The cryovolcanoes of Titan

Cryovolcanism isn't exactly a term that trips off the tongue, but evidence collected by NASA's Cassini Saturn probe suggests it may be taking place on Saturn's moon, Titan, regarded by many astronomers as very similar to primordial Earth in terms of climate.

Cryolvolanoes work off the same processes as normal volcanoes but instead of molten rock, they ooze a sludge made of water ice, ammonia and methane. Some scientists speculate these flows of frozen lava could be 200m thick.

Titan is one of the most enigmatic bodies in the solar system. The constant cloud cover obscuring its surface has long been thought a possible haven for microbial life beyond Earth, although the seething atmosphere has proved a difficult barrier to get past.

Recently though, a combination of Cassini's radar and the atmosphere itself has, potentially, led to a fascinating discovery. Scientists point to two areas where the brightness of the clouds increased dramatically as evidence of cryovolcanism. Cassini's radar even detected lobe-like features at those two locations, the expected shape of cryovolcanic flows. To cap it off, there appears to evidence of ammonia frost at one site, an element that most scientists did not expect to find on the surface of the world. It's presence is viewed by some as evidence that ammonia is being brought to the surface by cryovolcanism.

Whether or not it turns out to be true, it's clear that Titan, long beloved of science fiction authors like Kurt Vonnegut, James P Hogan and Stephen Baxter, has plenty of secrets hidden beneath its cloud cover. Whether any of those secrets involve giant hyper intelligent beetles remains to be seen…

This article contributed by Alasdair Stuart, of Hub magazine ( www.hub-mag.co.uk ).