Jupiter's Great Red Spot Is Shrinking

Jupiter's Great Red Spot may need to come up with a new moniker—not only has the spot shrunk down to its smallest measure ever, its shape is changing.

In the 1800s, the spot was measured at over 25,000 miles across. Today, that measure is at 10,250 and falling. Since 2012, Jupiter's red spot has been dropping in diameter by more than 500 miles a year. As it gets smaller and smaller, its shape is also shifting from an oval to a circle.

The great red spot—which (at least at its current size) is larger than Earth—is formed by a gigantic, anticyclonic storm. Researchers suspect slight changes in its composition are behind the decrease in size, though, as yet, it's still unexplained.

Image: NASA /ESA