Saturn's moon Enceladus may host "internal life"

Tuesday, March 13, 2007 

Plumes of icy material extend above the southern polar region of Saturn's moon Enceladus, as imaged by the Cassini spacecraft in January 2005.

Scientists at NASA say that new satellite images of Saturn's moon Enceladus taken in 2005, has shown that the moon has begun to spew geysers which contain liquid water, and that the internal heat produced by the moon's core may be able to host life below the icy surface, but scientists also stress that life has not yet been found on the moon.

Scientists say that the heat source producing the geysers is "organic" and that the material used to spew them is caused by the decaying of radioactive material from inside the moon.

"Deep inside Enceladus, our model indicates we've got an organic brew, a heat source and liquid water, all key ingredients for life. And while no one is claiming that we have found life by any means, we probably have evidence for a place that might be hospitable to life," said Dennis Matson, a scientist for the Cassini project.

In a new model created by NASA scientists, data shows that Enceladus might have been created by aluminum and iron isotopes which have begun to decay causing large amounts of heat to build up in the moon and over billions of years later, the icy mass has began to melt near the moon's core, causing the water to spew into outer space.

"Enceladus is a very small body, and it's made almost entirely of ice and rock. The puzzle is how the moon developed a warm core. The only way to achieve such high temperatures at Enceladus is through the very rapid decay of some radioactive species," said Dr. Julie Castillo, the lead scientist developing the new model at the Jet Propulsion laboratory or JPL.

"The decomposition of those isotopes - over a period of about 7 million years - would produce enormous amounts of heat. This would result in the consolidation of rocky material at the core surrounded by a shell of ice. According to the theory, the remaining, more slowly decaying radioactivity in the core could continue to warm and melt the moon's interior for billions of years, along with tidal forces from Saturn's gravitational tug," said a statement on NASA"s website.

Data from Cassini's ion and neutral mass spectrometer further shows that the natural building blocks of life are also present within Enceladus. The results show that carbon dioxide, acetylene, methane, propane and nitrogen, the basic building blocks for life, are all present within the moon.

"The team concludes that so far, all the findings and the hot start model indicate that a warm, organic-rich mixture was produced below the surface of Enceladus and might still be present today, making the moon a promising kitchen for the cooking of primordial soup," added the statement.

Cassini will make a flyby on Enceladus in march of 2008. The mission will "measure the gas emanating from the plume," ended the statement.

Sources

• Brian Jackson. "Icy moon's hot core could support life" — Discovery Reports Canada, March 13, 2007
• "A Hot Start Might Explain Geysers on Enceladus" — NASA, March 12, 2007