3/11/2006: Enceladus

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Nice Saturday, nice day for a really huge IotD.
Widen your browser windows and read on.

This is Enceladus, one of Saturn's moons. It was featured yesterday on the Astronomy Picture of the Day. Why: because it's suddenly become one of the most exciting places in the solar system.

Already you look at it and you say, whoa, something must be going on here. Why is only half of it marked with craters? That's important - that means the part not marked is changing, faster than the time it takes for stuff to hit it and mark it up.

And what's up with all those blue cracks and stuff?

So they sent a craft, Cassini, to get more info. When Cassini measured the surface temperatures, they learned that most of it is, yeah, -200C, as expected; it's way far from the sun, so it's all extremely cold, like colder than Canada in winter even with "wind chill" taken into consideration. But here's the thing, those cracks are warmer than the surrounding area:


They think this is caused by "towering jets and plumes of material erupting from the moon's surface". Not all the time, but in occasional rare events, water is blasted out of those cracks at 0 degrees Celsuis. Water! Here's what they think is going on:



We have similar geysers here on Earth, such as Old Faithful:


But it turns out that we've only noticed active volcanism in two places: Earth, and Jupiter's moon Io, which spews lava and sulfur all over the place. They think volcanism is also present in a moon of Neptune.

So this would be a pretty amazing and rare thing, but aside from being a really cool phenomenon, it also means water may be more available and in different places than we previously considered. And as such, there may be more possible locations for life "as we know it" to come about. Not necessarily on Enceladus, but elsewhere in this and other solar systems.