[BornAgainStar]

The old thread was so full of large picture files, that I decided to start a new one. You can find the old one here.


Official Site



IMO, this picture is by far the most spectacular yet. They are really getting some close-up pictures now.

In a splendid portrait created by light and gravity, Saturn's lonely moon Mimas is seen against the cool, blue-streaked backdrop of Saturn's northern hemisphere. Delicate shadows cast by the rings arc gracefully across the planet, fading into darkness on Saturn's night side.


The part of the atmosphere seen here appears darker and more bluish than the warm brown and gold hues seen in Cassini images of the southern hemisphere, due to preferential scattering of blue wavelengths by the cloud-free upper atmosphere.


The bright blue swath near Mimas (398 kilometers, or 247 miles across) is created by sunlight passing through the Cassini division (4,800 kilometers, or 2,980 miles wide). The rightmost part of this distinctive feature is slightly overexposed and therefore bright white in this image. Shadows of several thin ringlets within the division can be seen here as well. The dark band that stretches across the center of the image is the shadow of Saturn's B ring, the densest of the main rings. Part of the actual Cassini division appears at the bottom, along with the A ring and the narrow, outer F ring. The A ring is transparent enough that, from this viewing angle, the atmosphere and threadlike shadows cast by the inner C ring are visible through it.


Images taken with red, green and blue filters were combined to create this color view. The images were obtained with the Cassini spacecraft narrow angle camera on Nov. 7, 2004, at a distance of 3.7 million kilometers (2.3 million miles) from Saturn. The image scale is 22 kilometers (14 miles) per pixel.

This movie is a condensed version of Cassini's 44-hour approach to Titan. During the movie, the planet rotates about 40 degrees and the spacecraft's distance to the moon ranges from 1,800,000 to 700,000 kilometers (1,000,000 to 435,000 miles). At its closest, on Oct. 26, 2004, Cassini was 1,200 kilometers (745 miles) above the moon. Clouds are seen forming and evolving near the south pole. The images making up this movie were captured by Cassini's imaging science subsystem through near-infrared filters.

[BornAgainStar]

Having now passed closer to Tethys than the Voyager 2 spacecraft, Cassini has returned the best-ever natural color view of this icy Saturnian moon.

As seen here, the battered surface of Tethys (1,060 kilometers, or 659 miles across) has a neutral hue. The image here is a mosaic of two footprints. Three images taken in the red, green and blue filters were taken to form a natural color composite. The result reveals a world nearly saturated with craters ? many small craters lie on top of older, larger ones, suggesting an ancient surface. At the top and along the boundary between day and night, the moon's terrain has a grooved appearance.

This moon is known to have a density very close to that of water, indicating it is likely composed mainly of water ice. Its frozen mysteries await Cassini's planned close flyby in September 2005.

The view shows primarily the trailing hemisphere of Tethys, which is the side opposite the moon's direction of motion in its orbit. The image has been rotated so that north on Tethys is up.

The images comprising this color view were taken with the Cassini spacecraft narrow angle camera on Oct. 28, 2004, at a distance of about 256,000 kilometers (159,000 miles) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 50 degrees. The image scale is 1.5 kilometers (0.9 miles) per pixel.

A mosaic of nine processed images recently acquired during Cassini's first very close flyby of Saturn's moon Titan on Oct. 26, 2004, constitutes the most detailed full-disc view of the mysterious moon.

The view is centered on 15 degrees south latitude, and 156 degrees west longitude. Brightness variations across the surface and bright clouds near the south pole are easily seen.

The images that comprise the mosaic have been processed to reduce the effects of the atmosphere and to sharpen surface features. The mosaic has been trimmed to show only the illuminated surface and not the atmosphere above the edge of the moon. The Sun was behind Cassini, so nearly the full disc is illuminated. Pixel scales of the composite images vary from 2 to 4 kilometers per pixel (1.2 to 2.5 miles per pixel).

Surface features are best seen near the center of the disc, where the spacecraft is looking directly downwards; the contrast becomes progressively lower and surface features become fuzzier toward the outside, where the spacecraft is peering through haze, which washes out surface features.

