Last Friday, Hurricane Georges was photographed from space entering the Gulf of Mexico. This immense storm system, larger than most states, is expected to make landfall today. Starting as a slight pressure difference, hurricanes grow into large spiraling storm systems of low pressure, complete with high winds and driving rain.

La Niña is a temporary climate change caused by unusually cold water in the central Pacific Ocean. Cold water topping an unusually low sea level is shown as purple in the above false-color picture taken by the orbiting TOPEX/Poseidon satellite in mid-January.

Today's weather on Neptune will be typical. Highs in the upper atmosphere will be about -150 Centigrade, with winds ranging about 900 miles per hour near the equator. Much was learned recently about Neptune's weather by the release last week of time-lapse pictures of the most distant gas giant in our Solar System.