Cassini/Huygens Mission Update Thread Pt. 2

[Leovinus]

<i>Not since NASA's Voyager 1 spacecraft saw our home as a pale blue dot from beyond the orbit of Neptune has Earth been imaged in color from the outer solar system. Now, Cassini casts powerful eyes on our home planet, and captures Earth, a pale blue orb -- and a faint suggestion of our moon -- among the glories of the Saturn system.<br /><br />Earth is captured here in a natural color portrait made possible by the passing of Saturn directly in front of the sun from Cassini’s point of view. At the distance of Saturn’s orbit, Earth is too narrowly separated from the sun for the spacecraft to safely point its cameras and other instruments toward its birthplace without protection from the sun’s glare.<br /><br />The Earth-and-moon system is visible as a bright blue point on the right side of the image above center. Here, Cassini is looking down on the Atlantic Ocean and the western coast of north Africa. The phase angle of Earth, seen from Cassini is about 30 degrees.<br /><br />A magnified view of the image taken through the clear filter (monochrome) shows the moon as a dim protrusion to the upper left of Earth. Seen from the outer solar system through Cassini’s cameras, the entire expanse of direct human experience, so far, is nothing more than a few pixels across.<br /><br />Earth no longer holds the distinction of being our solar system’s only “water world,” as several other bodies suggest the possibility that they too harbor liquid water beneath their surfaces. The Saturnian moon, Enceladus, is among them, and is also captured on the left in this image (see inset), with its plume of water ice particles and swathed in the blue E ring which it creates. Delicate fingers of material extend from the active moon into the E ring. See PIA08321, for a more detailed view of these newly-revealed features.<br /><br />The narrow tenuous G ring and the main rings are seen at the right.<br /><br />The view looks down from about 15 degrees above the un-illuminated side of the rings.<br /><br></br></i> <div class="Discussion_UserSignature"> </div>

 

[telfrow]

<b>New ring discovered around Saturn</b><br /><br /><i>The Cassini spacecraft has identified a faint, previously unknown ring circling the giant planet Saturn.<br /><br />It appears to be composed of material blasted off the surface of two saturnian moons by meteoroid impacts.<br /><br />The moons Janus and Epimetheus may be too small to hold on to dust kicked out by these impacts, so it escapes into space, spreading out into a ring.<br /><br />The tenuous, wispy ring coincides with the orbits of these two moons, mission scientists noted.<br /><br />Researchers expected meteoroid impacts on Janus and Epimetheus to kick particles off the moons' surfaces and inject them into an orbit around Saturn. But they were surprised to find such a well-defined ring at this location. </i><br /><br />Link <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[telfrow]

<b>Titan's "Kissing Lakes"</b><br />September 26, 2006 <br />Full-Res: PIA08740<br /><br /><i>This Cassini radar image shows two lakes "kissing" each other on the surface of Saturn's moon Titan.<br /><br />The image from a flyby on Sept. 23, 2006, covers an area about 60 kilometers (37 miles) wide by 40 kilometers (25 miles) high.<br /><br />This pass was primarily dedicated to the ion and neutral mass spectrometer instrument, so although, the volume of radar data was small, scientists were amazed to see Earth-like lakes. With Titan's colder temperatures and hydrocarbon-rich atmosphere, however, the lakes likely contain a combination of methane and ethane, not water.<br /><br />In this image, near 73 degrees north latitude, 46 degrees west longitude, two lakes are seen, each 20 to 25 kilometers (12 to 16 miles) across. They are joined by a relatively narrow channel. The lake on the right has lighter patches within it, indicating that it may be slowly drying out as the northern summer approaches. </i><br /><br />Link <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[telfrow]

<b>Shorefront Property, Anyone?</b><br />September 26, 2006 <br />Full-Res: PIA08741<br /><br /><i>This lake is part of a larger image taken by the Cassini radar instrument during a flyby of Saturn's moon Titan on Sept. 23, 2006. It shows clear shorelines that are reminiscent of terrestrial lakes. With Titan's colder temperatures and hydrocarbon-rich atmosphere, however, the lakes likely contain a combination of methane and ethane, not water.<br /><br />Centered near 74 degrees north, 65 degrees west longitude, this lake is roughly 20 kilometers by 25 kilometers (12 to 16 miles) across. It features several narrow or angular bays, including a broad peninsula that on Earth would be evidence that the surrounding terrain is higher and confines the liquid. Broader bays, such as the one seen at right, might result when the terrain is gentler, as for example on a beach. </i><br /><br />Link <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[telfrow]

