Friday, 1 February 2013

34000 ft Somewhere over Greenland

Rainy, dark Oxford at six in the morning in February.  The word ‘bleak’ springs to mind, as I hurry for the Heathrow airport bus.  Rain thundering against the windows as we hurtle down the M40.  But not to worry, as I’m lucky enough to be heading to the Big Island of Hawaii to spend a week observing from the summit of Mauna Kea.  I’ll be using a high resolution spectrometer called TEXES, mounted on NASA’s Infrared Telescope facility, to probe the atmospheres of Jupiter and Saturn in the thermal-infrared.  The idea is to move far beyond the photometric imaging or low resolution spectroscopy that I’m used to, to a regime where the individual spectral lines can be resolved and used to probe regions of these atmospheres that are typically hidden from our view.  This is all a bit of an experiment, so I’ve decided to share these experiences with you, oh-lucky-reader-whoever-you-are (if, indeed, anyone ever does read this!).  So be prepared for an onslaught of blog posts (if sleep deprivation and altitude sickness don’t torpedo my attempts).

It’s the start of February 2013, and it’s been five years since my last trip to Hawaii.  Several factors have kept me away – family life, the increasing simplicity of operating instruments remotely, and the use of telescopes in even more remote climes, such as the high deserts of Chile.  Last time was a single half-night of Jupiter observations from the Japanese Subaru telescope in early 2008.  I’d only just moved out to Pasadena to take up my NASA postdoctoral fellowship at JPL, and my boss Glenn Orton wanted me to join him on an observing run.

It’s far easier to visit Hawaii from LA, as the trip from Oxford involves 30 minutes to reach Oxford bus station, 90 minutes on a coach to Heathrow, two hours in the airport, twelve hours crossing the Atlantic and mainland USA, three hours exploring the wonders of LAX, then six hours out over the Pacific ocean to land in a wet and rainy Hilo on the Big Island.  This time, however, we have a whole slew of nights with the TEXES instrument, so it’s worth my while to make the trip.  I’ve never used this instrument directly before, so it’ll be a steep learning curve for me (particularly for my O2-deprived brain at 14000 ft), but I’ll have the expert, Tommy Greathouse from the Southwest Research Institute in Texas, there to guide me.  We’re all hoping for clear skies and good conditions, and plenty of data to write papers on for the next few years!

This run is really important to those of us specialising in thermal imaging of planetary atmospheres.  The thermal-IR is the best way to unravel the effects of temperature, composition and clouds in a planetary atmosphere, providing insights into their meteorology, seasonal phenomena, and bulk compositions.  With the exception of the Cassini/CIRS experiment orbiting Saturn, we have no other way to study these topics other than ground-based telescopes.  For a multitude of reasons, there are very few thermal infrared instruments working right now (instruments on the VLT and IRTF are having problems, and Gemini is no longer offering its two mid-infrared instruments).  So these TEXES observations might be our only shot at thermal imaging of Jupiter and Saturn in the next few months, to capture the events currently unfolding in their dynamic atmospheres.  More than enough reason for me to suffer the long trip halfway around our planet.  Now I’ll shut up and watch an inflight movie.....

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