With other words; don't light any matches!

Outbound View
August 18, 2006

This remarkably clear view from that flyby shows the moon's characteristically dark mid-latitudes, and more southern terrain than the Cassini spacecraft has usually been able to glimpse.
This was the first in a series of "illuminated outbound flybys" of Titan (5,150 kilometers, or 3,200 miles across) where the illuminated hemisphere was visible following the closest approach. Cassini's flyby of Titan on July 22, 2006 sent the spacecraft into a more inclined orbit about Saturn.

The image was taken in polarized infrared light with the Cassini spacecraft wide-angle camera on July 22, 2006 at a distance of approximately 148,000 kilometers (92,000 miles) from Titan. Image scale is 9 kilometers (5 miles) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

Credit: NASA/JPL/Space Science Institute

Source: NASA/JPL - Cassini

Swimming in Dunes
September 12, 2006

This image from Cassini's radar instrument was acquired by the Cassini radar instrument in synthetic aperture mode during a Sept. 7, 2006, flyby of Titan.
The image shows long, dark ridges similar to those seen in previous flybys. These are interpreted to be longitudinal dunes. Dunes are mostly an equatorial phenomenon on Titan, and the material forming them may be solid organic particles or ice coated with organic material. Spaced up to 3 kilometers (about 2 miles) apart, these dunes curve around bright features that may be high-standing topographic obstacles, in conformity with the wind patterns. The interaction between the two types of features is complex and not well understood, but clearly the topography and the dunes have influenced each other in other ways as well.

This image is centered at 44 degrees west longitude, 8 degrees north latitude and covers approximately 160 by 325 kilometers (99 by 202 miles) on Titan's surface. The smallest details in this image are about 500 meters (about 550 yards) across.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

Credit: NASA/JPL

Source: NASA/JPL - Cassini

Crater Studies on Titan
September 12, 2006

This image from Cassini's radar instrument shows an impact crater with a diameter of 30 kilometers (19 miles) on the surface of Saturn's moon Titan.
Cassini data have only revealed three definite impact craters on Titan so far, so each new discovery adds significantly to our body of knowledge. Impact craters are particularly important, as their shapes give scientists insight into the structure of the crust beneath Titan's surface. The difference in overall appearance between this crater, which has a central peak, and those without, such as Sinlap, (See Impact Crater with Ejecta Blanket), indicates variations in the conditions of impact, thickness of the crust, or properties of the meteorite that made the crater. The dark floor indicates smooth or highly absorbing materials.

This image was acquired by the Cassini radar instrument in synthetic aperture mode during a Sept. 7, 2006, flyby of Titan. The image is centered at 70 degrees west longitude, 10 degrees north latitude, and measures about 150 kilometers high by 190 kilometers wide (93 by 118 miles). The smallest details in this image are about 500 meters (about 550 yards) across.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

Credit: NASA/JPL

Source: NASA/JPL - Cassini

As always no expert here.

Whereas I admit a 19 mile crator is a colossal feature on the surface, I am somewhat confused why it has not been filled by the migrating sand dunes which appear present in the picture.

My only idea is that the surface of Titan is solid with a sand layer that migrates round the moon. The crater forms in the solid part and sand enters and leaves at a constant volume.

Am I seeing something or???

The University of of Arizona press release is reproduced below:


The Visual and Infrared Mapping Spectrometer (VIMS) on NASA's
Cassini spacecraft recorded these infrared images of Titan's northern
hemisphere. Image (A) was taken on Dec. 13, 2004; image (B ) on
Aug. 22, 2005; image © on Aug. 21, 2005; and image (D) on
Sept. 7, 2005. The images show the reflection of sunlight on Titan's
atmosphere at 2.8 microns, which are longer wavelengths than human
eyes can detect. The image appears in false color so that the highest
reflection appears as a reddish hue. The vast cloud can be seen in all
images as a reddish band just north of 50 degrees latitude. The top
of the image in panel D also shows a strong reflection off the limb of
the planet (also reddish) which is caused by the lighting angle and
does not indicate the presence of clouds.
(Photo: NASA/JPL/University of Arizona)

By Lori Stiles
September 14, 2006

Cassini's Visual and Infrared Mapping Spectrometer (VIMS) has detected what appears to be a massive ethane cloud surrounding Titan's north pole. The cloud might be snowing ethane snowflakes into methane lakes below.

The cloud may be the clue needed in solving a puzzle that has confounded scientists who so far have seen little evidence of a veil of ethane clouds and surface liquids originally thought extensive enough to cover the entire surface of Titan with a 300-meter-deep ocean.

Before the Cassini-Huygens mission began visiting Titan in 2004, "We expected to see lots of ethane -- vast ethane clouds at all latitudes and extensive seas on the surface of Saturn's giant moon Titan," University of Arizona planetary scientist Caitlin Griffith said.

That's because solar ultraviolet light irreversibly breaks down methane in Titan's mostly nitrogen atmosphere. Ethane is by far the most plentiful byproduct when methane breaks down. If methane has been a constituent of the atmosphere throughout Titan's 4.5-billion-year lifetime -- and there was no reason to suspect it had not -- the large moon would be awash with seas of ethane, scientists theorized.

NASA's Cassini spacecraft radar found lakes in Titan's north arctic latitudes on a flyby last July 22. However, "We now know that Titan's surface is largely devoid of lakes and oceans," Griffith said. She is a member of the UA-based Cassini VIMS team, headed by Professor Robert Brown of UA's Lunar and Planetary Lab.

