Cassini/Huygens Mission Update Thread Pt. 2

[Leovinus]

Part 1 was getting too big. <div class="Discussion_UserSignature"> </div>

 

[grooble]

So where are all these processed images some of you were saying would come out?

 

[yurkin]

Not yet, but Planetary Society has some processed sounds<br /><br />http://planetary.org/sounds/huygens_sounds.html<br />

 

[alokmohan]

Is there any conclusion from the sound?

 

[centsworth_II]

I think one of the main objectves was to listen for thunder. None was heard. <div class="Discussion_UserSignature"> </div>

 

[grooble]

Not surprised when they compress 2.5 hours of sound into 10 seconds, how are you supposed to pick out things like thunder?

 

[centsworth_II]

I'm sure the scientists are looking for indicators in the raw data, not logging into the planetary society website to do their research. <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

As a casual (yet interested) observer, I havn't seen any announcement of a lightning sighting. However, researchers will be looking for evidence of lightning flashes on each Cassini flyby of Titan. It seems that while haze, mist, and fog are ubiquitous on Titan, clouds are not -- at least at this time. If there is lightning on Titan it may be rare. Even so, with the number of Cassini flybys and the scientists knowing what to look for in the instument data, if it is there at all it should eventually be seen.<br /><br />An internet search using the key words "titan lightning" will bring up several articles on the subject. <div class="Discussion_UserSignature"> </div>

 

[Leovinus]

From the most recent raw image page:<br /><br /><i> N00027905.jpg was taken on February 12, 2005 and received on Earth February 12, 2005. The camera was pointing toward TITAN, and the image was taken using the IRP0 and CB3 filters. This image has not been validated or calibrated. A validated/calibrated image will be archived with the NASA Planetary Data System in 2005. </i> <div class="Discussion_UserSignature"> </div>

 

[Leovinus]

<i>Reflected light from Saturn dimly illuminates the night side of the cratered moon Mimas in this Cassini image. Above, the outer edges of the planet's main rings show some interesting details. Mimas is 398 kilometers (247 miles) across.<br /><br />Several thin ringlets comprising the F ring are nicely visible here, and the bright core of the ring displays a few twisted knots. Perhaps less noticeable are kinks in one of the thin ringlets of material visible within the Encke Gap near the upper left corner. The outer edge of the A ring appears notably brighter than the ring material on the other side of the narrow Keeler Gap. Finally, numerous gravitational resonances give the A ring a grooved or striped appearance in this view.<br /><br />The image was taken in visible light with the Cassini spacecraft narrow angle camera on Jan. 17, 2005, at a distance of approximately 1.2 million kilometers (746,000 miles) from Saturn. The image scale is 7 kilometers (4 miles) per pixel. </i> <div class="Discussion_UserSignature"> </div>

 

[Leovinus]

<i>A huge annular feature with an outer diameter of approximately 440 kilometers (273 miles) appears in this image taken with Cassini's Titan radar mapper. It resembles a large crater or part of a ringed basin, either of which could be formed when a comet or asteroid tens of kilometers in size slammed into Titan. This is the first impact feature identified in radar images of Titan.<br /><br />The surface of Titan appears to be very young compared to other Saturnian satellites. In Titan's case, debris raining down from the atmosphere or other geologic processes may mask or remove the craters. The pattern of brightness suggests that there is topography associated with this feature; for example, in the center of the image there appear to be mounds each about 25 kilometers (15 miles) across. Since they are dark on their lower edges that face away from the radar and bright on the opposite face, they must be elevated above the surrounding terrain.<br /><br />This image is a part of a larger swath acquired on Feb. 15, 2005, on Cassini's second opportunity to map Titan's surface via radar. Seams between radar segments are visible as horizontal, sawtooth-shaped lines. </i> <div class="Discussion_UserSignature"> </div>

 

[vogon13]

