Cassini/Huygens Mission Update Thread

[remcook]

PaulVWWhalen: i think this is about as you can get:<br /><br />http://huygens.esa.int/science-e/www/object/index.cfm?fobjectid=36396<br /><br />not much there. Maybe at the archived press conferences they tell a little bit more

 

[Leovinus]

<i>In the dim light of the outer solar system, Cassini gazed back at Saturn's brightest gem -- the moon Enceladus. The icy little world presents only a slim crescent in this natural color view.<br /><br />Cassini has now matched the best spatial resolution on Enceladus achieved by NASA's Voyager spacecraft, and will soon have excellent coverage of the moon (at more than 10 times the resolution in this image), following a flyby planned for February 17.<br /><br />When seen from its day side, Enceladus (499 kilometers, or 310 miles across) has one of the brightest and whitest surfaces in the solar system. Since it reflects most of the sunlight that strikes it, the temperature there remains at a chilly -200 degrees Celsius (-330 degrees Fahrenheit).<br /><br />In this view, Cassini was pointed at the leading hemisphere of Enceladus, which was in darkness at the time. The image has been rotated so that north on Enceladus is up.<br /><br />Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were acquired with the Cassini spacecraft narrow angle camera on Jan. 16, 2005, at a distance of approximately 209,300 kilometers (130,100 miles) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 148 degrees. Resolution in the original image was about 1 kilometer (0.6 miles) per pixel. The image has been contrast-enhanced and magnified by a factor of two to aid visibility. </i> <div class="Discussion_UserSignature"> </div>

 

[Leovinus]

<i> <br />Multimedia - Images - Moons - Mimas <br /><br />Mimas against the azure backdrop of Saturn's northern latitudes<br /><br />Mimas Blues<br />February 8, 2005 Full-Res: PIA06176<br /><br />Mimas drifts along in its orbit against the azure backdrop of Saturn's northern latitudes in this true color view. The long, dark lines on the atmosphere are shadows cast by the planet's rings.<br /><br />Saturn's northern hemisphere is presently relatively cloud-free, and rays of sunlight take a long path through the atmosphere. This results in sunlight being scattered at shorter (bluer) wavelengths, thus giving the northernmost latitudes their bluish appearance at visible wavelengths.<br /><br />At the bottom, craters on icy Mimas (398 kilometers, or 247 miles across) give the moon a dimpled appearance.<br /><br />Images taken using infrared (930 nanometers), green (568 nanometers) and ultraviolet (338 nanometers) spectral filters were combined. The colors have been adjusted to match closely what the scene would look like in natural color. See http://photojournal.jpl.nasa.gov/catalog/PIA06142 for a similar view in natural color.<br /><br />The images were obtained using the Cassini spacecraft narrow angle camera on Jan. 18, 2005, at a distance of approximately 1.4 million kilometers (870,000 miles) from Saturn. Resolution in the image is 8.5 kilometers (5.3 miles) per pixel on Saturn and 7.5 kilometers (4.7 miles) per pixel on Mimas. The image has been contrast-enhanced to aid visibility. </i> <div class="Discussion_UserSignature"> </div>

 

[Leovinus]

<i>Saturn's northern hemisphere is presently a serene blue, more befitting of Uranus or Neptune, as seen in this natural color image from Cassini.<br /><br />Light rays here travel a much longer path through the relatively cloud-free upper atmosphere. Along this path, shorter wavelength blue light rays are scattered effectively by gases in the atmosphere, and it is this scattered light that gives the region its blue appearance. Why the upper atmosphere in the northern hemisphere is so cloud-free is not known, but may be related to colder temperatures brought on by the ring shadows cast there.<br /><br />Shadows cast by the rings surround the pole, looking almost like dark atmospheric bands. The ring shadows at higher latitudes correspond to locations on the ringplane that are farther from the planet -- in other words, the northernmost ring shadow in this view is made by the outer edge of the A ring.<br /><br />Spots of bright clouds also are visible throughout the region. This view is similar to an infrared image obtained by Cassini at nearly the same time (see http://photojournal.jpl.nasa.gov/catalog/PIA06567). The infrared view shows a great deal more detail in the planet's atmosphere, however. Images obtained using red, green and blue spectral filters were combined to create this color view. The images were taken with the Cassini spacecraft wide angle camera on Dec. 14, 2004, at a distance of 719,200 kilometers (446,900 miles) from Saturn. The image scale is about 39 kilometers (24 miles) per pixel. </i> <div class="Discussion_UserSignature"> </div>

 

[zavvy]