The missing ethane is all the more mysterious because Cassini images suggest that other less abundant solid precipitates from the photochemical reactions in Titan's atmosphere have formed dunes and covered craters on its surface, Griffith said.

VIMS made the first detection of Titan's vast polar ethane cloud when it probed Titan's high northern latitudes on Cassini flybys in December 2004, August 2005, and September 2005.

VIMS detected the cirrus cloud as a bright band at altitudes from between 30 km and 60 km at the edge of Titan's arctic circle, between 51 degrees and 69 degrees north latitude. VIMS saw only part of the cloud because most of the northern polar region is in winter's shadow and won't be fully illuminated until 2010, Griffith noted.

"Our observations imply that surface deposits of ethane should be found specifically at the poles, rather than globally distributed across Titan's disk as previously assumed," Griffith said. "That may partially explain the lack of liquid ethane oceans and clouds at Titan's middle and lower latitudes."

"We think that ethane is raining or, if temperatures are cool enough, snowing on the north pole right now. When the seasons switch, we expect ethane to condense at the south pole during its winter," Griffith said. If polar conditions are as cool as predictions say, ethane could accumulate as polar ice.

Ethane dissolves in methane, which scientists predict is raining from the atmosphere at the north pole during its cool winter. "During the polar winters, we expect the lowlands to cradle methane lakes that are rich with ethane," Griffith noted. "Perhaps these are the lakes recently imaged by Cassini."

If ethane was produced at today's rate over Titan's entire lifetime, a total of two kilometers of ethane would have precipitated over the poles. But that seems unlikely, Griffith said.

Scientists have no direct evidence for polar caps of ethane ice. Titan's north pole is in winter darkness, and Cassini cameras have yet to see it in reflected light. Cassini cameras have imaged Titan's south pole. "The morphology seen in those images doesn't suggest a two kilometer polar ice cap, but the images do show flow features," Griffith said.

"We're going to start making more polar passes in the upcoming months," she added. "By the end of next year Cassini will have recorded the first polar temperature profile of Titan, which will tell us how cold conditions are at the pole."

Griffith is first author on the article, "Evidence for a Polar Ethane Cloud on Titan," published in the current (Sept.15) issue of Science. Paulo Pinteado and VIMS team leader Robert Brown of the UA and researchers from France, the Jet Propulsion Laboratory in Pasadena, Calif., the U.S. Geological Survey, Cornell University, NASA Ames Research Center, Portugal and Germany are co-authors.

Griffith, Pinteado and Robert Kursinski of UA collaborated earlier in studies of the thousand-mile-long methane clouds that band Titan at southern latitudes. They concluded from analyzing VIMS images that these highly localized, convective clouds, which are composed of methane, result from summer heating much as thunderstorms form on Earth.

The VIMS instrument is an imaging spectrometer that produces a special data set called an image cube. It takes an image of an object in many colors simultaneously. An ordinary video camera takes images in three primary colors (red, green, and blue) and combines them to produce images as seen by the human eye. The VIMS instrument takes images in 352 separate wavelengths, or colors, spanning a realm of colors far beyond those visible to humans. All materials reflect light in a unique way. So molecules of any element or compound can be identified by the wavelengths they reflect or absorb, their "signature" spectra.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The Visual and Infrared Mapping Spectrometer team is based at The University of Arizona in Tucson.

Source: UA Press Release

See also: This post in the Cassini - Infrared Images thread

Titan's Halo
September 21, 2006

Titan's murky atmosphere shines as a halo of scattered light.
Prior to the Cassini spacecraft's arrival, Titan remained incognito, swathed in its impenetrable envelope of frigid gases. Now, gradually but relentlessly, the veil continues to fall away under Cassini's gaze, bringing the wonders of this world into view.

North on Titan (5,150 kilometers, or 3,200 miles across) is up.

The image was taken using a spectral filter sensitive to wavelengths of infrared light centered at 938 nanometers. The image was acquired with the Cassini spacecraft narrow-angle camera on Aug. 10, 2006 at a distance of approximately 3.1 million kilometers (1.9 million miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 165 degrees. Image scale is 18 kilometers (11 miles) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

Credit: NASA/JPL/Space Science Institute

Source: NASA/JPL - Cassini

Titan's "Kissing Lakes"
September 26, 2006

This Cassini radar image shows two lakes "kissing" each other on the surface of Saturn's moon Titan.
The image from a flyby on Sept. 23, 2006, covers an area about 60 kilometers (37 miles) wide by 40 kilometers (25 miles) high.

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.

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.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit
http://saturn.jpl.nasa.gov.

Credit: NASA/JPL

Source: NASA/JPL - Cassini

Shorefront Property, Anyone?
September 26, 2006

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.

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.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit
http://saturn.jpl.nasa.gov.

Credit: NASA/JPL

Source: NASA/JPL - Cassini

Titan's Great Lakes?
October 12, 2006

Using its radar system, the Cassini spacecraft has imaged new lakes on Titan.
The large dark patch seen on this image, at high latitudes surrounding Titan's north pole, is most likely a hydrocarbon lake. Several dark channels can be seen; the longest one at the left meanders over almost 100 kilometers (62 miles), and appears to drain into the lake. Some dark channels are remarkably straight, suggesting possible faulting in the subsurface. The bright landforms jutting into the lake indicate that old, eroded landforms may have flooded. For a different radar view from the same flyby see Lakes and more lakes.

