NASA K-12 Internet: LFS Online-- K Fragment Info

This is a series of four images of the K fragment in the 7.7 micron methane region at a resolution of 9000 using KEGS on the Kuiper Airborne Observatory. In each image, wavelength increases from 7.685 to 7.722 microns from left to right. The y axis represents a long-slit spatial cut through Jupiter. From top to bottom, these images were taken at UT= 10:28, 10:39, 10:53, and 11:04. The fireball is clearly evident in the second image; the methane emission increased by about a factor of 25 compared to the pre-impact emission (top image).

The spatial scale is 4"/pixel. Our point spread function is ~7" due to motion of the airborne telescope. The brightness contours range from 1 to 43 arbitrary units in steps of 2.

The 7.7 micron region is a sensitive thermometer of the jovian stratosphere sounding levels between 1 microbar and 10 millibars, far above the visible clouds. This region is totally blocked by methane in the Earth's atmosphere -it cannot be observed from ground-based telescopes. The KAO is the only observatory capable of investigating this spectral region.

The high spectral resolution of the KEGS instrument reveals individual emission lines of C-12 and C-13 CH4. At least 2 unknown emission lines were observed in the spectrum of the fireball. These may be due to high excitation states of CH4 or due to a different species altogether.