simon Marius and the Mundi Iovialis
http://gishbar.blogspot.com/2010/01/io400-part-3-simon-marius-and-mundus.html

Io@400 Part 4: 400 years ago today, Cosmica Sidera
http://gishbar.blogspot.com/2010/01/io400-part-4-400-years-ago-today.html

Io@400 Part 5: The Starry Messenger
http://gishbar.blogspot.com/2010/01/io400-part-5-starry-messenger.html

Enjoy!

Posted by: john_s Jan 11 2010, 05:36 PM

Thanks again, Jason, for those great summaries of the work of Galileo and his contemporaries.

A question that interests me is when the Laplace resonance (the 4:2:1 ratio of the orbital periods of Ganymede, Europa, and Io) was first noticed and what people made of it at the time. Laplace explained the resonance much later, in the 1700s. You would think the resonance would have been noticed very early, given the great interest in the Galilean satellites at the time, especially their importance for navigation. You would also expect a lot of speculation on the meaning of the resonance once it was noticed. But I haven't heard any discussion of this.

John

Posted by: DrShank Jan 11 2010, 06:02 PM

QUOTE (john_s @ Jan 11 2010, 11:36 AM) *
Thanks again, Jason, for those great summaries of the work of Galileo and his contemporaries.

A question that interests me is when the Laplace resonance (the 4:2:1 ratio of the orbital periods of Ganymede, Europa, and Io) was first noticed and what people made of it at the time. Laplace explained the resonance much later, in the 1700s. You would think the resonance would have been noticed very early, given the great interest in the Galilean satellites at the time, especially their importance for navigation. You would also expect a lot of speculation on the meaning of the resonance once it was noticed. But I haven't heard any discussion of this.

John



that would have been a good question at the conference last week, as there was a fair body of historical experts there . . .

Posted by: volcanopele Feb 23 2010, 07:32 PM

The Gish Bar Times is nearing its 2-year anniversary on Thursday, and with that I want to announce a new URL for the blog: http://www.gishbartimes.org . The old blogspot url will still work, so you don't have to change you bookmarks if you don't want to.

For those who are not regular visitors, lately I have been looking at http://gishbar.blogspot.com/2010/01/lpsc-2010-abstracts-now-online.html, including one of the http://gishbar.blogspot.com/2010/01/lpsc-2010-stability-of-ios-paterae.html and http://gishbar.blogspot.com/2010/02/lpsc-2010-modeling-volcanic-plume-of.html, examined http://www.gishbartimes.org/2010/01/its-not-easy-being-green-chaac-patera.html, the http://www.gishbartimes.org/2010/01/science-discovery-of-ios-induced.html, and http://www.gishbartimes.org/2010/02/animation-of-jupiter-europa-orbiters.html.

Posted by: nprev Feb 23 2010, 07:50 PM

REALLY spectacular animation, Jason!

Posted by: volcanopele Jul 27 2010, 06:17 AM

I've started a new series on my blog where I profile one of Io's volcanoes each week, like I've previously done on a one-off basis for http://www.gishbartimes.org/2008/10/curious-case-of-reiden-patera.html, http://www.gishbartimes.org/2010/01/its-not-easy-being-green-chaac-patera.html, and http://www.gishbartimes.org/2010/03/tale-of-gish-bar-patera.html.

The first volcano I am profiling is Pillan Patera, a volcano responsible for the massive dark spot seen in the reprocessed image http://www.unmannedspaceflight.com/index.php?s=&showtopic=4820&view=findpost&p=162634 posted earlier today. The first part is located at http://www.gishbartimes.org/2010/07/volcano-of-week-pillan-part-one.html . I had to break it up because I want to head to Best Buy in a few minutes to get Starcraft II, but I swear, I will get the rest of it in Part Two out tomorrow. I swear I will be productive tomorrow...

Posted by: volcanopele Jul 29 2010, 03:27 AM

http://www.gishbartimes.org/2010/07/volcano-of-week-pillan-part-two.html of my series on Pillan was posted yesterday, and I just finished up on http://www.gishbartimes.org/2010/07/io-volcano-of-week-pillan-part-three.html.

I'm picking an easier to discuss volcano next week, Zal Patera...

Posted by: nprev Jul 29 2010, 03:55 AM

Interesting articles, Jason, thanks! What a weird & wonderful little world...

Posted by: monty python Jul 29 2010, 07:31 AM

You guys put so much work into this forum. I am not worthy. Thank you.

