Cassini/Huygens Mission Update Thread Pt. 2

[centsworth_II]

<font color="yellow">"...silver lined orange clouds!"</font><br /><br />Way too bright to be sun, or Saturn, shine. Must be lightning! <div class="Discussion_UserSignature"> </div>

 

[volcanopele2]

Not to mention the rings....

 

[Leovinus]

<i> W00006235.jpg was taken on April 16, 2005 and received on Earth April 17, 2005. The camera was pointing toward TITAN at approximately 48,957 kilometers away, and the image was taken using the CB3 and CL2 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>

 

[vogon13]

Kinda fjordish looking, but I think the scale is too big for that. <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>

 

[larper]

Slartibartfast must have been in charge here. <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>

 

[Leovinus]

Check out JPL's new Saturn Moon Page. <div class="Discussion_UserSignature"> </div>

 

[davp99]

Excellent Link , Thanx Leo <div class="Discussion_UserSignature"> <font size="4">Dave..</font> </div>

 

[alokmohan]

Helpful refence.

 

[Leovinus]

<i>These three views of Titan from the Cassini spacecraft illustrate how different the same place can look in different wavelengths of light. Cassini's cameras have numerous filters that reveal features above and beneath the shroud of Titan's atmosphere.<br /><br />The first image, a natural color composite, is a combination of images taken through three filters that are sensitive to red, green and violet light. It shows approximately what Titan would look like to the human eye: a hazy orange globe surrounded by a tenuous, bluish haze. The orange color is due to the hydrocarbon particles which make up Titan's atmospheric haze. This obscuring haze was particularly frustrating for planetary scientists following the NASA Voyager mission encounters in 1980-81. Fortunately, Cassini is able to pierce Titan's veil at infrared wavelengths. A single view of this composite is also available (see PIA06230).<br /><br />The second, monochrome view shows what Titan looks like at 938 nanometers, a near-infrared wavelength that allows Cassini to see through the hazy atmosphere and down to the surface. The view was created by combining three separate images taken with this filter, in order to improve the visibility of surface features. The variations in brightness on the surface are real differences in the reflectivity of the materials on Titan. A single view of this image is also available (see PIA06228).<br /><br />The third view, which is a false-color composite, was created by combining two infrared images (taken at 938 and 889 nanometers) with a visible light image (taken at 420 nanometers). Green represents areas where Cassini is able to see down to the surface. Red represents areas high in Titan's stratosphere where atmospheric methane is absorbing sunlight. Blue along the moon's outer edge represents visible violet wavelengths at which the upper atmosphere and detached hazes are better seen. A single view of this composite is also available (see PIA06229).<br /><br />A similar false</i> <div class="Discussion_UserSignature"> </div>

 

[teije]

http://www.spaceflightnow.com/cassini/050426enceladus.html<br /><br /><font color="yellow"> Enceladus is rapidly becoming a very interesting target for Cassini. So much so that scientists and engineers are planning to revise the altitude of the next flyby to get a closer look. Additional Cassini encounters with Enceladus are scheduled for July 14, 2005, and March 12, 2008. The July 14 flyby was to be at an altitude of 1,000 kilometers (620 miles), but the mission team now plans to lower that altitude to about 175 kilometers (109 miles). This will be Cassini's lowest-altitude flyby of any object during its nominal four-year tour. </font><br /><br />WHOAH! Cassini can almost 'reach out and touch' at that altitude. Impressive....<br />Teije<br />

 

[sacha]

The two last flyby of Enceladus, Cassini have stopped imagery at few thousands kms, to protect itselve from moon's <br />atmospheric particles. I guess we will don't expect more accurate imagery. Cassini team will use others instruments ? Or the risk is assumed ?<br /><br />

 

[anoolios]

A UA News article (link): Cassini's Radar and VIMS Instruments Eye Impact Crater on Titan

 

[Leovinus]

<i>With this false-color view, Cassini presents the closest look yet at Saturn's small moon Epimetheus (epp-ee-MEE-thee-uss).<br /><br />The color of Epimetheus in this view appears to vary in a non-uniform way across the different facets of the moon's irregular surface. Usually, color differences among planetary terrains identify regional variations in the chemical composition of surface materials. However, surface color variations can also be caused by wavelength-dependent differences in the way a particular material reflects light at different lighting angles. The color variation in this false-color view suggests such "photometric effects" because the surface appears to have a more bluish cast in areas where sunlight strikes the surface at greater angles.<br /><br />This false color view combines images obtained using filters sensitive to ultraviolet, polarized green and infrared light. The images were taken at a Sun-Epimetheus-spacecraft, or phase, angle of 115 degrees, thus part of the moon is in shadow to the right. This view shows an area seen only very obliquely by NASA's Voyager spacecraft. The scene has been rotated so that north on Epimetheus is up.<br /><br />The slightly reddish feature in the lower left is a crater named Pollux. The large crater just below center is Hilairea, which has a diameter of about 33 kilometers (21 miles). At 116 kilometers (72 miles) across, Epimetheus is slightly smaller than its companion moon, Janus (181 kilometers, or 113 miles across), which orbits at essentially the same distance from Saturn.<br /><br />The images for this color composite were obtained with the Cassini spacecraft narrow-angle camera on March 30, 2005, at a distance of approximately 74,600 kilometers (46,350 miles) from Epimetheus. Resolution in the original images was about 450 meters (1,480 feet) per pixel. This view has been magnified by a factor of two to aid visibility. </i> <div class="Discussion_UserSignature"> </div>

