Wednesday, December 22, 2004

Figuring out what Titan's about

On Christmas Eve, the Cassini spacecraft, which is orbiting Saturn, will release a small probe, called Huygens, which will drop to the surface of Titan on January 14. As long as Cassini can hear Huygens' signals properly, the probe should give a lot of information about the composition of the atmosphere and hopefully even a few pictures of the surface.
The communications link is much harder than it needed to be, thanks to miscommunication between NASA planners and the Italian space agency which built Cassini's receiver for Huygens' transmissions. Basically the Italian team only halfway took account of the Doppler shifting of the communcations which will occur as the probe and spacecraft move relative to one another. Had this problem not been caught (and there have been extensive planning adjustments to just to address this one problem), most likely the communications from the probe would have been badly degraded.
This wrinkle in the mission is funny to me. My internationalist politics come in part from my experience of international scientific cooperation, both when in the US and now here overseas. But this Huygens snafu shows that even (especially?) we scientists can squabble and withhold data like anyone else. And these teams are the world's best! Luckily, they caught the problem.

Titan is really fascinating because its layers of smog seem similar to primitive earth (and present day Los Angeles). Earth-based spectroscopy has detected a lot of interesting, complex compounds, which are presumably being formed in the absence of life (it's too cold). Finding something like amino acids or riboses (the building blocks of proteins, and a chemical relative of RNA, respectively) on Titan would suggest that these compounds were also around on early Earth , meaning life here didn't have to "invent" its building blocks, but already had some raw materials.

UPDATE: For a nice summary of what Cassini has been able to see, see Planetary.org .
UPDATE#2: The ESA has a nice description of the Huygens mission. There are lots of unknowns and expediencies....

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