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Observations of the stratospheric IR emission structure on Saturn are presented. The high-spatial-resolution global images show a variety of new features, including a narrow equatorial belt of enhanced emission at 7.8 micron, a prominent symmetrical north polar hotspot at all three wavelengths, and a midlatitude structure which is asymmetrically brightened at the east limb. The results confirm the polar brightening and reversal in position predicted by recent models for seasonal thermal variations of Saturn's stratosphere.

An ambitious postperihelion observational program has been carried out which significantly extends the scope of the Halley water investigation. The spectral bandwidth of the postperihelion data included essentially all of the nu3 band. Fifteen spectral lines of water were detected, including three previously undetected lines in the nu3 band and three lines in the (011-010) band. The observed relative intensities illustrate that water in the cometary coma is rotationally relaxed, as predicted by recent nonthermal equilibrium models. An ortho/para ratio of about three is consistent with both pre- and postperihelion data. The water spatial brightness profile can be fit by that of a parent molecule, and a significant sunward-tailward brightness asymmetry was observed which suggests ejection primarily into the sunlit hemisphere. Comet Halley exhibited marked temporal activity on time scales as short as two hours. The largest water production rate measured was 2.3 x 10 to the 30th mol/s on 24:18 UT in March 1986, which is about an order of magnitude or more larger than the production rates measured preperihelion at the same heliocentric distance, indicating a large pre- to postperihelion asymmetry in gas production.