The brighter region on the right side and equatorial region is named Xanadu Regio. Scientists are actively debating what processes may have created the bizarre surface brightness patterns seen here. The images hint at a young surface with no obvious craters. However, the exact nature of that activity, whether tectonic, wind-blown, fluvial, marine or volcanic is still to be determined.

The images comprising this mosaic were acquired from distances ranging from 650,000 kilometers (400,000 miles) to 300,000 kilometers (200,000 miles).

[BornAgainStar]

Cassini pierced the ring plane and rounded Saturn on Oct. 27, 2004, capturing this view of the dark portion of the rings. A portion of the planet's atmosphere is visible here, as is its shadow on the surface of the rings.
The image was taken with the Cassini spacecraft wide angle camera on Oct. 27, 2004, at a distance of about 618,000 kilometers (384,000 miles) from Saturn through a filter sensitive to wavelengths of infrared light centered at 1001 nanometers. The image scale is 33 kilometers (21 miles) per pixel.

This Cassini view of Enceladus hints at the curvilinear, groove-like features that crisscross the moon's surface, as seen in images from NASA's Voyager spacecraft.
The image shows the trailing hemisphere of Enceladus, which is the side opposite the moon's direction of motion in its orbit. Enceladus is 499 kilometers (310 miles) across.

The image was taken in visible light with the Cassini spacecraft narrow angle camera on Oct. 27, 2004, at a distance of about 766,000 kilometers (476,000 miles) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 34 degrees. The image scale is 4.6 kilometers (2.8 miles) per pixel.

[kattails2]

OMG these are fantastic! My dd is going to be so happy when she sees these tomorrow, they are studying the planets. Thanks for posting AM*

[BornAgainStar]

A gorgeous Dione poses for Cassini, with shadowed craters and bright, wispy streaks first observed by the Voyager spacecraft 24 years ago. The wispy areas will be imaged at higher resolution in mid-December 2004. Subtle variations in brightness across the surface of this moon are visible here as well. Dione's diameter is 1,118 kilometers, (695 miles).


The image shows primarily the trailing hemisphere of Dione, which is the side opposite the moon's direction of motion in its orbit. The image has been rotated so that north is up.


The image was taken in visible light with the Cassini spacecraft narrow angle camera on Oct. 27, 2004, at a distance of about 1.2 million kilometers (746,000 miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 28 degrees. The image scale is 3.5 kilometers (2.2 miles) per pixel.

[carloscai]

Hotter than the Florida high school teacher!

[BeckyAndKristinsMa]

Amazing....

[BornAgainStar]

Dark-stained Iapetus

This near-true color view from Cassini reveals the colorful and intriguing surface of Saturn's moon Iapetus in unrivaled clarity. The images taken with different spectral filters and used for this composite were taken at the same time as the clear frames used in PIA06166. The use of color on Iapetus is particularly helpful for discriminating between shadows (which appear black) and the intrinsically dark terrain (which appears brownish).
This image shows the northern part of the dark Cassini Regio and the transition zone to a brighter surface at high northern latitudes. Within the transition zone, the surface is stained by roughly north-south trending wispy streaks of dark material. The absence of an atmosphere on Iapetus means that the material was deposited by some means other than precipitation, such as ballistic placement from impacts occurring elsewhere on Iapetus, or was captured from elsewhere in the Saturn system. Iapetus's north pole is not visible here, nor is any part of the bright trailing hemisphere.

[HarleyD]

(CNN) -- The Huygens probe will plunge through the orange clouds of Saturn's moon Titan Friday, offering scientists their first glimpse of the mysterious moon.

"It's going to be the most exotic place we've ever seen," said Candice Hansen, a scientist for the Cassini-Huygens mission. "We've never landed on the surface of an icy satellite. We know from our pictures that there are very different kinds of geological processes."

If all goes well, the saucer-shaped Huygens will enter the thick atmosphere of Titan Friday at about 5:13 a.m. (ET). The data should start trickling in about five hours later.

The Cassini-Huygens mission is an unprecedented $3.3-billion effort between NASA, the European Space Agency and Italy's space program to study Saturn and its 33 known moons. The two vehicles were launched together from Florida in 1997.

"The mission is to explore the entire Saturnian system in considerably greater detail than we have ever been able to do before: the atmosphere, the internal structure, the satellites, the rings, the magnetosphere," said Cassini program manager Bob Mitchell at NASA.