This radar image was acquired by the Cassini radar instrument in synthetic aperture mode on Oct. 9, 2006. The image is centered near 73 degrees north latitude, 343 degrees west longitude, and measures about 300 kilometers by 140 kilometers (190 miles by 90 miles). Smallest details in this image are about 500 meters (1,640 feet) across.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov.

Credit: NASA/JPL

Source: NASA/JPL - Cassini

Lakes and More lakes
October 12, 2006

In this image taken by the Cassini radar system, a previously unseen style of lakes is revealed. The lakes here assume complex shapes and are among the darkest seen so far on Titan.
The lake at the left is reminiscent both in form and scale of the flooded drainage system, Lake Powell in Utah and Arizona. However, the Titan lake has been filled with liquid methane and ethane rather than water. In the lake at right, older terrain may have been deeply cut by river valleys before it was flooded by the embaying lake. For a different radar view from the same flyby see Titan's Great Lakes? .

This radar image was acquired Oct. 9, 2006, and is centered near 80 degrees north latitude, 357 degrees west longitude. It measures about 310 kilometers by 100 kilometers (190 miles by 62 miles). Smallest details in this image are about 500 meters (1,640 feet) across.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov.

Credit: NASA/JPL

Source: NASA/JPL - Cassini

I've only ever heard of hydrocarbons being developed from decomposing biological matter, so which process resulted in the formation of these lakes, especially in such large amounts?

Hydrocarbons include some very simple molecules like methane (CH4) and ethane (C2H6) as well as the complex hydrocarbons like oil.

These simple hydrocarbons can be formed quite easily where there is hydrogen and carbon dioxide and an input of energy. In nature this energy can be sunlight (particularly UV). This photochemical process produces hydrocarbon aerosols in the atmosphere of the gas giant planets and is responsible for the methane and ethane found on Titan.

I see, interesting. Thanks.



Lucky there isn't any oxygen, or a single spark and there'd be a giant ball of fire orbiting Saturn.

Such a fascinating climate.

December 12, 2006
(Source: Jet Propulsion Laboratory)

The tallest mountains ever seen on Titan -- coated with layers of organic material and blanketed by clouds -- have been imaged on Saturn's moon Titan by NASA's Cassini spacecraft.


This composite image shows a massive
mountain range running just south of Titan's
equator.

"We see a massive mountain range that kind of reminds me of the Sierra Nevada mountains in the western United States. This mountain range is continuous and is nearly 100 miles long," said Dr. Bob Brown, team leader of the Cassini visual and infrared mapping spectrometer at the University of Arizona, Tucson.

During an Oct. 25 flyby designed to obtain the highest resolution infrared views of Titan yet, Cassini resolved surface features as small as 400 meters (1,300 feet). The images reveal a large mountain range, dunes, and a deposit of material that resembles a volcanic flow. These data, together with radar data from previous flybys, provide new information on the height and composition of geologic features on Titan.


Exposing Titan's Surface

If Titan were Earth, these mountains would lie south of the equator, somewhere in New Zealand. The range is about 150 kilometers long (93 miles) and 30 kilometers (19 miles) wide and about 1.5 kilometers (nearly a mile) high. Deposits of bright, white material, which may be methane "snow" or exposures of some other organic material, lie at the top of the mountain ridges.

"These mountains are probably as hard as rock, made of icy materials, and are coated with different layers of organics," said Dr. Larry Soderblom, Cassini interdisciplinary scientist at the U.S. Geological Survey, Flagstaff, Ariz.

He added, "There seem to be layers and layers of various coats of organic 'paint' on top of each other on these mountain tops, almost like a painter laying the background on a canvas. Some of this organic gunk falls out of the atmosphere as rain, dust, or smog onto the valley floors and mountain tops, which are coated with dark spots that appear to be brushed, washed, scoured and moved around the surface."


Infrared and Radar Views of Titan

The mountains probably formed when material welled up from below to fill the gaps opened when tectonic plates pull apart, similar to the way mid-ocean ridges are formed on Earth.

Separately, the radar and infrared data are difficult to interpret, but together they are a powerful combination. In the infrared images, one can see the shadows of the mountains, and in radar, one can see their shape. But when combined, scientists begin to see variations on the mountains, which is essential to unraveling the mysteries of the geologic processes on Titan.

A fan-shaped feature, possibly a remnant of a volcanic flow, is also visible in the infrared images. The radar instrument imaged this flow and a circular feature from which the flow seems to emanate on a previous flyby, but not in this level of detail.


Image composite containing a radar image,
overlaid with images from the visual and
infrared mapping spectrometer

"The evidence is mounting that this circular feature is a volcano," said Dr. Rosaly Lopes, Cassini radar team member at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "With radar data alone, we identified it as a possible volcano, but the combination of radar and infrared makes it much clearer."

Near the wrinkled, mountainous terrain are clouds in Titan's southern mid latitudes whose source continues to elude scientists. These clouds are probably methane droplets that may form when the atmosphere on Titan cools as it is pushed over the mountains by winds.

The composition of dunes that run across much of Titan is also much clearer. "The dunes seem to consist of sand grains made of organics, built on water-ice bedrock, and there may also be some snow and bright deposits," Brown said.


Two views of an area riddled by mountain
ranges that were probably produced by
tectonic forces.

Titan is a complex place and scientists are uncovering the secrets of the surface, one flyby at a time. Scientists hope to get more clues from the next Titan flyby, on Dec. 12.

