ABOUT THE LITTLE RED SPOT: The Little Red Spot on Jupiter is an anti-cyclonic storm formed by the merger of three separate storms observed since the 1930s. In 1998 two of the storms came together and were joined in 2000 by a third to form a storm roughly the size of the planet Earth. Using data from recent telescope and spacecraft observations, scientists determined that the storm has some of the highest wind speeds ever detected on any planet. In 2005 it started turning red for unknown reasons, and now it looks similar to its larger, more famous neighbor, the Great Red Spot. The peak wind speed for the Little Red Spot is in excess of 384 miles per hour.
WHAT IS AN ANTI-CYCLONE? Unlike hurricanes, which rotate around a center of low pressure, anti-cyclones rotate around centers of high pressure. On earth that means that air at lower elevations is forced away from the center, creating an opening that pulls cold air down from above. That leads to low humidity and few clouds. On Earth, anticyclones are often predictors of fair weather, though special conditions can create anti-cyclonic tornadoes. There are examples of anti-cyclonic storms on other planets, such as Jupiter, Saturn, and Neptune.
The American Astronomical Society contributed to the information contained in the TV portion of this report.