The Huygens probe, about the size of a Volkswagen-Beetle, has been spinning silently toward Titan since it detached from the Cassini spacecraft on December 24. Cassini will remain in orbit around Saturn until at least July 2008.

"[The Cassini-Huygens mission] will probably help answer some of the big questions that NASA has in general about origins and where we came from and where life came from," said Mitchell.

Titan's atmosphere, a murky mix of nitrogen, methane and argon, resembles Earth's before life began more than 3.8 billion years ago. Scientists think the moon may shed light on how life evolved on Earth.

Finding living organisms, however, is a remote possibility. "It is not out of the question, but it is certainly not the first place I would look," said Hansen. "It's really very cold." A lack of sunlight has put Titan into a deep-freeze. Temperatures hover around -292 F (-180 C) making liquid water scarce and hindering chemical reactions needed for organic life.

New discoveries
The mysteries of Saturn, the sixth planet from the sun, have always enticed researchers. Scientists are perplexed why Saturn, a gas-giant composed primarily of hydrogen and helium, releases more energy than it absorbs from faint sunlight. Titan is also the only moon in the solar system to retain a substantial atmosphere, one even thicker than Earth's.

The 703-pound, battery-powered probe will parachute through Titan's clouds of methane and nitrogen for two and a half hours sampling gases and capturing panoramic pictures. Soon afterward, Huygens will reach the surface. However, its landing site is still a matter of conjecture. Scientists say it could be solid, slushy or even a liquid sea of ethane and hydrocarbons.

"Those are the kinds of things that we have theories about, but we really don't have data," said Hansen.

Huygens is expected to hit the upper atmosphere 789 miles (1,270 km) above the moon at a speed of about 13,700 mph (22,000 km/h). A series of three parachutes will slow the craft to just 15 mph (24 km/h). The chutes and special insulation will protect Huygens from temperature swings and violent air currents. Strong winds -- in excess of 311 mph (500 km/h) --will buffet the craft, at times dragging Huygens sideways after its parachute is deployed.

Sensors will deduce wind speed, atmospheric pressure and the conductivity of Titan's air. Methane clouds and possibly hydrocarbon rain can be analyzed by an onboard gas chromatograph. A microphone will listen for thunder.

Three rotating cameras will snap panoramic views of the moon capturing up to 1,100 images. A radar altimeter will map Titan's topography and a special lamp will illuminate the probe's landing spot to help determine the surface composition.

Engineers say they are confident that Huygens and its suite of six sensitive instruments will survive the descent.

"From an engineering standpoint, I'm very confident in a positive outcome," said Shaun Standley, an ESA systems engineer for Huygens at the Jet Propulsion Laboratory in California. "We've been over this again and again for the last three years fine-tuning this."

As the largest and most sophisticated interplanetary vehicle ever launched, according to NASA, Cassini-Huygens has performed well on its 2.2-billion mile (3.5 billion km) journey.

Cassini crossed Saturn's rings without mishap in June 2004 and produced the most revealing photos yet of the rings and massive gas-giant. A problem with the design of an antennae on Cassini almost scrapped Huygens' mission, but engineers altered the spacecrafts' flight plans to resolve the transmission problem.

Now, Huygens is on its own.

Controllers can only that hope years of preparation will pay off. "[Huygens] is on its way, we can't contact it," said Standley. "We can't make any changes of anything that is on board. [It's] just waiting for the right moment."

[HarleyD]

Huygens has arrived.

The probe landed on the surface of Saturn's moon Titan this morning around 7:45 ET, reported elated scientists from the European Space Agency, who are eagerly awaiting data about the cloud-shrouded moon.

"We have a signal. We know that Huygens is alive meaning the dream is alive," said Jean-Jacques Dordain director general for ESA which designed Huygens. "This is already an engineering success and we will see, later this afternoon, if this is a scientific success."

Grinning scientists watching from the ESA operations center in Germany said the first obstacle -- a tricky atmospheric entry -- had been a great engineering feat. Time will tell if all of Huygens' precious data will reach Earth. The probe will continue sending data until its batteries run out or Cassini, the satellite orbiting Saturn relaying Huygens' signal, passes over the moon's horizon in about two hours' time.

