Saturn's magic lantern
Posted: Friday, October 06, 2006 3:46 PM by Alan Boyle
Astronomers have used the faint infrared glow from Saturn's warm interior to light up the planet's deep cloud patterns from within - creating an effect they liken to a Chinese lantern.
It's just the latest cool, colorful view from the Cassini spacecraft.
NASA / JPL / Univ. of Ariz. |
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Saturn's interior glows like a Chinese lantern in this
image from the Cassini spacecraft.
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The inside-out image of Saturn was captured in February by Cassini’s Visual and Infrared Mapping Spectrometer from a vantage point directly in line with the planet’s rings. The ring plane shows up as a thin blue line running across the middle of the disk.
Views of Saturn in three infrared wavelengths were put together to create the color-coded mosaic. As described in Thursday’s image advisory, the blue-green shades at lower right result from sunlight scattered off clouds high in Saturn’s atmosphere.
The reddish colors represent the glow of thermal radiation from the planet’s warm interior, which can be made out more easily on Saturn’s night side, at left. Darker reds show the strongest thermal radiation from the clouds, and brighter reds indicate areas where the atmosphere is clearer.
“The brighter glow of the northern hemisphere versus the southern indicates that the clouds and hazes there are noticeably thinner than those in the south,” the Cassini team says. “Scientists speculate that this is a seasonal effect, and if so, it will change as the northern hemisphere enters springtime during the next few years.”
Cassini may well be around to see that: Its primary mission began in 2004 and is due to finish up in 2008, but managers at NASA, the European Space Agency and the Italian Space Agency are certain to extend the mission for years longer.
