Major planets.

A primary direction of planetary research in Kazakstan for many years has been the study of the outer planets, especially Jupiter and Saturn. Major efforts were applied to the photometric and spectroscopic observations of these planets. Scientific objectives were focused on the study of atmospheric structure and peculiarities in the vertical and horizontal distribution of cloud particles within the visible cloud cover of both planets. For this study one of the most effective techniques is the measurement of molecular absorption band intensity in different parts of the planetary disk, as well as their variations from the disk center to the limbs. The behavior of molecular absorption bands and lines in the spectra of planets surrounded by cloudy atmospheres is not trivial, and its study can yield much interesting information on the structure of the cloud layers. This is evidenced by the importance of absorption band imaging in most planetary space missions). An important role in the formation of the absorptions is played by multiple scattering (and absorption) of the light within the clouds. The intensity of the absorption bands depends strongly on the scattering properties of the cloud particles: their sizes, real and imaginary refractive indices, and number density.

In the analysis of the complex observational data about the distribution of molecular absorption on Jupiter and Saturn using a two-layer model, some conclusions have been derived about the latitudinal differences of the atmospheric structure. An important result of the interpretation of the observations, with full consideration of multiple scattering affects, was the estimate of carbon abundance. Calculations showed that both planets have an excess of carbon in comparison with solar abundance.

A new step in the study of the planets was begun in 1995 through a special grant from the South European Observatory that made possible the purchase of an ST-6V CCD camera manufactured by Santa Barbara Instrument Group. With this camera, observations were made of the detailed zonal spectrophotometry of Jupiter and Saturn yielding complete maps of their methane absorption distribution. An interesting finding was that on Jupiter the moderate and strong methane bands have clearly expressed zonal character, but weaker bands formed in the deeper atmospheric layers show more chaotic variations.

GIF 25.8K

GIF 28.3K

CCD- images of Jupiter,recorded in UV (left) and IR (right) in August 1997 with 1-meter telescope of Assy observatory.

Color CCD-images of Jupiter, synthesed from R,G,B images, recorded 6.09.1998 with 1-m telescope (21:04 UT and 21:22 UT)

GIF 17.8K

CCD-image of Saturn, recorded 19 September 1995 with 1-meter telescope

GIF 27.1K

CCD-images of Saturn, recorded through different filters in 1997

Color CCD-image of Saturn (6 September 1998, 1-meter telescope)