wpo - Saturn & Jupiter's methane bands
1999 Oct 25: These mid resolution spectra via the low-res 150 l/mm grating
plus 9 micron pixels yield a dispersion of 4A/pixel [0.4nm/pixel] but are
'compressed' in this image. They show Saturn's methane bands [underscored
in blue] extending from the visible spectrum [upper half] into the near
IR [lower half] but absent from the ring system. Some of these features
may be due of other molecules like ammonia. Some Fraunhofer lettered lines
of reflected sunlight are marked and these cross both disk and ring system.
The lowest section shows Saturn to full 4A/pixel dispersion in the near
IR and includes the disk of Jupiter - the absorption bands from both planetary
atmospheres is essentially identical. The spectrum of Vega has been overlaid
on Saturn - common lines are due to the oxygen and H2O in the
earth's atmosphere.
return to main spectrometer page...