Brian


Posted by: volcanopele Aug 4 2010, 12:20 AM

The post on Zal Patera is now online:

http://www.gishbartimes.org/2010/08/io-volcano-of-week-zal.html

Along with a commentary about how Io doesn't smell that bad...

http://www.gishbartimes.org/2010/08/volcanic-moon-of-jupiter-is-not-smelly.html

Posted by: nprev Aug 4 2010, 12:39 AM

Good stuff, VP. You might also point out that nowhere in the Solar System smells even a millionth as bad as Titan probably does... laugh.gif

Posted by: ugordan Aug 4 2010, 12:48 AM

If you're thinking about methane in particular, nope - odorless.

Io might not smell bad, but if I recall SO2 is pretty aggressive stuff to the nostrils. Stings just like large concentrations of CO2 do.

Posted by: nprev Aug 4 2010, 01:16 AM

I was actually thinking of complex organics like mercaptans (sp?) & other such nasties.

Still, Io undoubtedly has a few traces of H2S here & there...that'll definitely get your attention!

Posted by: Juramike Aug 4 2010, 02:08 AM

Here is a handy reference regarding elemental sulfur and planetary geology:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19820025583_1982025583.pdf

And of course, to keep the pure sulfur allotropes apart:
http://en.wikipedia.org/wiki/Allotropes_of_sulfur

(I've used S8 before, and it was stinky, but this may have been due to trace impurities generated during the reaction.)


In general, sulfur and thiol compounds do stink. Each has there own, uhhhh, particular characteristic aroma. The really high molecular weight ones don't volatilize. Naphthyl-thiol is stink free, but benzene thiol will stink quite nicely - enough to clear a lab.

Amines can also stink (fishy odor)

Pyridines also stink (dead seaweed odor, you get used to it, but it will cause impotence).

Acrylonitrile (a significant component on Titan) will bring tears to your eyes. It is a lachrymator.
(Yours truly evacuated a lab accidentally with the similar compound acrolein. It took me 3 hours to quit crying.)

Your best bang for your buck for smell factor comes with isocyanides and phosphines. Those are just plain vile.
They have a unique smell all to their own. It is hard to describe, but once you've smelled it, you'll respect it. Spills of those materials are enough to evacuate a building (they are also pretty toxic.)

But in general, smell is difficult to talk about on Io. Your nasal receptors detect things that have diffused to it, and absorbed onto the receptor itself (a pseudoaqueous environment). If you ever smelled Io directly, you'd be dead (no pressure). If you brought Io stuff back to Earth and put it in a lab, it would be able to react with ambient oxygen and water to generate trace compounds (such as volatile sulfides) that your nose would likely find offensive. The critical thing is that you would be need to expose Io stuff to a new aqueous and oxygen-rich environment in order to smell it.

Posted by: volcanopele Aug 4 2010, 02:26 AM

The first link is a great little publication. Actually have an original hard copy of it smile.gif

Certainly my article pertaining particularly to the compounds that were found by Moullet et al., SO2, SO, and NaCl (and we can add S2/S8 to this discussion as well, though it wasn't part of their study). And of those molecules, none smell like rotten eggs, but at worst smell like burnt matches (not the best smell, but not horrendous either). But you have a good point, in order to smell anything on Io (or Titan or Mars), you would have to bring it into an alien environment, which could produce compounds like hydrogen sulfide, which does smell quite bad.

Anyways, the main point I wanted to get across with my article was the terrible re-reporting of the space.com article, focusing more on the line about how bad Io might smell, and less about the results of the paper the space.com article was reporting on. I can understand trying to connect these findings with a broad audience, but the approach taken by space.com and others was poor. For example, why not emphasize the discovery of sodium chloride in Io's atmosphere? "Gaseous table salt found in the atmosphere of Jupiter's Moon Io"? "Jupiter's moon sulfurous with a dash of salt"?

Posted by: brellis Aug 4 2010, 03:08 AM

Is it possible for something to 'stink' at such low temperatures? Disclaimer: my freezer has occasionally emitted some god-awful emittances! huh.gif

Posted by: volcanopele Aug 19 2010, 11:18 AM

Bjorn has touched on this earlier and has his own http://www.mmedia.is/bjj/3dtest/io/index.html on it, but I thought I would try my hand at creating a true color image of Io using Galileo imagery. I go into much more detail on my blog, but basically I used the ground-based spectra of Io to determine correction factors for combining Galileo violet and green filter images to synthesize an appropriate blue filter. Bjorn used the Voyager blue filter as a guide, whereas I tried to create something that was a little closer to the violet image but using the BL1 filter on Cassini as a guide. No images of Io in that filter are available, I just used the effective wavelength as something I felt was a best-case blue filter.