 

[thechemist]

The DISR team has posted three new spectacular mosaics of the Huygens landing area from different altitudes, <br />indicating the probe's descent from 15km, 4km and 500m !!<br /><br />http://www.lpl.arizona.edu/%7Ekholso/ <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[thechemist]

There is also a bunch of new Titan 'T5' Flyby Images posted on May 2 at CICLOPS. <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[teije]

Does Huygens actually float back in the direction it came from in the last image? Wow, I never saw that before. <img src="/images/icons/smile.gif" /><br />

 

[thechemist]

Yes Huygens does actually float back, I had no idea it did either <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[xflare]

Where are the new pictures? Nothing new for a week.......and before that they'd slowed to a trickle.

 

[zavvy]

<b>New Moon Making Waves</b><br /><br />LINK<br /><br />The NASA/ESA/ASI Cassini spacecraft has confirmed earlier suspicions of an unseen moon hidden in a gap in Saturn's outer A ring. A new image shows the new moon and the waves it raises in the surrounding ring material.<br /> <br />The moon, provisionally named S/2005 S1, was first seen in a time-lapse sequence of images taken on 1 May 2005, as Cassini began its climb to higher inclinations in orbit around Saturn. A day later, an even closer view was obtained, which allowed the moon's size and brightness to be measured. <br />The images show the tiny object in the centre of the Keeler gap and the wavy patterns in the gap edges that are generated by the moon's gravitational influence. The Keeler gap is located about 250 kilometres inside the outer edge of the A ring, which is also the outer edge of the bright main rings. <br /><br />The new object, or 'moonlet', is about 7 kilometres across and reflects about half the light falling on it - a brightness that is typical of the particles in the nearby rings. It orbits approximately 136 505 kilometres from the centre of Saturn. More Cassini observations will be needed to determine whether the moon's orbit around Saturn is circular or 'eccentric'(like an oval). <br /><br />S/2005 S1 is the second known moon to exist within Saturn's rings. The other is Pan, 25 kilometres across, which orbits in the Encke gap. Atlas and other moons exist outside the main ring system, as do the two F ring 'shepherd' moons, Prometheus and Pandora. <br /><br />Imaging scientists had predicted the new moon's presence and its orbital distance from Saturn after last July's sighting of a set of peculiar spiky and wispy features in the Keeler gap's outer edge. The similarities of the Keeler gap features to those noted in Saturn's F ring and the Encke gap led imaging scientists to conclude that a small body, a few kilom

 

[Leovinus]

Here's the pic. <div class="Discussion_UserSignature"> </div>

 

[douglas_clark]

Leo,<br /><br />That is an amazing picture. How does shepherding work? It looks like the satelite is about to bump into a ring. Has the satellite done the opposite and cleared a channel for itself? Biggest rock on the block?<br /><br />Thought provoking stuff.<br /><br />douglas

 

[teije]

Question:<br />Looking at the pic it seems that the 'waves' on the outer rings are trailing the moon, but on the inner side they are leading! (For this I am assuming that the picture is taken from below and the moon is in a prograde orbit. Maybe this is a false assumption. Anyone?) I don't understand that at all. I would expect both sides to be trailing. Basically like bowwaves. How does the 'wave' process work?<br /><br />Thanks adv.<br />Teije

 

[vogon13]

Disturbance trails on slower orbiting rings outside orbit of moon, and leads on faster orbiting rings inside of orbit of moon.<br /><br /> <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>

 

[Leovinus]

Right. Assume the inner ring particles have already passed the moon since they orbit faster. That's why the waves appear to lead the moon. <div class="Discussion_UserSignature"> </div>

 

[zavvy]

<b>First Full Mosaics of Titan’s Surface</b><br /><br />LINK<br /><br />As the large amount of data collected by the ESA Huygens probe during its descent onto Titan is being processed, new views of this fascinating world become available.<br /> <br />The Descent Imager Spectral Radiometer (DISR) team have now produced the first complete ‘stereographic’ and ‘gnomonic’ mosaic images. Using special image projection techniques, the team combined a series of images captured by Huygens while rotating on its axis at an altitude of about 20 kilometres. <br />The DISR on board Huygens took its series of photographs of the ever-approaching surface in sets of three, or ‘triplets’, as it dropped through Titan’s atmosphere on 14 January this year. The images sent back to Earth partially overlap, due to the probe’s rotation during the descent and due to the overlap between the fields of view of the different cameras. <br /><br />DISR scientists are studying these images for similarities, such as physical features common to more than one image, and are constructing ‘mosaics’, like jigsaw puzzles. <br /> <br />There are many different ways of rendering three-dimensional objects into two dimensions. Different kinds of projections for maps or photographs are able to represent realistically things like size, areas, distances and perspective. One particular kind of projection used for spheres in two dimensions (for example on some maps of Earth or the celestial sphere) is ‘stereographic’ projection. <br /><br />A ‘gnomonic’ projection has also been produced, and this tends to make the surface appear as if it was flat. This type of projection is often found on maps used by navigators and aviators in determining the shortest distance between two points. However there is a lot of distortion of scale at the outer edges of gnomonic projections. <br /><br />On the stereographic view, like that through a ‘fish-eye’ l