Saturn’s Hexagonal North Pole: What is Causing It?

Infrared observations of the north pole of Saturn as taken by the Cassini mission in 2007 and 2008 (NASA)

The mystery of Saturn’s hexagonal shape embedded in its violent north polar cyclone just became more intriguing.

NASA’s Cassini probe has been orbiting the ringed gas giant for four years and has just returned some of the most detailed images of the planet’s stormy atmosphere to date. The south pole has been mapped and the north polar region has been imaged in near-infrared wavelengths. The north pole is currently facing away from the Sun, so by observing the atmosphere in these wavelengths, Cassini scientists can see Saturn’s cloud formations silhouette against the background glow of the gas giant’s internal heat. This provides the perfect opportunity to see the hexagon in unprecedented detail.

So what is generating this mysterious six-sided shape?
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Carnival of Space Week 73 – Alice’s Astro Info

Image from Alice's Astro Info website
Image from Alice's Astro Info website

This week’s marvellous Carnival of Space is being hosted by Seattle-based astronomer Alice Enevoldsen at Alice’s Astro Info. To celebrate 50 years of NASA, Alice has written a rather creative CoS, using the letters from HAPPY BIRTHDAY TO YOU DEAR NASA! to form an acrostic for each submission from the space blogosphere. I love it!

From Astroengine, I decided to submit my article about the experimental evidence that radioactive decay rates do not vary with distance from the Sun, according to the power output from Cassini’s RTGs as the craft travelled from Earth to the orbit of Mars. Kinda puts a dampener on the previous terrestrial findings that decay rates may vary with distance from the Sun. Perhaps there’s another, more obvious reason for the correlated decay rate variations. I have my theory, but I’ll leave that for another day…

Using Cassini to Test Radioactive Decay Rate Variation

Artist impression of Cassini orbiting Saturn (NASA)
Artist impression of Cassini orbiting Saturn (NASA)

In a previous Astroengine article, I explored the possibility that the variation in radioactive decay rates may be synchronised with Earth’s orbital variations in distance from the Sun. Naturally, this would be a huge discovery, possibly questioning the fundamental law that nuclear decay rates are constant, no matter where the material is in the Universe. One of the conclusions in the original decay rate research suggested that we should attach a sample of a radioisotope onto an interplanetary mission far beyond the orbit of Earth. By doing this, the relationship between decay rates and distance from the Sun should become obvious, and terrestrial decay rate variations can be tested.

But wait a minute, let’s have a think about this. Haven’t we already sent radioactive material on board interplanetary missions? What about all that plutonium we use to power interplanetary probes like Voyager, Pioneer, Galileo or Cassini? Plutonium is pretty radioactive… isn’t it?
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