It would take a hellish nuke to make a crater that size, impacting body must have been pretty big, like bigger than some of the co-orbitals and ring shepherds. I suspect this blast exceeded Tellers' threshold for blowing atmosphere above blast into space. Where does this material go? Titan torus has been observed, this could be one mechanism for its replenishment. Once in torus, does gas stay put in Titan orbit area or is there a mechanism for expelling gas from Saturn system, or a mechanism for pulling gas closer in to Saturn? I believe rockets have been fired from earth to dump tracer (IIRC sodium?) into Van Allen belts and beyond so wouldn't similar mechanism operate in Saturn system? <br /><br />I wonder how many craters in this size range are on Titan? Radar has done 2% of surface, are we happy with stats yet? <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[thalion]

Incredible image. If that really is a crater, it would be one of the largest in the Solar System; I, too, shudder at the thought of the impactor that could blasted such an immense scar.

 

[claywoman]

To me, seeing the size of this crater makes me think that even moons are hardy creations, I wonder how it stayed together? wouldn't something that massive break our moon apart?

 

[Leovinus]

<i>These images of Saturn's polar aurora were taken by NASA's Hubble Space Telescope on Jan. 24, 26, and 28. Each of the three images of Saturn combines ultraviolet images of the south polar region (to show the auroral emissions) with visible wavelength images of the planet and rings. The Hubble images were obtained during a joint campaign with NASA's Cassini spacecraft to measure the solar wind approaching Saturn and the Saturn kilometric radio emissions. The strong brightening of the aurora on January 26 corresponded with the recent arrival of a large disturbance in the solar wind. These results are presented in three papers, which appear in the Feb. 17 issue of the journal Nature.</i> <div class="Discussion_UserSignature"> </div>

 

[Leovinus]

<i>The oddball shapes of Saturn's small ring moons Prometheus and Epimetheus are discernible in the view from Cassini. Saturn's shadow carves a dark, diagonal swath across the ring plane, even occulting the outer edge of thin, knotted F ring. Prometheus is 102 kilometers, or 63 miles across, while Epimetheus is 116 kilometers, or 72 miles across.<br /><br />Prometheus is visible inside the F ring near center, and Epimetheus is seen near the lower right corner. North on Saturn is to the upper right. The view is from beneath the ring plane.<br /><br />The image was taken in visible light with the Cassini spacecraft narrow angle camera on Jan. 22, 2005, at a distance of approximately 2.6 million kilometers (1.6 million miles) from Saturn. The image scale is 15 kilometers (9 miles) per pixel. </i> <div class="Discussion_UserSignature"> </div>

 

[Leovinus]

There was a close flyby of ENCELADUS yesterday. The latest raw images are something you need to look at. <div class="Discussion_UserSignature"> </div>

 

[chew_on_this]

Post deleted by chew_on_this

 

[Leovinus]

That's not a better link: It has the earlier flyby of Titan on it. My link has the later flyby of Enceladus. <div class="Discussion_UserSignature"> </div>

 

[chew_on_this]

nice switcheroo, cute trick

 

[bobvanx]

The Cassini radar images show features which might be below the surface, according to the Cassini website. How much penetrating power does this radar have? Could they image subsurface features on Enceladus?

 

[chew_on_this]

I'm not sure if they are taking radar images. The only thing I've seen so far are RAW images. That would be an interesting image to gather possible subsurface data.<br />False color imagery should also give some interesting signatures. Guess we'll have to wait and see.

 

[fangsheath]

It depends on the transparency of the surface material to the radar beam, but keep in mind that the wavelengths have been chosen so as to not miss too much, so I doubt there is much penetration in general.

 

[claywoman]

WOW!!! All I can say is WOW!!!<br /><br />It looks like a huge snowball with glacial mountains and valleys?

 

[peteb]

In response to your earlier comment about the first impact feature that the radar saw, it was not close to being large enough to disrupt Titan - it's about 7-8% of Titan's diameter. It is the distinctive multiring feature in the upper half of this earlier image:<br />http://photojournal.jpl.nasa.gov/catalog/PIA06154 <br /><br />As far as the Moon goes, the South Pole-Aitken basin is far larger:<br />http://antwrp.gsfc.nasa.gov/apod/ap960906.html