Does a Dense Atmosphere Exist Around Io?

1. Does a Dense Atmosphere Exist Around Io? John Menke June 2014 X X X

3. Origin of Study Degenhardt papers SAS2010, 2013, etc Observed Io(F)/Europa(R) occultations (video) Observed dimming before/after occultation (wings) Interpreted as dimming from thick atmosphere (Jovian Extinction Events..JEE) My investigation was for a decision whether to take data in 2014 (I decided not to)

4. Degenhardt observations (two observations of many) Wings X X X

5. R R Occultation Eclipse Earth,F&R in perfect line R likely not in shadows F&R in line R in shadows X F F Images do NOT converge Images converge

6. Critical Problems Pro-Astronomers see no thick atmosphere Eclipses show no wings Duplicate observations show null results

7. 1 Pro-Astronomers see no thick atmosphere Telescopic searches w/big scopes and HST have never imaged atmosphere Advanced spectroscopic searches w/big scopes show only very faint (10^-9) atmospheres Note: JEE references out of context) Satellite probes near Jupiter see none Satellites within 200km of Io saw/felt none, would literally have slowed down or burned up Extended JEE atmosphere not gravitationally feasible (Menke) See Mallama paper for details #1. The Galileo Orbiter flew within a few hundred km of Io and Europa, yet spacecraft navigation experts found no atmospheric drag in the radio tracking data.#2. Images of Io and Europa taken by the Hubble Space Telescope reveal no atmospheres surrounding these satellites.#3.An examination of 50 Hubble images taken in ultraviolet, visible and infrared light when Io or Europa were transiting Jupiter show that there is no extinction due to an extended atmosphere.#4. An examination of 19 high quality PHEMU light curves, where Io or Europa occulted another satellite and in which data was taken well outside of the occultation itself, show no evidence for atmospheric extinction.#5. Decades of research conducted by world-class planetary scientists using all the available Earth-based and spacecraft data have conclusively shown that Io and Europa only possess extremely rarified exospheres whose particle densities are billions of times less than the Earth’s troposphere. s

8. 2 Eclipses show no wings, but they should Io atmosphere should cast shadow during eclipse, but not seen No explanation

9. 20090901 occult s 1000 sec 3 Duplicate observations show null results Redding (in JEE group) had null observations explained adhoc -PDE, threshold (no physics, no predictive value) Others also see no wings, eg Gerhard Dengl (one of many) [No physics basis for PDE or threshold presented] s

10. Any ONE of the foregoing problems is a fatal flaw for JEE JEE does not exist if even ONE of these is true

11. Lesser Problems Inadequate documentation Photometric methods not used (eg, ref, linearity) Why video, why not CCD observations, no confirmations from am or pro Overly defensive criticism of objections, many words, but non-rebuttal on physics

12. But if not real, what was it? Some other Jovian effect-hard to think of one Analytical (eg., software)-Lots of data, but only LiMovie used Instrumental-potential for video non-linearity Obtained video data from Degenhardt of six events X X

13. Typical video frame... Ganymede Jupiter Io/Europa Callisto Event 20090901

14. Technique:Convert video to JPGs Use VirtualDub to select ~100 frames Export/ImageSequence/..JPG Paste into Maxim or other photometry prog, examine pixels, take averages, etc.

15. Analytical problem? Test:Did I reproduce wings? VideoData LiMovie YES VideoData JPGs MaximDL YES Wings NOT an artifact of processing Test validates JPG/photometry methods Only thing left is a sensor/system problem..

16. Video non-linearity concerns Video cams not tightly specified Hidden algorithms, large/small scale features Gamma used in video Output=input ^ gamma Gamma=1 linear Gamma applied in camera and/or LiMovie Saturation and Roll-Off issues..

17. Saturation and Roll-Off issues, cont Unknown behavior approaching saturation (Roll-Off) Actual saturation – 8bit=255 limit Linearity/roll-off not measured X

18. . . . Can we tell whether system is generally linear? Test: Linearity (when no sat).. Convert to JPGs, measure ratio intensities Linear Video Dimming (wing) Yes, sensor appears roughly linear If generally linear, then how about saturation or Roll-Off?

19. What is happening in images? During occultation, images merge (During eclipse, do not merge) Saturation MUST cause light loss and, ANY saturation shows out of control X X X

20. Simulate saturation… Can saturation cause wings? Software, slide one PSF over another, measure intensity Qualitative, features only Can adjust saturation, gamma, spacing, noise, etc Saturation is plausible cause of wings X

21. Is saturation present in JEE video? Note:LiMovie poor tool for evaluating video, so used photometric methods Convert to JPGs, inspect all objects, different times, Jupiter-heavily saturated Ganymede-seldom saturated Io/Europa-increasing saturated pixels as merger/ occultation proceeds (Io+E>G) Callisto (faintest) – never saturated Yes, extensive Io/E saturation present in all JEE events (but not in Null observations)

22. Typical frame near occultation Saturation X X X Io X X

23. Is the saturation sufficient? Hard to measure or calculate – lost information. Use surrogate: Note-Io+Europa = 1.2xGanymede..use G. as surrogate Multiply Ganymede pixels by 1.2, measure intensity: gives UNsaturated equiv. of Io+Europa Apply saturation limits (tool in Maxim) Remeasure intensity.. gives SATurated equiv of Io+Europa Result—Saturation dims intensity 10-14% ~same as wings

24. One last item.. Remember - some JEE group occultation videos show NO wings (PDE, etc given as cause) But examining video data shows they were taken with longer fl scope-larger images, lower pixel values, no sat. plus, other video observers do not see wings when properly using video

25. Conclusions 3 critical problems w/JEE: astronomic data, eclipses, other observers null results, plus Saturation in video is shown sufficient to cause apparent dimming (JEE wings) Root problem-insufficient attention to sensor, and failure to use photometric methods Interpretation of data incorrect: there is no thick Io atmosphere X

26. Comments on “the debate”… Given the extraordinary claim, one must resolve, not bypass, all the major problems before taking JEE seriously One can ALWAYS make arguments and find some data to support any view, but critical thinking (and Occam) is key in evaluating Most of our debates are political debates about values: This is a scientific debate about evidence and physics. JEE is true or it is not Continued debate or investigation after a problem is solved may be a sign of bad science.