In addition to its famous "Great Red Spot," Jupiter had a smaller "White Spot" - which recently turned red.  "Red Spot Junior," as it has been dubbed, recently buzzed its larger sibling. This close encounter between the two Red Spots did not appear to weaken the smaller of the two, but astronomers are still keeping Hubble's eye on it. The two Red Spots were 3500 kilometers apart (less than 2200 miles) at their closest approach on July 15thThere should be a, and will completely pass one another by the end of the month.

The small White Spot  designated as Oval BA changed its color earlier this year. "We don't know why it is red," says Amy Simon-Miller, a planetary scientist at NASA's Goddard Space Flight Center. "It seems likely that the color is tied to storm strength."

Despite their proximity,  the pair is unlikely to merge, forming a "mega-storm," since Jupiter's jet streams keep each corralled into their respective latitudes. The passing could still weaken Oval BA and turn it back into a white storm, however.

Oval BA initially formed when two white ovals merged in 1998. A third one joined them in 2000. Currently, Jupiter is moving out of Hubble's range, and will not be back in position until next February.  Other instruments, including those of  amateur astronomers, continue observing the phenomenon, however.