Changing its spots.

Jupiter is growing a second red spot, now about half the size of the famous one and almost exactly the same color.

Oval BA first appeared in the year 2000 when three smaller spots collided and merged. Using Hubble and other telescopes, astronomers watched with great interest. A similar merger that happened centuries ago may have created the original Great Red Spot, a storm twice as wide as our planet and at least 300 years old.

Oval BA has been changing colors in recent months. It was white in November 2005, slowly turned brown in December and then red a few weeks ago. Curiously, no one knows precisely why the Great Red Spot itself is red. A favorite idea is that the storm dredges material from deep beneath Jupiter's cloudtops and lifts it to high altitudes where solar ultraviolet radiation--via some unknown chemical reaction—produces the familiar brick color.

Update: National Geographic has a picture.