For the new infrared images of the mountains visit: http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov and http://wwwvims.lpl.arizona.edu. Additional information on NASA news from the American Geophysical Union conference is at http://www.nasa.gov/agu.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.

Contacts:
Carolina Martinez 818-354-9382
Jet Propulsion Laboratory, Pasadena, Calif.

NEWS RELEASE: 2006-147

Source: NASA/JPL - Cassini - Press Release

---------------------------------------------

Larger versions of these images, with more explanation can be found in the Cassini - Infrared Images thread, starting with THIS POST.

Peeking at Saturn
December 29, 2006

Cassini peers around the hazy limb of Titan to spy the sunlit south pole of Saturn in the distance beyond. The thick, smog-like atmosphere of frigid Titan is a major source of interest for the Cassini mission. The moon is 5,150 kilometers (3,200 miles) across.

Images taken using red, green and blue spectral filters were combined to create this natural-color view. The image was taken with the Cassini spacecraft narrow-angle camera on Dec. 26, 2005, at a distance of approximately 26,000 kilometers (16,000 miles) from Titan. Image scale is 1 kilometer (4,643 feet) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA\'s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

Credit: NASA/JPL/Space Science Institute

Source: NASA/JPL - Cassini

Improving the View of Titan
December 29, 2006

As Cassini continues its reconnoitering flybys of Titan, the imaging science team continues to improve its ability to tease out surface details hidden in the unprocessed images. This mosaic provides the best view yet obtained by Cassini's cameras, showing terrain on the moon's sub-Saturn hemisphere -- the side of the moon that always faces toward Saturn.

This mosaic has better resolution, both in pixel scale and from improved signal-to-noise, compared to previous views of the area. "Signal-to-noise" is a term scientists use to refer to the amount of meaningful or useful information (signal) in their data versus the amount of background noise. A higher signal-to-noise ratio yields sharper, clearer views of Titan's surface.

The view is centered on terrain in the Fensal-Aztlan region on Titan, at 0.03 degrees south latitude, 22.18 degrees west longitude. The mosaic covers an area 3,500 kilometers (2,180 miles) north to south and 3,600 kilometers (2,240 miles) west to east. North is up.

The mosaic consists of 17 frames taken using a spectral filter sensitive to wavelengths of infrared light centered at 938 nanometers. Each frame was created by combining and specially processing four individual images of the same region of Titan's surface. The frames were then sharpened to improve visibility of surface features.

The images in this mosaic were taken using the Cassini spacecraft narrow-angle camera at distances ranging from 81,200 to 119,500 kilometers (50,500 to 74,300 miles) and at a sun-Titan-spacecraft, or phase, angle of about 25 degrees. The original image scale ranged from 470 to 700 meters (1,540 to 2,300 feet) per pixel. Because the actual resolution on Titan is a few times the pixel scale, this orthographic projection mosaic was scaled to 1 kilometer (0.6 mile) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA\'s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

Credit: NASA/JPL/Space Science Institute

Source: NASA/JPL - Cassini

January 03, 2007

Scientists report definitive evidence of the presence of lakes filled with liquid methane on Saturn's moon Titan in this week's journal Nature cover story.

Radar imaging data from a July 22, 2006, flyby provide convincing evidence for large bodies of liquid on Titan today. A new false-color radar view gives a taste of what Cassini saw. Some highlights of the article follow below.


This colorized radar view from Cassini shows
lakes on Titan. Color intensity is proportional
to how much radar brightness is returned.
The colors are not a representation of what
the human eye would see.
Image credit: NASA/JPL/USGS
+ Full image and caption
+ Larger image


Radar view of lake on Titan.
Image credit: NASA/JPL
+ Full image and caption
+ Larger image

Lake Characteristics:

-Radar-dark patches are interpreted as lakes based on their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions.

-Radar-dark surfaces are smooth and most likely liquid, rock, ice or organics. More than 75 radar-dark patches or lakes were seen, ranging from 3 kilometers (1.8 miles) to more than 70 kilometers (43 miles) across.

-Some lakes appear partly dry, while others seem liquid-filled. Some of the partly filled lakes may never have filled fully, or may have partly evaporated at some point in the past. The dry lakes have margins or rims and a radar brightness similar to the rest of the surrounding terrain, making them appear devoid of liquid.

-The varying states of how full the lakes are suggest that lakes in this region of Titan might be temporary on some unknown timescale.

-Approximately 15 of the dark patches seem filled and show no clear evidence of erosion. These dark patches resemble terrestrial lakes confined within impact basins (for example, Clearwater Lakes in Canada) or within volcanic calderas (for example, Crater Lake, Oregon). The nest-like nature of these lakes and their limited range of sizes make it unlikely that they originated from an impact. A volcanic origin for the depressions is possible, given their appearance.

-Some lakes have steep margins and very distinct edges, suggesting a topographic rim. These lakes are consistent with seepage or groundwater drainage lakes.

-Other lakes have diffuse, more scalloped edges, with a gradual decrease in radar brightness towards the center of the lake. These lakes are more likely to be associated with channels, and may be either drainage lakes or groundwater drainage lakes.

-Yet other lakes have curvy channel-like extensions, similar in appearance to terrestrial flooded river valleys (for example Lake Powell).

-Bright patches near the lake edges could be small islands peeking through the surface. Floating “icebergs” are unlikely because most materials would not float in liquid hydrocarbons.

Other Observations:

-Based on the lake characteristics, Cassini scientists think they are observing liquid-filled lakes on Titan today. Another possibility is that these depressions and channels formed in the past and have now been filled by a low-density deposit that is darker than any observed elsewhere on Titan. However, the absence of wind-blown features in this area makes the low-density hypothesis unlikely.

