Huygens Probe Lands on Titan

WillDraven writes "CNN, NASA and the ESA are reporting that the Huygens space probe has entered the atmosphere of Saturn's moon Titan after traveling 2.2 billion miles. Pictures from the moon's surface should be available sometime this afternoon" according to the NASA TV schedule. What we know so far is that Huygens landed successfully and sent at least the carrier signal from the surface to Cassini for 90+ minutes, more than expected, and that Cassini has successfully repointed at the Earth and begun relaying the data it received, beginning with test packets. Huygens now sits on Titan, silent forever, while we wait to see whether or how much valuable data Cassini obtained and can send back. Update: 01/14 17:20 GMT by M : So far: they report zero lost packets in the transmission, but one of the two independent data-collection systems is apparently giving some problems. Update: 01/14 21:40 GMT by J : The news is pretty much all good: a very successful mission. Expect to see many photos within hours, but for now apparently only three have been released. Ice blocks or rolling stones -- let the debates begin!

Comments

Re:Any pics yet?

[dtolman]

Spaceflightnow.com indicates that they are now recieving data - so we could be getting the goods as early as this afternoon...

Minor explanation

[Cyclotron_Boy]

They didn't stop recording data because Huygens went silent. Rather, Cassini had to turn to transmit its load of data. Cassini had to turn for a number of reasons ranging from the azimuth and elevation of the lander (now it is more than a probe...) with respect to the horizon, to the maximum data storage capability of Cassini itself. Not that the poster said anything wrong, it was just misleading. I believe Huygens was still transmitting at least carrier verified by Colorado (not sure which radiotelescope picked it up in the US) after Cassini was tasked to turn away. We just couldn't listen much longer, and Huygens' batteries weren't supposed to do more than 4.5 hours anyway (IIRC).
-F

images to be posted at ...

[MoobY]

The images will be posted from the moment they are available at

http://www.lpl.arizona.edu/%7Ekholso/data.htm

Re:Congrats to the ESA

[slungsolow]

Here is a page with the examples of the image output.

http://www.lpl.arizona.edu/~kholso/test_images.htm

Pretty neat.

Plutonium Toxicity

[caveat]

From the excellent Nuclear Weapons FAQ:

Although plutonium presumably exhibits chemical toxicity like other heavy metals, this effect is insignificant (in fact, unobservable) compared to its radiotoxicity. Plutonium's toxic properties are due to the fact that it is an active alpha emitter. Alpha particles are hazardous only if they are emitted inside the body (i.e. the plutonium has been ingested).
...
Swallowing 500 mg (7 curies) of plutonium as a finely divided or soluble material can cause death from the acute exposure of the GI tract in several days to a few weeks. Inhalation of 100 mg (1.4 Ci) of plutonium as particles of optimal size for lung retention can cause death from lung edema in 1 to 10 days. An inhaled dose of 20 mg (0.28 Ci) will cause death by fibrosis in about 1 month. In doses much below these values, the chronic carcinogenic effects become the important ones.

It's not botulinum toxin, but it IS some pretty nasty stuff to have in you.

Planetary Society's blogging from mission control

[FleaPlus]

I'd like to point out again that Emily Lakdawalla of the Planetary Society is running a blog from Huygens mission control in Darmstadt, Germany. The blog is being updated as events happen.

I particularly enjoyed this quote from the blog:

He [John Zarnecki, the PI on the Surface Science Package] also said that it looks like the probe lasted about 147 minutes, which is 12 minutes longer than the predicted 135, but is "well within the error bars" of the predictions. However, he said this was still an early result--he didn't want to say for certain, because the members of a team had a bet on, and the number "looked suspiciously like the one I picked," Zarnecki said. ...

But, when pushed, scientists can't help doing just a little bit of speculating. That's how they work. So here are a couple of little initial tidbits of speculative potential facts that they have mentioned.

Number 1: Since the probe lasted for a really long time, it's "probably a good conclusion" that the probe landed on a solid, not a liquid surface, Lebreton said when he was pushed. Of course, that doesn't rule out John Zarnecki's "squelchy" surface prediction.

Number 2: One thing that may have helped the probe last a long time was that it appeared to stay unexpectedly warm. At an elevation of only 50 kilometers (about 30 miles) above the surface, her interior was still at a balmy 25 C (77 F), despite the outside temperature being a frigid -180 C (-290 F). Lebreton wasn't ready to say what this might mean. It could be overperformance of the spacecraft, but it could also mean a wide variety of unexpected things about the atmosphere. For those of you who like instant results, I think you'll be disappointed on an answer to this question, because after all Huygens was a mission focused almost entirely on Titan's atmosphere, so it's going to take a very long time to synthesize scientific conclusions from all of this.