Weather Report From Titan

owillis writes "Space.com is reporting that Titan (moon of Saturn)" (and also the setting of a classic sf trilogy) "has mountains, a sea, and rain showers." Details apparently in the latest issue of Science. Cassini will parachute a probe into its atmosphere in 2004, but unfortunately may not be able to retrieve all its data. Let's hope they figure out a fix in the next four years; Titan's on the short-list of plausible environments in our solar system that could harbor life.

Comments

Re:A bit of a routine

[tesserae]

I doubt that many (if any) genuine researchers really thought that there was any chance that the formations found on those meteorites were formed by life. I don't believe the meteorites themselves were faked but I have major doubts about the credibility of the researchers.

Believe what you will. The truth is that the researchers involved are all credible, with decent publishing histories behind them. And the initial paper was published in Science -- not exactly a journal known for accepting hoaxes, although they do like to be the first to publish controversial papers (and this was no doubt a controversial paper). But "controversial" != "hoax"... and the stature of some of the researchers involved is such that they'd be fools to perpetrate a hoax and destroy their careers.

I won't deny that NASA took advantage of the paper, but calling it a hoax is dangerously close to libeling some good researchers (only some of whom work for NASA). You might want to reconsider your statement?

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More detail on what's happened

[tesserae]

From the space.com article, discussing the newfound problem with the Cassini probe's data reception:

"The problem is in the receiver: the bandwidth within it is not as wide as the design called for," said Bob Mitchell, the Cassini program manager at NASA's Jet Propulsion Laboratory.

I don't know if that's JPLese and he's not completely describing the problem, or if space.com didn't understand it, although they hint at the cause on the second page. What happened is this:

When the receiver was designed, the Doppler shift in the probe's signal in the operational mode wasn't accounted for; it worked fine on the bench, with no delta-V, but the Doppler shift at Titan will push the sidebands (where the data is being transmitted) out of the receiver's range. Cassini will be going like the proverbial bat out of hell as it passes Titan and drops the probe, and the Doppler shift will be substantial.

Technically, this is "not as wide as the design called for," I guess, and it's not clear whether it's lack of a proper specification or lack of attention to detail (and I really can't guess which, since I never worked on that project -- I just talked this week to some of those who did).

The article also mentions slowing Cassini down for the encounter, but fails to mention that doing such a thing will screw much of the science opportunity: the subsequent gravity-whip maneuvers depend on the initial velocity and positioning, and losing that will prolong the mission, pushing much of the science past the design life of the spacecraft. Not to mention they'll have to completely recalculate the entire circum-Saturn trajectory, a task for which there's no funding.

It's a real bummer: this might be the last of the "big" planetary-science missions for a long time (everything else is "faster-better-cheaper", and we've seen some of the downsides there), and one of the most exciting parts is endangered -- so much that they're considering crippling a major fraction of the rest of the mission just to recover it.

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