-These northern hemisphere lakes are the strongest evidence yet that Titan's surface and atmosphere have an active hydrological cycle, though with a condensable liquid other than water. In this cycle, lakes are filled through methane rainfall or intersect with a subsurface layer saturated with liquid methane.

-As Titan's seasons progress over the 29-year cycle of Saturn's orbit around the sun, lakes in the winter hemisphere should expand by steady methane rain, while summer hemisphere lakes shrink or dry up entirely.

To read more about the radar imaging data from the July 2006 flyby, go to Cassini Finds Lakes on Titan's Arctic Region.

Media contact: Carolina Martinez/JPL
818-354-9382

Related Links:
+ Podcast: Lakes on Titan
+ Related audio clips
+ Related release: Cassini Finds Lakes on Titan's Arctic Region (July 27, 2006)
+ Cassini home page

Source: NASA/JPL - Feature Stories

Liquid Lakes on Titan
January 3, 2007

The existence of oceans or lakes of liquid methane on Saturn's moon Titan was predicted more than 20 years ago. But with a dense haze preventing a closer look it has not been possible to confirm their presence. Until the Cassini flyby of July 22, 2006, that is.

Radar imaging data from the flyby, published this week in the journal Nature, provide convincing evidence for large bodies of liquid. This image, used on the journal's cover, gives a taste of what Cassini saw. Intensity in this colorized image is proportional to how much radar brightness is returned, or more specifically, the logarithm of the radar backscatter cross-section. The colors are not a representation of what the human eye would see.

The lakes, darker than the surrounding terrain, are emphasized here by tinting regions of low backscatter in blue. Radar-brighter regions are shown in tan. The strip of radar imagery is foreshortened to simulate an oblique view of the highest latitude region, seen from a point to its west.

This radar image was acquired by the Cassini radar instrument in synthetic aperture mode on July 22, 2006. The image is centered near 80 degrees north, 35 degrees west and is about 140 kilometers (84 miles) across. Smallest details in this image are about 500 meters (1,640 feet) across. .

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm .

Credit: NASA/JPL/USGS

Source: NASA/JPL - Cassini

I wonder if it's really as gorgeous as the artist's rendering; if so, what I wouldn't give to go there...securely enclosed in an appropriate suit along with some oxygen, of course.

Two Sides of Dunes
January 11, 2007
This pair of images, taken by the Cassini spacecraft radar mapper on two different Titan passes on Dec. 11, 2006 (T21 left), and Oct. 29, 2005 (T8 right), represent two different views of a field of dunes located near 9.4 degrees south latitude by 290 degrees west longitude.

The images were taken in synthetic aperture mode and have a resolution of approximately 500 meters (1,640 feet). North is toward the top of both images, and each image is approximately 400 kilometers (250 miles) long by 275 kilometers (170 miles) wide. The images are different only because the radar instrument illuminated the dunes from different directions. Acting somewhat like a flash camera, the radar sends out microwave pulses and makes an image from the pulses after they are reflected back. Imagine that both the ¿camera¿ and the ¿flash¿ come from the left in the left image and from the top in the right image.

Most obvious differences are seen in the large bright feature at the center of both images. At left, its left edge is brighter, emphasizing the more steep slopes there. Farther left, the dunes are more clearly defined in the right image as their faces are caught by the illumination. However, since the dunes are visible in both images, it is likely that the materials making up the dark and light stripes are also somehow different. More detailed studies of how materials on Titan reflect and scatter at different angles are giving us clues about what different materials might be present in this cold and distant world.

For more information about dunes on Titan, see Dunes Galore.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm.

Credit: NASA/JPL

Source: NASA/JPL - Cassini

Titan (T16) Viewed by Cassini's Radar July 22, 2006
January 11, 2007

This radar image shows the entire scene in which hydrocarbon lakes were first discovered on Titan, near its north pole (see Lakes on Titan). This image was acquired on July 22, 2006, by Cassini's radar instrument in synthetic aperture mode.

The most striking landforms are the lakes: dark patches, some circular, some irregular, many with apparently steep rims, over much of the terrain north of 70 degrees latitude. The most convincing lake forms occur at the narrowest, central part of the scene, which is at the highest latitudes. Here they have short, stubby channels leading into them, and brighter areas within that indicate either dried-up lakes or that we are seeing through a transparent liquid.

The image also shows the considerable variation in the kinds of surface features found at different latitudes. Beginning at the left (20 degrees north by 142 degrees west) and heading north, a circular feature about 75 kilometers (47 miles) in diameter is seen, which could be either an impact crater or a volcanic caldera. Other less distinct circular forms are seen next, possibly including some dried lakes, followed by some ridge-like terrain with dark meandering channels or valleys. The dark lakes begin to appear next (at about 70 degrees north), with more distinct lakes in the middle of the scene, where the swath is closest to the pole and starts to descend to the south. Farther on, apparently dry lakes and canyons begin to dominate, and the region becomes more complex and etched. At the extreme right end, dunes similar to those seen previously mingle with brighter features. The swath ends at 13 degrees north by 347 degrees west.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm.

Credit: NASA/JPL

Source: NASA/JPL - Cassini

12 January 2007
Two years ago, planetary scientists across the world watched as Europe and the US did something amazing. The Huygens descent module drifted down through the hazy atmosphere of Saturn's moon Titan, beaming its data back to Earth via the Cassini mothership. Today, Huygens's data are still continuing to surprise researchers.

