United Kingdom Infrared Telescope Observing Plans for Comet Shoemaker-Levy

From John Davies

This is a draft of an article which I expect to appear in the Royal Observatories Newsletter a few weeks from now. I send it to you in case you wanted to add it to your file of general information for the public and media. Its a bit technical, but not hopelessly so.

UKIRT OBSERVATIONS OF THE 'GREAT CRASH OF 94'

The 3.8m United Kingdom Infrared Telescope has made special arrangements to observe the results of the impact of comet Shoemaker-Levy-9 with the planet Jupiter later this year. A two week period around the time of the crash, starting on July 14th, has been set aside for observations of the event and its aftermath. During this period Jupiter is an afternoon/early evening object so observing will start at 3pm and comet observations will continue until 10pm each night. The latter part of the night has been assigned to other programmes and observing for these projects will stop no later than 5am.

Three groups were awarded time to observe the comet crash and all will take advantage of the power of CGS4, UKIRT's near infrared array spectrograph. Dr S Miller and his collaborators (6 half nights) hope to observe emission from H3+ in the Jovian ionosphere. They will also search for other species which have been either dredged up from deep within Jupiter's atmosphere or produced during the chemical reactions produced by the release of energy during the impact. Dr Glenn Orton's group (6 half nights) will attempt to characterise the horizontal and vertical distribution of particles in the atmosphere and map to the distribution of neutral gases released from the comet and injected by the collision into the stratosphere from lower levels of Jupiter's atmosphere. Drs Keith Noll and Roger Knacke (2 half nights) will search for oxygen bearing molecules such as CO and H20 as the crash will probably introduce considerable amounts of oxygen into regions of Jupiter's atmosphere where this element is normally rare.

CGS4 will be configured with its long focal length camera and will have its 75l/mm and echelle gratings fitted. This will allow observations to be alternated quickly between either moderate or high resolution spectroscopy. Other instruments, including the new Infrared Camera IRCAM3, will also be available for use depending on observing circumstances and any unforeseen developments on the planet following the impacts.

In view of the uncertainties regarding the collision, the precise schedule for these observations will be as fluid as possible in order to maximise the potential scientific return. UKIRT will also be co-ordinating its programme, as far as is possible, with those of other telescopes, most notably the NASA IRTF on Mauna Kea.

John Davies JACH

THE FOLLOWING PROJECTS WERE ALLOCATED UKIRT TIME FOR OBSERVING THE COMET CRASH. OBSERVING WILL START MID AFTERNOON AND CONTINUE UNTIL JUPITER HAS SET AND CALIBRATIONS DONE. OTHER PROJECTS ARE SCHEDULED FOR THE LATTER PART OF EACH NIGHT. THE CRASH PERIOD IS DEFINED AS JULY 14-27.

PLEASE CONTACT THE PI'S FOR DETAILS, CO-ORDINATION OF PROJECTS ETC

PI: S MILLER  UNIVERITY COLLEGE, LONDON   PROJ:  SEARCH FOR H3+ AND H2 EMISSION.
CO-I: TRAFTON,OKA,JAGOD,BALLESTER,
      GEBALLE,TENNYSON

PI: G ORTON   JET PROPULSION LAB, PASADENA    PROJ: NEAR IR SPECTROSCOPY
CO-I:  BROOKE,BJORAKER,FRIEDSON

PI: K NOLL    STSCI                           PROJ: VARIATIONS OF CO AND H20
CO-I: KNACKE

Comet Shoemaker-Levy Home Page

For suggestions or additions to the this page, please contact:

Ron Baalke
ron@jpl.nasa.gov