Saturn’s Moon Titan Has Gone Cold

Saturn’s Moon Titan Has Gone Cold: "
Space exploration is a fickle thing. From Earth Saturn’s moon Titan appears to be a cold and lifeless ball. From the Voyager spacecraft she appeared to have an atmosphere. From the Huygens probe, which actually landed on the surface, we learned that the atmosphere is a nasty mix of methane and hydrocarbons. Huygens also brought us the intriguing possibility that Titan is volcanically active.

Volcanism on Titan could be triggered as it is on Earth, by the inward pressure of its mantle on its rocky core coupled with the gravitational pull of other bodies, in our case the moon. Titan is so far from the sun, however, that volcanoes there would most likely be shooting water instead of molten rock.


The presence of volcanism, when linked with the thick atmosphere and the evidence of rain, oceans, and lakes, made Titan appear almost Earthlike. Cold, yes, but with that internal heat source perhaps a potential birthplace for life. Perhaps.

New data returned from the Cassini spacecraft visiting the Saturn system, however, has sadly shut down Titan’s volcanoes. No internal heating, no geothermal activity. No crucible for life on the shores of a methane lake. Cold, hard rock in the center.

Scientists released their findings in the April edition of the science journal Icarus. The surface features that once looked like volcanoes, they say, are most likely formed by the fall of methane rain from that thick atmosphere. The thick clouds create a greenhouse effect, trapping what little sunlight hits the moon and keeping the lower levels of the atmosphere warm enough for the methane to fall in liquid form and puddle on the cold, dark surface.

In fact, scientists believe that Titan may have more in common with cold, silent, ancient Callisto. That moon, having no geothermal forces inside, bears one of the oldest faces in the solar system. Like our moon, there has been nothing to alter Callisto’s face beyond the impact of meteorites.

Space exploration is fickle. Hopes that are raised about Titan being Earthlike are quickly dashed by the same probe that raised them. Still, it’s nice to know more about Titan and her thick atmosphere.

Titan’s demotion to a cold, silent ball of rock should remind us just how unique our home is – there’s nothing even close to it in the entire solar system.

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