Titan holds a unique place in the Solar System. It is the only moon covered in a significant atmosphere. The atmosphere has long intrigued scientists as it may be similar to that of the early Earth but the deeper mystery was: what lies beneath the haze?


Images recorded by the Huygens DISR between 17 and 8 km were assembled to produce this panoramic mosaic. The probe groundtrack is indicated as points; north is up. Narrow dark linear markings, interpreted as channels, cut through the brighter terrain. The complex channel network implies precipitation (likely as methane ‘rain’) and possibly springs. The circle indicates the outline of the low-altitude panorama view from 1.2 km below (3rd image in article).

Credits: ESA/NASA/Univ. of Arizona

The European Space Agency built the Huygens spacecraft to find out. The probe, carrying scientific investigations involving both sides of the Atlantic, hitched a ride on NASA's Cassini spacecraft. Together Cassini and Huygens make an unprecedented joint space mission - as a major milestone, Huygens parachuted to the surface of Titan on 14 January 2005.

While Cassini keeps flying by this moon of Saturn collecting new amazing data, one can say that the data collected by Huygens’s six instruments during its 2.5-hour descent and touch-down have provided the most spectacular view of this world yet and first dramatic change in the way we now think about it.

"When you put all the data together, we get a very rich picture of Titan," says Athéna Coustenis, Observatoire de Paris, France, "The Descent Imager/Spectral Radiometer (DISR) pictures were an enormous surprise. We had expected a much smoother landscape." Instead, they saw a varied landscape of channels that had been formed by some kind of flowing liquid.


This image of Titan’s surface was taken on 14 January 2005 by the Descent Imager/Spectral Radiometer (DISR) on board ESA’s Huygens mission, after touch-down. When printed on letter sized paper, the image shows the size of Titan’s pebbles in their true size.

Credits: ESA/NASA/JPL/University of Arizona

"At the landing site we also saw rounded ice pebbles," says Jonathan Lunine, University of Arizona. The Surface Science Package (SSP) provided the final piece in this particular puzzle. The impact it detected when Huygens touched down indicated that the spacecraft had come to rest in compacted gravel. "Put it all together and it is clear that Huygens landed in an outflow wash," says Lunine.

The Gas Chromatograph and Mass Spectrometer (GCMS) instrument confirmed the nature of the liquid that shapes the surface of Titan. It detected methane evaporating from the Huygens landing site. "Methane on Titan plays the role that water plays on Earth," concludes Lunine. But there are still mysteries. It is not yet clear whether the methane falls mostly as a steady drizzle or as an occasional deluge.

The GCMS also detected two isotopes of argon. Both have important stories to tell. The Ar40 indicates that the interior of Titan is still active. This is unusual in a moon and indicates that perhaps an insulating layer of water ice and methane is buried in the moon itself, close to the surface, trapping the heat inside it. Occasionally, this heat causes the so-called cryo-volcanoes to erupt. Icy 'lava' flows from these cryo-volcanoes have been seen from the orbiting Cassini spacecraft. Because Ar40 is so heavy, it is mostly concentrated towards the base of the atmosphere, so having Huygens on the surface was essential for its detection.

Daniel Gautier, Observatoire de Paris, France, thinks that the other isotope, Ar36, is telling scientists that Titan formed after Saturn, at a time when the primeval gas cloud that became the Solar System had cooled to about 40 ºK (-233 ºC).


Artist's impression of the descent and landing sequence followed by ESA''s Huygens probe to Titan.

Credits: ESA - C. Carreau

The atmosphere of Titan held surprises too. "Huygens made a fantastic and unexpected discovery about the wind," says Gautier. At an altitude of around 60 kilometres, the wind speed dropped, essentially to zero. Explaining this behaviour presents a challenge for theoreticians who are developing computer models of the moon’s atmospheric circulation.

The Huygens Atmosphere Structure Instrument (HASI) provided the temperature of the atmosphere from 1600 kilometres altitude down to the surface. "This has helped put all the other data into context," says Coustenis. Huygens measured the composition profile of the atmosphere to be a mixture of nitrogen, methane and ethane. The methane and ethane provide humidity, as water does in Earth’s atmosphere. At the surface of Titan, Huygens measured the temperature to be 94 ºK (-179 ºC) with a humidity of 45 percent.


The existence of oceans or lakes of liquid methane on Saturn's moon Titan was predicted more than 20 years ago. But with a dense haze preventing a closer look it has not been possible to confirm their presence. Until the Cassini flyby of 22 July 2006, that is.

Radar imaging data from the Cassini flyby of Titan provide convincing evidence for large bodies of liquid. This image gives a taste of what Cassini saw. Intensity in this colorized image is proportional to how much radar brightness is returned, or more specifically, the logarithm of the radar backscatter cross-section. The colors are not a representation of what the human eye would see.

The lakes, darker than the surrounding terrain, are emphasized here by tinting regions of low backscatter in blue. Radar-brighter regions are shown in tan. The strip of radar imagery is foreshortened to simulate an oblique view of the highest latitude region, seen from a point to its west.

Credits: NASA/JPL/USGS

Even though the Huygens data set is now two years old, the discoveries have not yet stopped. "There are lots of surprises still to come from this data," says Francesca Ferri, Università degli Studi di Padova. In addition, Huygens gives planetary scientists a wealth of 'ground-truth' to complement and help interpret the observations still coming from Cassini. At the beginning of 2007, Cassini showed that liquid methane is present on Titan in lakes.

