OFJ Field Journal from Glenn Orton - 11/29/95
ON THE EVE OF THE GREAT ADVENTUREI worked a bit more with the images, and Jose Luis - now back from the IRTF - did some work on image reconstruction: trying to recover what the image would have looked like in the absence of atmospheric blurring (called "seeing"). I can make the features line up near the Probe entry site if they all move along with a speed of 103 - 115 meters per second (222 - 248 mph-- that's relative to the deeper layers of the atmosphere). Projecting this forward to Dec. 7, I get the sense that the Probe will enter just south of a large clear area in the atmosphere where thermal (heat) radiation just beams out at a wavelength of 5 microns (a pretty clear area in Jupiter's spectrum): they are called 5-micron hot spots. But there is still some uncertainty about this "Jovian weather report."
I worked with Bob Carlson, the Galileo Near-Infrared Mapping Spectrometer (NIMS) Principal Investigator, Padma, Terry and Jose Luis to coordinate what we might do from JPL's own observatory at Table Mountain in the mountains to the northeast of JPL. They'll go up to Table Mountain Observatory (TMO, for short) on Thursday to see what could work. We have the plans all set for the observing run at the IRTF, with the major uncertainty being whether the near- infrared camera, NSFCAM, which is very sensitive at 5 microns will do worse than MIRAC (for Middle InfraRed Array Camera) at the same wavelength. MIRAC is less sensitive and produces smaller images, not letting us resolve much less than 1000 km on Jupiter. However, it is easier not to overexpose - one of our major problems with the sensitive NSFCAM. Jay Goguen from JPL and John Spencer from Lowell Observatory want to observe Io to support the particle and field experiments which will be operating through the Io flyby to characterize the status of Io's volcanoes which might or might not be erupting. That's a big IF, but Jay and John want 3 40-minute observing sessions out of our total observing allocation of 6 hours, verging on 1/3 of the available time; I was unhappy about that, thinking that 30 min would be much better. We may compromise at 35 min, but I'm still a bit distressed.
There are more ground-based Jupiter observations in the works. Dave Crisp will go up to Mount Wilson on Friday and be shown the horizontal Snow solar telescope, not being used much lately, to see whether that would work well with a JPL visual/near-infrared camera. In the meantime, our colleague Sanjay Limaye at the University of Wisconsin is at the Swedish Solar telescope at La Palma starting to churn out Jupiter images as soon as their weather turns better. I also find that Pic-du-Midi Observatory in the French Pyrenees has a World Wide Web site showing some really quite remarkable images, given that Jupiter is so close to the sun!
Then the usual things rose up, the swarm of little things that are making life busy - get the forms filled for a student part-time worker, see if the latest model comparisons with the Net Flux Radiometer team are coming together right, seeing that the models for laboratory experiments modeling absorption between hydrogen (the dominant gas in Jupiter's atmosphere) and ammonia (the horrible smelling window cleaning chemical, and a major absorber of radiation in Jupiter's atmosphere) are being fit correctly. Added to this, the fact that my wife is away: get the kids to a piano lesson (it's MY turn THIS week!) at 4:30 and then grab some great American McDonald's food - :( - and run to a barber's appointment by 6:45 through rush hour traffic, get my son to FINISH the book report due, my daughter to remember how to spell "harvest" and "family" for Friday's spelling test, get him awake on Wednesday morning and out to a special early morning class at 7:15 AM (!), then pick him up with enough time to finish homework and go to a Cub Scout meeting tonight. Linda came home by 8 PM ! (Yay!) Now she can whip out those peanut-butter-and-jelly sandwiches by 8 AM... Tell her about the arrangements and requirements for the next 7 days, give the kids 7 kisses and hugs before they're in bed (I'll have left for an early morning plane by the time they wake up!). Now finish this journal, pack Christmas cards to fill out on the airplane, see whether Terry Martin really would like to go out on the next observing run (Jan. 1 - 3, missing the New Years Holiday), and answer a mailing I got from Al Seiff - the Principal Investigator for the Galileo Probe Atmospheric Structure Experiment (which will measure pressures and temperatures and gravity as the Probe descends in the atmosphere).
Oh, and I quell my disappointment at a FAX I received from Nigel Henbest of the UK, Pioneer Productions, making a documentary for the U.S. Cable Channel "Discovery" on the events surrounding the Shoemaker-Levy 9 collision with Jupiter. They filmed me for 2 or more hours in August in my office, but their message was essentially that I was left on the editing room floor because of time constraints. Well, that's show biz!. :)