Various forms of elemental sulfur might be responsible for the riot of color we see on Jupiter. Sulfur forms polymers (S₃, S₄, S₅, S₈,) that are yellow, red, and brown, but no sulfur in any form has been detected on Jupiter. “We never promised you we were going to identify the colors on Jupiter with this mission,” one of the atmospheric scientists remarked, “but we will have a probe that is going into the atmosphere in the mid-1980s—Galileo.” Perhaps the mystery of the Jovian clouds will have to wait till then. Temperature maps of Jupiter were obtained by IRIS in radiation arising at different levels above the clouds. Maps show temperatures at pressures of 0.8 atmosphere near the clouds, and 0.2 atmosphere near the top of the troposphere. In addition to the low temperatures over the bright zones and the higher temperatures over dark belts, there is a great deal of smaller scale structure. It is interesting that a cold area corresponding to the Great Red Spot is clearly visible even near the top of the troposphere, indicating that this feature disturbs the atmosphere to very high altitudes. The structure of the atmosphere of Jupiter above the troposphere was investigated through the radio occultation experiment as well as by IRIS. The level in which the minimum temperature of about -173° C occurs has a pressure of 0.1 atmosphere. Above this point lies the stratosphere, in which temperatures increase with altitude as a result of sunlight absorbed by the gas or by aerosol particles resembling smog. At 70 kilometers above the ammonia clouds, the temperature is about -113° C. Above this level, the temperature stays approximately constant, although at extreme altitudes the temperature again rises in the ionosphere. [Illustration: If one could “unwrap” Jupiter like a map, views such as these would be obtained. The comparison between the pictures shows the relative motions of features in Jupiter’s atmosphere. It can be seen, for example, that the Great Red Spot moved westward and the white ovals eastward during the time between the acquisition of these pictures. Regular plume patterns are equidistant around the northern edge of the equator, while a train of small spots moved eastward at approximately latitude 80° S. In addition to these relative motions, significant changes are evident in the recirculating flow east of the Great Red Spot, in the disturbed region west of the Great Red Spot, and as seen in the brightening of material spreading into the equatorial region from the more southerly latitudes. [P-21771C]] [Illustration: The planet as it appeared about March 1.] [Illustration: As it was in early July.] Weather on Jupiter