<b>First measurement of Titan’s winds from Huygens</b><br /><br />LINK<br /><br />Using a global network of radio telescopes, scientists have measured the speed of the winds faced by Huygens during its descent through the atmosphere of Titan.<br /> <br />This measurement could not be done from space because of a configuration problem with one of Cassini’s receivers. The winds are weak near the surface and increase slowly with altitude up to about 60 km, becoming much rougher higher up where significant vertical wind shear may be present. <br /><br />Preliminary estimates of the wind variations with altitude on Titan have been obtained from measurements of the frequency of radio signals from Huygens, recorded during the probe’s descent on 14 January 2005. These ‘Doppler’ measurements, obtained by a global network of radio telescopes, reflect the relative speed between the transmitter on Huygens and the receiver on the Earth. <br /><br />Winds in the atmosphere affected the horizontal speed of the probe’s descent and produced a change in the frequency of the signal received on Earth. This phenomenon is similar to the commonly heard change in pitch of a siren on a speeding police car. <br /><br />Leading the list of large radio antennas involved in the programme were the NRAO Robert C. Byrd Green Bank Telescope (GBT) in West Virginia, USA, and the CSIRO Parkes Radio Telescope in Australia. Special instrumentation designed for detection of weak signals was used to measure the ‘carrier’ frequency of the Huygens radio signal during this unique opportunity. <br /><br />The initial detection, made with the ‘Radio Science Receivers’ on loan from NASA’s Deep Space Network, provided the first unequivocal proof that Huygens had survived the entry phase and had begun its radio relay transmission to Cassini. <br /><br />The very successful signal detection on Earth provided a surprising turnabout for the

 

[thalion]

^<br />Great news! 120 m/s--whew! Woe betide any high-altitude fliers on Titan in the future. <img src="/images/icons/wink.gif" />

 

[ratliff]

Wow! The animation sure makes it APPEAR like something is flowing over some of the rocks and periodically obscuring some of them in the "channel".....

 

[Leovinus]

<i>Saturn's moon Mimas has many large craters, but its Herschel crater dwarfs all the rest. This large crater 130 kilometers wide (80 miles) has a prominent central peak, seen here almost exactly on the terminator. This crater is the moon's most prominent feature, and the impact that formed it probably nearly destroyed Mimas. Mimas is 398 kilometers (247 miles) across.<br /><br />This view is predominantly of the leading hemisphere of Mimas. The image has been rotated so that north on Mimas is up.<br /><br />This image was taken with the Cassini spacecraft narrow angle camera on Jan. 16, 2005, at a distance of approximately 213,000 kilometers (132,000 miles) from Mimas and at a Sun-Mimas-spacecraft, or phase, angle of 84 degrees. Resolution in the original image was about 1.3 kilometers (0.8 miles) per pixel. A combination of spectral filters sensitive to ultraviolet and polarized light was used to obtain this view. Contrast was enhanced and the image was magnified by a factor of two to aid visibility. </i> <div class="Discussion_UserSignature"> </div>

 

[thalion]

For my part, I'm really looking forward to the Mimas, Enceladus, and Hyperion flybys this year--Hyperion's in particular.

 

[alokmohan]

Can yu tell m what this info may lead to ?

 

[zavvy]

<b>Saturn's moon is Death Star's twin</b><br /><br />LINK<br /><br />Saturn's diminutive moon, Mimas, poses as the Death Star - the planet-destroying space station from the movie Star Wars - in an image recently captured by NASA's Cassini spacecraft.<br /><br />A giant crater 138 kilometres across dominates the landscape of Mimas and represents almost one-third of the moon's diameter.<br /><br />Scientists first noticed Mimas's resemblance to the Death Star when the twin Voyager spacecraft flew past Saturn in 1980 and 1981. The second film in the movie series - The Empire Strikes Back - had just hit movie theatres, recalls Cassini deputy project scientist Linda Spilker. <br /><br />Now, Cassini has taken an even better image than those from the Voyager probes with its narrow-angle camera. It snapped the photo on 16 January 2005 from 213,000 km away at a resolution of 1.3 km per pixel.<br /><br />Heavy fire<br />Like the Death Star, Mimas has found itself on the receiving end of some heavy fire. The crater was probably caused by an enormous asteroid impact. But the moon only just survived - if the asteroid had been any bigger or moving much faster, it probably would have split the moon in two.<br /><br />Most of the craters on Mimas are named after characters in Camelot. But the biggest crater was named after Sir William Herschel, the scientist who discovered Mimas. "Herschel's the oddball crater that doesn't really fit in," Spilker told New Scientist.<br /><br />The peak in the middle of Herschel crater was also formed by the impact, when pulverised or molten rock rebounded upwards like a droplet of water splashing up from a pool of water.<br /><br />NASA's Jet Propulsion Laboratory in Pasadena, California, US, released the image on Thursday.<br /><br />

 

[Leovinus]

. <div class="Discussion_UserSignature"> </div>

 

[bobw]

Just a bump from page 140

Sorry, bad move. Wrong thread.