Cassini, whose experiments also see a joint US and European participation, will make another 22 fly-bys of Titan - the first on 13 January - between now and the end of its scheduled mission in the summer of 2008. The Cassini-Huygens scientists are discussing their options to extend the mission. One idea, says Christophe Sotin, Université de Nantes, France, would be to use Cassini to study the newly discovered lakes.

Huygens has exceeded expectations and shown Titan to be an 'alien earth', giving planetary scientists a new world of fascination to explore.


Note

Cassini-Huygens is a project of international collaboration between NASA, ESA and ASI.

Source: ESA - News

24 January 2007
A pair of rare celestial alignments that occurred in November 2003 helped an international team of astronomers investigate the far-off world of Titan. In particular, the alignments helped validate the atmospheric model used to design the entry trajectory for ESA's Huygens probe.

Now the unique results are helping to place the descent of Huygens in a global context, and to investigate the upper layers of Titan’s atmosphere.

Occasionally Titan passes directly in front of a distant star. When it does so, the light from the star is blocked out. Because Titan has a thick atmosphere, the light does not 'turn off' straight away. Instead, it drops gradually as the blankets of atmosphere slide in front of the star. The way the light drops tells astronomers about the atmosphere of Titan.


By pure chance on 14 November 2003, fourteen months before Huygens’ historic descent through Titan's atmosphere, Titan passed in front of two stars, just seven and a half hours apart. Bruno Sicardy, Observatoire de Paris, France, organised expeditions to record the occultations, as such events are called.

The first occultation was visible just after midnight from the Indian Ocean and the southern half of Africa. The second could be seen from Western Europe, the Atlantic Ocean, Northern and Central Americas. Teams of astronomers set up along the occultation tracks.


This artist’s impression shows the ‘light curve’ produced by a star passing behind Titan,
Saturn’s biggest moon.

When such occultation events take place, the light from the star is blocked out. Because
Titan has a thick atmosphere, the light does not ‘turn off’ straight away. Instead, it drops
gradually as the blankets of atmosphere slide in front of the star, as the light-curve drawn
here shows. The way the light drops tells astronomers about the atmosphere of Titan.

The peak at the centre of the light curve represents the bright flash occurring at the very
middle of the occultation. This is due to the fact that Titan’s atmosphere acts as a lens,
making the light emitted by the star passing behind converge into a focal point and produce
the flash.

Credits: NASA/JPL/Space Science Institute, ESA. Image by C.Carreau

Sicardy was looking for one observation in particular. "Titan's atmosphere acts like a lens, so at the very middle of the occultation, a bright flash occurs," explains Sicardy. If Titan's atmosphere were a perfectly uniform layer, the central flash would be a pinprick of light, visible only at the very centre of the planet's shadow. However, comparing the results from many telescopes, Sicardy found that the central flash fell across the Earth in a triangular shape.

"It is like the light falling through a glass of water and making bright patterns on the table. The focused light is not perfectly round because the glass is not a perfect lens," says Sicardy. Analysing the shape of the flash showed that Titan’s atmosphere was flattened at the north pole. This was because at the time of the occultation, Titan's south pole was tilted towards the Sun. This warmed the atmosphere there, causing it to rise and move towards the north of the moon, where the atmosphere cooled and sank towards the surface.

There was one other key discovery that the occultation data allowed Sicardy and his team to make. A fast moving, high altitude wind (above 200 kilometres) was blowing around Titan at latitude of 50 degrees north. They estimated that it was moving at 200 metres per second (or 720 kilometres per hour) and would encircle the planet in less than one terrestrial day.


Artist's impression of the descent and landing sequence followed by ESA''s Huygens probe
to Titan.

Credits: NASA

"It is like the jet stream on Earth," says Sicardy, "Furthermore, we told the Huygens team to expect some bumps near 510 kilometres altitude, due to a narrow and sudden temperature variation."

Indeed, Huygens was jolted by exactly such a layer during its 14 January 2005 entry. "A temperature inversion was indeed detected by the accelerometers during entry at this very altitude" says Jean-Pierre Lebreton, Huygens project scientist.

The work does not stop there. Even though the Huygens descent took place almost two years ago, the understanding of its data continues to provide key insights into Titan.


Note

The findings appear in the article "The two Titan stellar occultations of 14 November 2003", by Bruno Sicardy et al., published in Journal of geophysical research (Vol. 111, E11S91, doi:10.1029/2005JE002624, 2006).

Source: ESA - News

Titan Dunes over Possible Craters (T23)
January 24, 2007

This radar image of Titan's well-known dunes is distinctive because it may show an age relationship between different classes of features on the surface of this frigid world.

Taken by Cassini's radar mapper on Jan. 13, 2007, during a flyby of Titan, three kinds of terrain can be seen. Throughout the image, the fine striping has been identified as dunes, possibly made from organic material and formed by wind activity. Dunes are a common landform on Titan (see Two Sides of Dunes and Swimming in Dunes). The bright material at the lower right of the image is interpreted as being topographically higher than the dunes that go around it, and several circular features seen at the top center may be craters that are slowly being buried by the dunes. Since the dunes seem to lie over the craters, the dune activity probably occurred later in time.

This image was taken in synthetic aperture mode and has a resolution of approximately 350 meters (1,150 feet). North is toward the top left corner of the image, which is approximately 160 kilometers (100 miles) long by 150 kilometers (90 miles) wide.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm.