I post the image here, but I have the nice, pretty charts and graphs (yes, I have finally re-learned how to properly use Excel's chart mechanic, stupid Microsoft and their ribbon instead of a menu...)

http://www.gishbartimes.org/2010/08/exposing-ios-true-colors.html


Posted by: ugordan Aug 19 2010, 05:40 PM

Nice experiment. You bring up a good point about the name of the Voyager "blue" filter, I would just point out that it's actually the "green" filter that's more orange than green, making many of the old Jupiter shots look greenish among other things.

Do you have that visible spectra in tabular form? I'd love to run that through my code to see what color it produces. I threw all your Io Galileo composites through my CIE XYZ linear interpolation code to see how it'd turn out a while back. Here's that same shot (assuming the filters sampled the discrete 665, 559 and 413 nm wavelengths):



Having the actual surface spectra might make for a more accurate interpolation, especially that knee at ~520 nm. Looks like the visible spectrum could be well approximated with two or three linear segments.

While playing around with Phoenix surface images, I found out that simple channel mixing to get average wavelength works pretty good for most cases, but just doesn't cut it for objects with strong spectral slopes (and hence strong colors) - surface, calibration chips etc. It was only once I gave up on that and interpolated the spectra through 3 (or more) filters and integrated that through the tristimulus values did I get results really close to Mark Lemmon's surface shots. One thing is that a strong red hue translates into a darkening of the blue channel in sRGB gamut which is something just not accounted for with channel mixing.

Posted by: volcanopele Aug 19 2010, 08:26 PM

Would correcting my images using your code be affected by the fact that I've already corrected for the sun's varying flux at different wavelengths? The pixel values are derived from the calibrated I/F values, with each filter being stretched to 8-bit 0 (black sky) to 255 (brightest 'valid' point in the red filter image).

The visual spectra are located at http://web.archive.org/web/20031209213618/http://jupiter.berkeley.edu/index.html . The data is under Images and Spectra, and there are tables for the leading and trailing hemisphere.

Posted by: 4th rock from the sun Aug 19 2010, 09:24 PM

Nice results. Both of your processed images are consistent, with the Ugordan version having a more natural gamma (in my subjective opinion).

Posted by: machi Aug 19 2010, 09:44 PM

Volcanopele:
I like your image. It's unbelievable clarified. Ugordan's version looks too much bright on LCD monitor of my net computer, so I must take a second look on my old CRT monitor, which has much better display.

Posted by: ugordan Aug 19 2010, 10:22 PM

QUOTE (volcanopele @ Aug 19 2010, 10:26 PM) *
Would correcting my images using your code be affected by the fact that I've already corrected for the sun's varying flux at different wavelengths?

No, in fact it assumes I/F data. It needs to be I/F if you want icy bodies turning out white in sRGB which is the way I prefer.

QUOTE
The visual spectra are located at http://web.archive.org/web/20031209213618/http://jupiter.berkeley.edu/index.html . The data is under Images and Spectra, and there are tables for the leading and trailing hemisphere.

Thanks. Here's what that gives for Io's leading hemisphere. Left is gamma correct, right is everyone's preferred look. I make no claims on accuracy or correctness of my code.

FWIW, the other 3 moons' hue looks similarly yellowish with Europa being most pale yellow (leading hemisphere at least). I would also add that since these are very low phase spectra by nature (ground obs), the colors will always look subtler than typical for spacecraft which can get much higher phase imagery. That can be seen in that Galileo mosaic as well - compare to the other, higher phase version of your composite I posted in the Galileo Imagery thread.

Posted by: volcanopele Aug 19 2010, 10:46 PM

Well, I'm willing to give any correction factors you recommend based on your calculations.

Posted by: ugordan Aug 19 2010, 11:27 PM

You prefer the contrast of a non gamma-correct display so I don't know if there's an easy way out. Take for example the color in the palette at right above. You can create that disk-averaged hue out of your composite by mixing R=0.9R+0.1B and B=0.65B+0.35G. It's completely unscientific and this does preserve grey areas as grey, but as you can see the disc as a whole will appear overly green. However, if you were to average the entire visible surface and brighten the resulting color you'd see it matches the above palette color. That's the side effect of greatly stretched contrast and color in that representation - many greatly different colors which when averaged still give a "correct" hue. There likely are other such combinations.

If you want to make it visually appear at least close to that yellow color, I think you'll have to actually change level balance at which point grey terrain will no longer remain grey, but you will retain the high contrast representation of surface features.

