OFJ Field Journal from Glenn Orton - 10/13/95
DOING THE VARIED WORK CALLED SCIENCEThis week I've been attending the annual meeting of the American Astronomical Society's Division for Planetary Science, preceded by a week of vacation which took place (quite coincidentally) less than a couple of miles south along the Kohala (northwest) coast of the big island of Hawaii. This is the annual meeting which is the most important for me, as I get to interact with a large number of colleagues in similar directions of work. I also get to hear some of "the latest" and most important news from other fields in review sessions.
The vacation was nice and relaxing (well, as relaxing as it gets with squabbling 7 and 9 year olds), and it occasionally gave me a sense of cognitive dissonance. I could see the summit of Mauna Kea (where I usually observe Jupiter etc.) from the back balcony of the condo. I could see Jupiter and the moon, as well. My brain said, "I know where I am - I've been here before", but then the palm trees swayed and I heard the ocean and realized that I wasn't at the summit but down at 1 atmosphere pressure, and I'm supposed to be enjoying myself and not thinking about planets except in science fiction.
Still, I knew that Hubble Space Telescope was taking images of Jupiter, and with that the knowledge that the NASA Infrared Telescope Facility was working on an automatic program which would image Jupiter and its innermost Galilean satellite, Io, whenever its facility near-infrared camera (operating at wavelengths between 1 and 5 microns) was being used. How were the images? For a while, I didn't have any electronic access to the data, although - unlike being at home in Arcadia, California (one town east of JPL's home of Pasadena) - at least I knew what the weather at the summit was.
I had spent the month before the meeting frantically getting graphical and photographic results out from a half year of observing Jupiter in a really intensive Galileo-supporting program. This was generally done between 9 PM and 3 AM, while my day job centered on serving on Jury Duty in the Los Angeles County Superior Court system, finally ending up as a juror for someone who was fighting his conservatorship by the Veterans Administration Hospital psychiatric lock-up ward - and in that rewarding experience, we ended up with a hung jury. While I was to be on vacation, proposals for renewing time on JPL's Cray supercomputer were due, as were proposals for telescope time at Palomar and at the NASA IRTF; of course, I had to get THOSE all done before I left, too.
So the long-anticipated vacation (it had been delayed a year as a result of my wife's hospitalization) was REALLY appreciated. Yet it was hard to turn off my brain. At least I got to show my mother, who went along with us, the summit of Mauna Kea and the 10 or so telescopes operating or under construction up there. She didn't have a problem with the altitude (nearly 14,000 feet and only about 63% of sea level pressure). About a decade ago, I brought my wife, Dr. Linda Brown, a spectroscopist at JPL, to the summit where she succumbed immediately to altitude sickness and swore that she'd never return EVER!
I had a Sun workstation at the DPS which I'd requested as a way to show the results of the NSFCAM program to a meeting of the International Jupiter Watch Atmospheres Team: these are professionals who are interested in examining the time-dependent variability of physical and chemical conditions in Jupiter's atmosphere. (I should note that some dedicated amateurs ARE on the electronic mailing list: if you want to be on it, contact me at email@example.com). I found out, then, that the NSFCAM images supporting the shorter-wavlength HST observations were pretty good. I also had two colleagues, (Dr.) Jim Friedson and Joe Spitale, who were at the IRTF from Wed. through Fri. nights (Oct. 11 - 13). Jim is a research scientist, as I am; Joe is a recently graduated Caltech student taking a one-year hiatus before returning to graduate school in planetary science. He had worked for me as an undergraduate student starting in the spring of 1994, and he developed a menu-driven program for efficient reduction of our astronomical data, particularly infrared imaging. It goes by the unattractive name of DRM, for Data Reduction Manager.
Jim and Joe were using NSFCAM over an extended set of wavelengths than the automated program (which only records 5), and they were working with MIRAC2 - the Middle-Infrared Array Camera, Version 2 - one of the first of a new generation of 128 x 128 array cameras working between 5 and 25 microns. This region is one in which I'm particularly interested, as it gives us direct information on the temperature structure of the planet in both the stratosphere and the troposphere. This, in turn, is our primary clue to what is driving the circulation system. Before last summer, we'd been more routinely mapping Jupiter's temperature field by using a single-element detector, a facility instrument on the IRTF which was available to anyone, and literally scanning in a regular pattern ("raster scanning") over the planet in somewhere between 20 to 50 minutes. This was effective, as it gave us a chance to see a great deal on the planet, and we published two major articles in the well-known scientific journal Science which is particularly choosy about the types of articles that it will print. On the other hand Jupiter rotates significantly in this time (it has a 10-hour period), forcing us to make odd corrections for constant longitude lines which were being swept around the planet as we took the data. Finally for the Shoemaker-Levy 9 Comet Crash campaign at the IRTF, MIRAC2 was commissioned for the first time and worked almost without flaw, allowing us to do in a minute or two what took a major fraction of an hour with raster scanning, as Jupiter fit entirely inside its field of view.
On Oct. 11, Jim and Joe got a very short briefing from another astronomer on MIRAC2's current method for operation, and they got some standard star data and just a little bit on Jupiter before it set in the west. The following night, they got a little bit of NSFCAM data at the same longitude as the Galileo SSI experiment (a CCD camera) in the later afternoon before doing a little bit more on MIRAC2. On the final night, MIRAC2 had not been cooled with liquid helium properly by the IRTF day crew and it was warm and unusable, so only NSFCAM data were obtained. On the other hand, the seeing that night (the "jitter" of the atmosphere) was quite low, and the near-infrared images were quite good.