<b>Saturn's Silhouetted Clouds</b><br />October 5, 2006 <br />Full-Res: PIA08732<br /><br /><i>This false-color mosaic of Saturn shows deep-level clouds silhouetted against Saturn's glowing interior. The image was made with data from Cassini's visual and infrared mapping spectrometer, which can image the planet at 352 different wavelengths.<br /><br />This mosaic shows the entire planet, including features like Saturn's ring shadows and the terminator, the boundary between day and night.<br /><br />The data were obtained in February 2006 at a distance of 1.6 million kilometers (1 million miles) from directly over the plane of Saturn's rings, which appear here as a thin, blue line over the equator. The image was constructed from images taken at wavelengths of 1.07 microns shown in blue, 2.71 microns shown in green, and 5.02 microns shown in red.<br /><br />The blue-green color (lower right) is sunlight scattered off clouds high in Saturn's atmosphere and the red color (upper left) is the glow of thermal radiation from Saturn's warm interior, easily seen on Saturn's night side (top left), within the shadow of the rings, and with somewhat less contrast on Saturn's day side (bottom right). The darker areas within Saturn show the strongest thermal radiation. The bright red color indicates areas where Saturn's atmosphere is relatively clear. The great variety of cloud shapes and sizes reveals a surprisingly active planet below the overlying sun-scattering haze.<br /><br />The brighter glow of the northern hemisphere versus the southern indicates that the clouds and hazes there are noticeably thinner than those in the south. Scientists speculate that this is a seasonal effect, and if so, it will change as the northern hemisphere enters springtime during the next few years. </i><br /><br />Link <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[telfrow]

<b>The Color of Darkness</b><br />October 6, 2006 <br />Full-Res: PIA08282<br /><br /><i>Sunlight filters through Saturn's rings in sepia tones in this artful view from the Cassini spacecraft of the dark side of the rings. Those rays from the sun directly reflected from the lit side of the rings onto the planet strike and illuminate the night-side southern hemisphere.<br /><br />The densely populated B ring blocks much of the Sun's light and thus looks quite dark.<br /><br />Tethys (1,071 kilometers, or 665 miles across) is a mere sliver below left.<br /><br />Unprocessed wide-angle camera images taken in a high-phase viewing geometry generally contain stray light artifacts. These have largely been removed from this image by computer image processing.<br /><br />Cassini was about 3 degrees above the ringplane when this image was obtained on Sept. 6, 2006. Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were taken using the Cassini spacecraft wide-angle camera at a distance of approximately 1.8 million kilometers (1.1 million miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 154 degrees. Image scale is 106 kilometers (66 miles) per pixel. </i><br /><br />Link <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[telfrow]

<b>The Spoke Search</b><br />October 5, 2006 <br />Full-Res: PIA08288<br /><br /><i>A group of bright spokes tightly cluster together in Saturn's B ring. The spokes seen here generally all exhibit the same degree of shearing, or tilting, but some deviations are apparent. In this image, the direction to Saturn is downward; orbital motion is to the left.<br /><br />Ring scientists are eager for data to help them understand and eventually explain how these mysterious ring features are created. To that end, Cassini has been directed to acquire movie sequences, like the one this image is part of, that watch for these elusive radial structures.<br /><br />This observation focused on the morning side of the rings, the side where the rings are rotating out from Saturn's shadow. Spokes appear most frequently at this location.<br /><br />Also barely visible in this image are broader, much fainter but still bright radial regions that extend over larger radial distances than the spokes in the upper left. Where these fainter features cross ringlets in the lower part of the image, slight variations in brightness are apparent. These are probably due to tiny particles, possibly part of a former spoke, that haven't yet settled down onto the ring plane.<br /><br />Although their formation is still a subject of inquiry, scientists are confident that the microscopic spoke particles are slightly electrically charged and therefore are influenced by Saturn's magnetic field.<br /><br />The brightness of the spokes, when combined with viewing geometry information and estimates of their particle sizes can help researchers determine the amount of material in the spokes--a crucial quantity to constrain theories of spoke formation.<br /><br />The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 28, 2006, at a distance of approximately 1.3 million kilometers (800,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 147 degrees. Scale in the original</i> <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[telfrow]

October 9 Titan Flyby <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[jmilsom]

Those images of Helene are amazing. I realise Dione's trojan is only 32km across, but those features look massive in respect to her size. How tall do you think the jutting feature on the near side is? <div class="Discussion_UserSignature"> </div>

 

[yevaud]

All:<br /><br />This thread is now over 600 posts, and will be closed and unpinned. Please continue your discussion in Cassini/Huygens Mission Update Thread Pt. 3.<br /><br />Thanks. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>