Posted by: PFK Aug 20 2010, 12:23 PM

QUOTE (Juramike @ Aug 4 2010, 03:08 AM) *
, but benzene thiol will stink quite nicely - enough to clear a lab.


Agreed, one of the worst - and not only is it bad, I find it comes back to haunt you. Later that day, I find any other smell, even nice ones, just manifest themselves as its reappearance. Trouble is, its quite useful for us.
Bis(trimethylsilyl)sulfide is an interesting one as its pretty volatile and smells exactly like natural gas. I know sulfur additives are put in the latter, but something about this one just gets people reporting gas leaks. "Best" one we had was when I was at Imperial and an undergraduate project student vented 10s of g up and out of the fume cupboard and the gas people got called out not only locally, but in Bayswater - which if you know your London is on the other side of Hyde Park!
Drop down the chalcogens to get the real swines though - organo selenium and tellurium stuff leaves the lab with a characteristic "presence", not helped by the fact that if the people working in it have taken it onboard then they leach it out as Me2Se etc, which makes them smell like they've just done a 24hr shift in a garlic factory laugh.gif I remember getting some byproduct of an organo selenocyanate reaction down my shirt and having to hang it on the washing line for two weeks to fumigate before I even dared hand wash it!
More pertinently, does any chemistry of the latter heavier elements manifest itself on Io or elsewhere? I seem to recall some notion that there were tellurium deposits on Venus, but I don't know whether that notion is still in fashion?
Another question that is directly relevant to what we do research-wise comes with the interaction of sulfur with nitrogen. I've worked with sulfur nitrides for decades (and happily still have a full compliment of fingers despite S4N4, S5N6 etc being significantly explosive) and non are naturally occuring on earth (though I'm sure some form during volcanic events etc, but they are not stable enough to end up appearing in geological samples). But I do know of a report of spectroscopic identification of the simplest one, NS, in a comet's make up. The low temperature will stabilise it no doubt, but it will be reactive and the latter fact could manifest itself in significant addition to the overall chemistry going on in low temperature sulfur/nitrogen rich environments. But I wonder if any other evidence for such species in environments such as Io has been gathered - I'd be fascinated to know.

Posted by: stevesliva Aug 20 2010, 04:11 PM

QUOTE (PFK @ Aug 20 2010, 08:23 AM) *
I remember getting some byproduct of an organo selenocyanate reaction down my shirt and having to hang it on the washing line for two weeks to fumigate before I even dared hand wash it!


This must be what my dog likes to roll in when I take her hiking.

Posted by: volcanopele Aug 25 2010, 10:44 AM

Starting late last month, I began a feature on this blog where I highlight http://www.gishbartimes.org/p/io-volcano-of-week.html. I just wanted to let you all know about the most recent two, http://www.gishbartimes.org/2010/08/io-volcano-of-week-hiiaka.html (from last week) and http://www.gishbartimes.org/2010/08/io-volcano-of-week-culann.html (from 30 minutes ago). I wanted to call your attention to the latter in particular, for processing I've done this evening of the Galileo I25 color observation of Culann Patera:



Cleaned up amazingly well. Posted a couple more versions up on the blog.

Posted by: ugordan Aug 25 2010, 03:59 PM

What do you think of the color here:

http://www.fileden.com/files/2007/9/14/1431389/25ISCULANN01_xyz.jpg

Processed as before, but instead of leaving it in gamma-correct representation, I converted it to Lab color and applied a gamma of 0.45 there. Effectively returning the contrast level to the non-gamma-correct representation, but retaining the display-correct color (and to a lesser degree saturation). Sort of a best of both worlds version. Seems to work well for these localized features, not so much for global views.

Posted by: JohnVV Aug 28 2010, 12:47 AM

without the lines from the missing data
[attachment=22398:inpaint.jpg]
gmic 25ISCULANN01.m.png 25ISCULANN01.png -inpaint_flow 100 -o inpaint.png

Posted by: lyford Aug 28 2010, 05:50 PM

These are beautiful! Why should the Hubble get all glory when it comes to pretty space pictures? This could appropriately hang next to Rothko or Motherwell in a gallery....