"So far so good," said David Southwood, director of science for ESA. "The signal has been solid for a long time."

The saucer-shaped probe is completing the final hours of its 2.2 billion-mile mission to study the icy world. It plunged through the orange clouds of Saturn's moon Titan early Friday morning deploying three parachutes to slow down from a blistering reentry speed.

Jean-Pierre Lebreton, Huygens project scientist, said the first data from a Doppler wind experiment were reaching Earth and more data would arrive throughout the morning. Radio telescopes around the world are tracking Huygens' signal.

When the first images arrive this afternoon, scientists will have their long-anticipated glimpse at an alien world.

"It's going to be the most exotic place we've ever seen," said Candice Hansen, a scientist for the Cassini-Huygens mission. "We've never landed on the surface of an icy satellite. We know from our pictures that there are very different kinds of geological processes."

The Cassini-Huygens mission is an unprecedented $3.3-billion effort between NASA, the European Space Agency and Italy's space program to study Saturn and its 33 known moons. The two vehicles were launched together from Florida in 1997.

"The mission is to explore the entire Saturnian system in considerably greater detail than we have ever been able to do before: the atmosphere, the internal structure, the satellites, the rings, the magnetosphere," said Cassini program manager Bob Mitchell at NASA.

The Huygens probe, about the size of a Volkswagen Beetle, has been spinning silently toward Titan since it detached from the Cassini spacecraft on December 24. Cassini will remain in orbit around Saturn until at least July 2008.

The mission "will probably help answer some of the big questions that NASA has in general about origins and where we came from and where life came from," Mitchell said.

Titan's atmosphere, a murky mix of nitrogen, methane and argon, resembles Earth's more than 3.8 billion years ago. Scientists think the moon may shed light on how life began.

Finding living organisms, however, is a remote possibility. "It is not out of the question, but it is certainly not the first place I would look," Hansen said. "It's really very cold." A lack of sunlight has put Titan into a deep-freeze. Temperatures hover around -292 F (-180 C) making liquid water scarce and hindering chemical reactions needed for organic life.

New discoveries
The mysteries of Saturn, the sixth planet from the sun, have always enticed researchers. Scientists are perplexed why Saturn, a gas-giant composed primarily of hydrogen and helium, releases more energy than it absorbs from faint sunlight. Titan is also the only moon in the solar system to retain a substantial atmosphere, one even thicker than Earth's.

The 703-pound, battery-powered Huygens probe parachuted through Titan's clouds of methane and nitrogen for two-and-a-half hours, sampling gases and capturing panoramic pictures along the way.

Huygens hit the upper atmosphere 789 miles (1,270 km) above the moon at a speed of about 13,700 mph (22,000 km/h). A series of three parachutes slowed the craft to just 15 mph (24 km/h). Chutes and special insulation protect Huygens from temperature swings and violent air currents. Strong winds -- in excess of 311 mph (500 km/h) -- buffeted the craft, capable of dragging Huygens sideways after its parachute was deployed.

Its sensors can deduce wind speed, atmospheric pressure and the conductivity of Titan's air. Methane clouds and possibly hydrocarbon rain will be analyzed by an onboard gas chromatograph. A microphone will listen for thunder.

Three rotating cameras are snapping panoramic views of the moon, capturing up to 1,100 images. A radar altimeter is mapping Titan's topography and a special lamp illuminated the probe's landing spot to help determine the surface composition.

Engineers were confident that Huygens and its suite of six sensitive instruments would survive the descent.

"From an engineering standpoint, I'm very confident in a positive outcome," said Shaun Standley, an ESA systems engineer for Huygens at the Jet Propulsion Laboratory in California. "We've been over this again and again for the last three years fine-tuning this."

Cassini crossed Saturn's rings without mishap in June 2004 and produced the most revealing photos yet of the rings and massive gas-giant. A problem with the design of an antennae on Cassini almost scrapped Huygens' mission, but engineers altered the spacecrafts' flight plans to resolve the transmission problem.

[BornAgainStar]

Mimas drifts along in its orbit against the azure backdrop of Saturn's northern latitudes in this true color view from NASA's Cassini spacecraft. The long, dark lines on the atmosphere are shadows cast by the planet's rings.

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.