Human Journey

Another Flyby! This Time It’s Saturn’s Moon Enceladus

Even as sharp new pictures continue to flow in from the recent MESSENGER flyby past Mercury, the folks over at the Cassini-Hyugens program are conducing their own close encounter with Saturn‘s icy moon Enceladus.

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—Image courtesy NASA/JPL/Space Science Institute

This afternoon the Cassini spacecraft made its closest approach yet to the wrinkly-faced moon—a trip that brought it a mere 16 miles (25 kilometers) above the surface.

The flightpath sent Cassini deep into a huge geyser-like plume of ice and gases that has been tempting scientists since it was first spotted in 2005 with the idea that ingredients for life could exist on the Saturnian moon.

enceladus-flyby.jpg

About 20 minutes after buzzing the surface, the craft was meant to turn around as it fled the scene to capture a multispectral mosaic of the south pole.

But according to the Cassini team, the main focus of the flyby isn’t the pictures, it’s the trip through the geyser’s plume, during which time the craft should have collected samples of gas and particles for analysis.

Another flyby planned for October 31 won’t get quite as close but will come in with cameras blazing, snapping shots of the odd formations dubbed tiger stripes that are thought to be the source of Enceladus’s geyser.

Image courtesy NASA/JPL—

Understanding how the geyser operates and what it’s made of could be key to figuring out whether we’ve got as good a chance of finding life on Enceladus as on Mars.

For now, any such searches are limited by the assumption that to find aliens we have to look for what we know. Life as we know it needs liquid water (and thus a certain temperature range), organic molecules, and some kind of energy source.

Enceladus shows promise, especially when we consider all the extremophiles that we’ve found on Earth, from microbes that live without oxygen to bacteria that thrive on radioactivity, that could very well be models for what we’d find on the distant moon.

But for all we know, our various robotic or someday even human missions into space could accidentally turn up life, Jim, but not as we know it.

Would we recognize such life if we saw it, or would we plow right through it in our zeal to find something familiar, ramping up intergalactic species extinctions without pausing for a sip of Tang?

Within the very serious field of astrobiology, there are people who are dedicated to parsing out what kinds of forms “weird” life might take.

And last summer, the National Academies released a report highlighting the need to fund this kind of research, saying “it is clear that nothing would be more tragic in the American exploration of space than to encounter alien life without recognizing it.”

I wonder if these people also had something to do with Spore?

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