Posted by: volcanopele Sep 2 2010, 09:37 AM

This week's volcano of the week was Tvashtar. So much has been written about that volcanic region, so many cool eruptions have occurred there, and so many great images (<- like my avatar), that it required three rather longish posts. I hope you guys get a chance to check them out. Informative and at least my section titles are amusing (at least to me, maybe only Seinfeld fans will get some of them...):

Tvashtar http://www.gishbartimes.org/2010/08/io-volcano-of-week-tvashtar-part-one.html - http://www.gishbartimes.org/2010/08/io-volcano-of-week-tvashtar-part-two.html - http://www.gishbartimes.org/2010/09/io-volcano-of-week-tvashtar-part-three.html


Very nice Culann renditions! I am always a bit cautious with how much interpolation I do to correct missing lines. For complex scenes like Culann or the http://www.gishbartimes.org/2010/08/high-resolution-mystery-in-bulicame.html I talked about on the blog this weekend, it can often look...not right if I interpolate a data dropout more than one line thick.

Posted by: JohnVV Sep 2 2010, 08:11 PM

"cleaning" up missing data .. to clean or not to clean , that is the question...

in my opinion it depends on what one is going to do with the data
for a scientific paper -- none .( or single missing lines )
or to impress the general public ( just look at the mer raw pan cam to the very nicely cleaned up and colorized - in a different thread )
data vs WOW factor

"it can often looking...not right"
it is very easy to do a bad inpainting job
and there is the time VS quality factor, often it will take way more time that it is worth .

Posted by: Littlebit May 17 2011, 02:28 AM

...Just a quick note to thank Volcanopele for the rich article in Emily's blog.

First class, Jason

Posted by: PFK Jul 28 2011, 04:46 PM

Little hands on experiment today to show the colour of quenched sulfur vapour (it's the central tube, right in the middle of the pic that's key here); so this is carefully dried sulfur (which is wetter than you'd think when it comes out of the bottle) flash heated under vacuum onto a liquid nitrogen cooled finger. The red/orange colour will presumably be indicative of a mix of S3, S4 and others - and comparisons with the pictures of Io's surface posted above are interesting re the colour. Note also a blue/violet tinge higher up...maybe indicative of S2? Certainly it's supposed to be that colour in the gas phase...
Apologies for the poor focus, but it's taken through two layers of glass, the outermost of which was rather warm!


Posted by: JohnVV Jul 28 2011, 06:19 PM

nice pic but a small problem ( or very big if one has worked in the photographic darkrooms since 1985)
the over head florescent light - it is yellow-green and is missing some of the daylight spectra
-- look at the back wall , it is yellow / green --
a closer white balanced might be this
[attachment=24999:sulfvapo...ebalance.png]

there is still too much yellow but seeing as the blue is missing from the over head florescent light , not much more can be done
there is a reflection on the test tube of a window - it is close to #CCCCCC just a bit off

PS. yes it is a bad habit and a side affect of the trade
I can NOT look at peoples photos and NOT see what is wrong in the photoprocessing

and do not even get me started on the "family album "

Posted by: PFK Jul 28 2011, 08:04 PM

Wish I hadn't bothered now rolleyes.gif laugh.gif
Seriously though it was but an exercise in curiosity rather than accuracy - just finished writing the sulfur chapter for the new edition of Comprehensive Inorganic Chemistry and so was intrigued to see if you could trap these out and visualise them. Obviously plenty of people in the research area will have seen them during matrix studies, but it's not obvious that they've actually shown colour images (even approximate ones) before, though I'll happily (really!) be proved wrong.
If the EPSRC want to fund me to accurately capture simulated planetary surfaces they're more than welcome, but it'll cost them a years PDRA and the dreaded Full Economic Costing smile.gif
Anyhow, the colour will be a function of precise temperature and so rather than the blunt force of liquid nitrogen we'd have to more subtely match the surface temperature of Io or wherever. Do-able, but not as a cheap and cheerful exercise over a lunch break.
Interestingly in writing about the element, the role of such smaller allotropes in planetary science came to the fore even though it's light years away from my expertise. To a large extent this reflects the fact that it's been a vibrant area (and in the context of sorting out the structure of S4) over the last decade - which is good because anyone updating the story of sulfur comes up with the difficult task of funding stuff not covered in Steudel's astonishingly thorough 2 volume effort from 2003 (recommended for anyone who needs to know about the element in detail).

PS Added in edit: we can actually get an idea of true colour by looking at the vacuum tubing on the left. This is well known to anyone in a lab - and in truth is somewhere in between the two versions. That said. to the naked eye the quenched sample did actually even more red than the photo suggests - really quite striking when it appeared.

Posted by: climber Jul 31 2011, 12:36 PM

On last issue of "Ciel & Espace" there is an interview of Irina Golodnikova called "At least, a map of IO".
Done by the ICA, I've found the link pointing to the a .PDF version of what she's talking about: http://icaci.org/documents/ICC_proceedings/ICC2009/html/nonref/26_4.pdf

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