Blue Skies on Saturn

End of story? Not quite.

"There are some things we don't understand," says West. For example, while Saturn's northern hemisphere has blue skies, Saturn's southern hemisphere does not. The south looks yellow. It could be that southern skies on Saturn are simply cloudier, yellow clouds making yellow skies.

Saturn, photographed by of Alexandria, VA, on Jan. 29, 2005, using an 8-inch telescope. Saturn's blue north is hidden behind the planet's rings.

The mystery, says West, isn't why the south is cloudy--that's normal. It's why the north is clear. "For some [unknown] reason, Saturn's northern clouds have sunk deeper into the planet, leaving clear blue air behind."

Saturn's north is so blue that West believes amateur astronomers could see the hue from Earth. Unfortunately, the north of Saturn is hidden at the moment behind Saturn's rings, a situation that will persist for another year or so.

For now, Cassini is in the best position to investigate. Will Saturn's blue skies fade? Or grow to envelop the whole planet? No one knows. It is an alien world, after all.

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