Cassini's Robot Lab Successfully Separates

toomanyairmiles writes "The BBC has an article indicating NASA's Cassini probe has successfully launched its robot lab on its three-week journey into the atmosphere of Saturn's moon Titan. 'Such is the chemistry and temperature (-180C) on Titan that scientists suspect it may harbour lakes, even great seas, of methane or ethane.' Seemingly we have very little idea of what we'll find there: 'Even Cassini's remarkable instruments have struggled to get at the facts. Scientists can see dark and bright regions on the surface, but quite what they represent no one is really sure.'"

Comments

Re:Huygens

[spiny]

http://www-gap.dcs.st-and.ac.uk/~history/Mathemati cians/Huygens.html

Hooray for NASA/ESA collaboration

[ikewillis]

For those who don't know, the Hyugens probe bound for Titan was developed by the EU's Space Agency. It will provide us with the first glimpses below Titan's cloudy surface, and was carried by NASA's Cassini probe.

It's wonderful to see such collaboration between the ESA and NASA, and I hope we continue to see such efforts in the future.

Re:Hooray for NASA/ESA collaboration

[Anonymous Coward]

While we're educating - the EU does not have a space agency. The European Space Agency is it's own (or it's member nations...), and not a part of the EU. A few countries who are not in the EU are in ESA (hell, even Canada is - though they're a little special :). I still find the collaboration wonderful though - the world would be a better place with some more of that...

Re:Hooray for NASA/ESA collaboration

[drachton]

ESA page for the Cassini-Huygens mission. They have a couple of Flash animations, some nice pictures of Titan (here) and an interesting factsheet on the mission.

Image of the Huygens/Cassini separation

[ikewillis]

Here's an excellent image of the seperation of the Cassini spacecraft with the Huygens probe bound for Titan:

http://planetary.org/saturn/images_spacecraft.html

To clarify...

[ethnocidal]

Cassini-Huygens is a joint mission between NASA and the European Space Agency - http://www.esa.int/. Cassini (the main vehicle) is NASA's responsibility, and the robot probe called Huygens is ESA's.

Good to see some international cooperation in a venture like this. After the stunning shots of Titan and Saturn returned by Cassini's sensors, we can only hope that the remote probe fares better than Beagle 2 :) ESA article with more information

Re:To clarify...

[snake_dad]

Good to see some international cooperation in a venture like this.

If that aspect of this mission is news to you, you will probably be surprised to know that in many NASA missions there are several non-US instruments. An example that comes to mind is the Mossbauer Spectrometer on the instrument arm of the current Mars rovers. This experiment was built by a German university (IIRC). Another example of cooperation would be the tests that were done on Mars, sending data to Earth from the rovers, through the European Mars Express spacecraft. And it is the same with European spacecraft, many include American experiments.

And if it wasn't news to you it probably was news to someone else reading this :)

Re:i know

[Anonymous Coward]

you'd need oxygen for the reaction you're expecting.

Re:I Wanna See Rain!

[myowntrueself]

"when the rain falls, it will be like normal rain at first because higher up in the air it will be colder and the methane/ethane will be liquid, but as it gets closer to the surface, it will turn into a gas as it warms up, so the rain will turn from liquid into a gas before it reaches the surface, and will then rise upwards."

Actually this already happens here on Earth (only with water).

There are desert areas (Sahara included IIRC) where sometimes it rains and the rain evaporates before it can hit the ground.

I believe its called 'ghost rain'

Re:I Wanna See Rain!

[NoseBag]

In Arizona, its called Virga i.e. rain that never reaches the ground.

Its actually quite neat to see in the distance. You can see the downpour falling, usually from under a nice dark thundercloud (uh, where else?), and then it kinda gets fuzzy and vague, and then it just....isn't. The "isn't" boundary also moves up and down slowly - due to air currents and such, I guess. Its quite peaceful to observe.

Re:Hmmm.

[crymeph0]

Venus is the planet which was supposed to have jungles.

You make a valid point about over-speculating, but at least the speculation about Titan is based on the fact that the temperatures at Titan are in the right range for methane to be liquid, solid, and gas. So it's not just some dreamer's wild vision.

I'd say there's definitely some sort of liquid action going on though, because there aren't that many impact craters from what they have been able to tell, which indicates that the surface has been recently eroded. It could be volcanism too, I guess, but I would think we'd have detected some chemical signatures of that even without being able to see the surface that clearly. Any chemists in the audience, please feel free to prove me wrong.

Re:Not enough time on the surface

[Anonymous Coward]

It will have been doing major science for over two hours by the time it lands, including taking pictures all the way down. Whatever it does on the surface is 'bonus' time. And no, if it splashes down in a lake, it will not sink. In fact, it has an instrument that will use sonar to try and determine the depth of the lake. Also, whatever it does on the surface is constrained not just by battery life, but by communications with Cassini -- which will vanish over Titan's horizon about an hour after the probe lands.

fortunately, doppler has been sidestepped.

[bmfs]

Remain silent? There was a BBC Horizon documentary on this very subject broadcast earlier this year. You can read more about the problem and the solution here:

http://www.spectrum.ieee.org/WEBONLY/publicfeature /oct04/1004titan.html

And here:

http://www.bbc.co.uk/sn/tvradio/programmes/horizon /saturn_prog_summary.shtml

Problem: Italian Company (Alenia Spazio) responsible for comms corrected for doppler shift on the carrier signal, but not on the data rate. Alenia Spazio's insistence on confidentiality may have played a role in this oversight. NASA reviewers were never given the specs of the receiver. As JPL's [Robert] Mitchell explained, "Alenia Spazio considered JPL to be a competitor and treated the radio design as proprietary data."

Solution: Altered the trajectory of Cassini / Huygens so that Huygens is moving parallel to Cassini during descent, sidestepping the doppler shift issue.

Cassini images of Titan's surface

[valdean]

Wired News has some pictures of Titan's surface taken by Cassini. The article explains somewhat the new questions the images have created, and what the Huygens mission hopes to accomplish in terms of answering those questions, including this explanation for the bright/dark spots:

Do the dark areas in the radar images of Titan's surface signify the existence of lakes?

When radar waves are used to create images of surfaces, areas that reflect more radio waves turn up as bright spots, while those that reflect fewer waves appear as dark spots. Some scientists believe the large, dark patches in the Titan images could be lakes full of liquid ethane and propane, which would absorb radio waves. But if this is true, do the lakes have ripples and waves caused by the wind, or are they completely still?

http://www.wired.com/news/space/0,2697,65533,00.ht ml

Re:Black and white

[Science]

Yes, they use B&W cameras. Astronomers are interested in detail first color second. Color cameras don't have the resolution of B&W. Color images are created by taking three idential B&W images through three different color filters. When combined and processed, the three B&W images produce a color image.