March 30, 2007—No, Jupiter hasn't acquired a new toupee and goatee to impress Venus.

Those dashing purple puffs are x-ray images of the gas giant's high-voltage auroras—"northern lights on steroids," said planetary scientist Randy Gladstone of this image released yesterday by NASA.

The colorized picture is something of a collage. Several x-ray images taken by NASA's Chandra X-Ray Observatory have been combined and superimposed on the latest Hubble Space Telescope image of Jupiter.

"Jupiter has auroras bigger than our entire planet," said Gladstone, of the independent, nonprofit Southwest Research Institute in Texas, in a statement.

Gladstone hopes these latest observations will help him crack some Jovian mysteries. For starter, what causes these "hyper-auroras"?

The solar system's biggest planet and its magnetic field rotate extremely quickly—every ten hours—generating ten million volts around its poles. Toss in charged particles from the volcanic moon Io and you've got a crackling, nonstop sky show.

But how do the volcanic particles get from a relatively small moon to Jupiter's planetary poles? That, Gladstone says, remains one of the planet's unsolved puzzles.

(Watch a brief animation of Io's particles interacting with Jupiter's magnetic field to create auroras.)

—Ted Chamberlain

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