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Enceladus gets active

Cassini probe finds giant geyser on icy moon.

Saturn's small moon Enceladus was once thought to be too small, at just 500 kilometres across, to be geologically active. But during three flybys in 2005, NASA's Cassini probe found a series of clues that tell a very different story.

Read the story here and view the slideshow here.

Posted by Nicola Jones on March 09, 2006
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This is just fun speculation, but what if Enceladus was a one in a trillion target of a radioactive asteroid? Something produced outside the solar system perhaps. An asteroid of radioactive potassium and heavy metals could explain what's going on. Can such things exist? If it could, it might explain a few things easily. No crater would be in evidence, because the radioactivity of the debree would keep the resultant crater warm, and quickly erase it. It is odd how all the moon's activity is confined to just part of it, rather than dispersed in some pattern around the globe. The heavy metal component would help it survive the impact rather than be destroyed as an asteroid made up of material similar to the moon's. Instead it might break up into several significant chunks. Then again obliteration might be a good thing, and spread the debre over a wide area. Once the violence of the impact settled, they'd start to migrate towards the core of the moon by melting through the surface. As they sank deeper the moon's crust would provide enough insulation for the radioactive remnents erase crater evidence and to melt the subsurface as they migrated downard. This of course would takea long time, and as long as they were active they'd warm up the surrounding moon material and supply heat for the geysers. I mention potassium because it has a half-life of over a billion years. Uranium would work though since it's half-life is 703 million or so years. So if Enceladus were hit 500 million years ago, that would give far more time than needed to create what we see. OF course the asteroid need not be entirely made up of radioactive materials. It could be mostly Iron or something.

Posted by: John Morales | March 10, 2006 06:40 PM

What is presumed to be the heat source? My guess is a large concentration of radioactive material.

Also, the combination of water, CO2, CH4 suggests life sources.


Posted by: Paul | March 10, 2006 07:00 PM

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