Credit: NASA/JPL

Source: NASA/JPL - Cassini

Bands of Titan
February 2, 2007

Titan bears a distinct east-west banded pattern in this Cassini spacecraft image taken in the ultraviolet.

The ultraviolet wavelength allows Cassini to see Titan's stratosphere, where superrotation -- in which the atmosphere moves around the moon faster than Titan rotates -- is strong. The recent appearance of this feature may be a harbinger of seasonal change on Titan.

The moon's halo -- its detached, high-altitude global haze layer -- is visible here as well, and is often its most prominent feature in such ultraviolet views. North on Titan (5,150 kilometers, 3,200 miles across) is up and rotated 6 degrees to the right in this image.

The view was obtained by the Cassini spacecraft narrow-angle camera using a spectral filter sensitive to wavelengths of polarized ultraviolet light. The view was acquired on Dec. 25, 2006 at a distance of approximately 1.3 million kilometers (800,000 miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 123 degrees. Image scale is 8 kilometers (5 miles) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA\'s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

Credit: NASA/JPL/Space Science Institute

Source: NASA/JPL - Cassini

TTitan (T17) Viewed by Cassini's Radar -- Sept. 7, 2006
February 7, 2007

This image of Titan's surface shows the entire scene obtained by the Cassini radar instrument on Sept. 7, 2006. It includes clear examples of the longitudinal dunes, as well as one of only three positively-identified impact craters (on the far left).

Titan's longitudinal dunes, first discovered during the third close flyby of Titan in February 2005 (see Titan, a Geologically Dynamic World), make up most of Titan's equatorial dark regions. These run east-west, are around 1 to 2 kilometers (0.6 to 1.2 miles) wide, spaced 1 to 2 kilometers apart, around 100 meters (109 yards) high, and from 10 to over 100 kilometers (6.2 to 62 miles) long. They curve around the bright features in the image -- which may be high-standing topographic obstacles -- following the prevailing wind pattern. Unlike Earth's silicate dunes, these may be solid organic particles or ice coated with organic material.

The left (eastern-most) portion of the image also shows one of only three impact craters confirmed on Titan so far. Roughly 30 kilometers (18.6 miles) in diameter, it measures about 150 kilometers (93 miles) high by 190 kilometers (118 miles) wide, and its center is at 70 degrees west, 10 degrees north. The difference in overall appearance between this crater, which has a central peak, and those without, such as Sinlap (see Impact Crater with Ejecta Blanket), indicates variations in the conditions of impact, thickness of the crust, or properties of the meteorite that made the crater. The dark floor indicates smooth and/or highly absorbing materials.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm.

Credit: NASA/JPL

Source: NASA/JPL - Cassini

A New Crater on Titan?
February 16, 2007

This radar image of Titan shows a semi-circular feature that may be part of an impact crater. Very few impact craters have been seen on Titan so far, implying that the surface is young. Each new crater identified on Titan helps scientists to constrain the age of the surface.

Taken by Cassini's radar mapper on Jan. 13, 2007, during a flyby of Titan, the image swath revealed what appeared to be the northernmost half of an impact crater. This crater is roughly 180 kilometers (110 miles) wide. Only three impact craters have been identified on Titan and several others, like this one, are likely to also have been caused by impact. The bright material is interpreted to be part of the crater's ejecta blanket, and is likely topographically higher than the surrounding plains. The inner part of the crater is dark, and may represent smooth deposits that have covered the inside of the crater.

This image was taken in synthetic aperture mode and has a resolution of approximately 350 meters (1,150 feet). North is toward the top left corner of the image, which is approximately 240 kilometers (150 miles) wide by 140 kilometers (90 miles) high. The image is centered at about 26.5 degrees north and 9 degrees west.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm.

Credit: NASA/JPL

Source: NASA/JPL - Cassini

Ganesa Macula
February 16, 2007

This radar image of Titan shows Ganesa Macula, interpreted as a cryovolcano (ice volcano), and its surroundings. Cryovolcanism is thought to have been an important process on Titan and may still be happening today.

This mosaic was made from images obtained by the Cassini radar mapper on two flybys. The lower part of the image was from the flyby on Oct. 26, 2005, while the upper part was from the Jan. 13, 2007, flyby. Ganesa macula is the dark circular feature seen on the lower left of the mosaic. Bright rounded features, interpreted as cryovolcanic flows, are seen towards the top and the right of the mosaic.

This image mosaic was taken in synthetic aperture mode. The resolution of the images is approximately 350 meters (1,150 feet). North is toward the top. The image mosaic is about 570 kilometers (354 miles) wide and 390 kilometers (240 miles) high.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm.

Credit: NASA/JPL

Source: NASA/JPL - Cassini

This animation shows a mosaic of imagery from Cassini's radar instrument obtained during three flybys of Titan's north pole: T16 (July 22, 2006), T18 (Sept. 23, 2006) and T19 (Oct. 9, 2006). The most striking discovery from these flybys was the near-polar hydrocarbon lakes, which are far darker than the surrounding terrain. Ranging in size from a few kilometers up to about 100 kilometers (62 miles) in diameter, they are most likely the result of increased rainfall and decreased evaporation at the cold higher latitudes. Scientists will be looking for signs of change in lake shape in future flybys covering the same area, which may indicate changes in lake level.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm.

Credit: NASA/JPL

Source: NASA/JPL - Cassini

The Banded North
February 19, 2007

Looking toward high northern latitudes on Titan, the Cassini spacecraft spies a banded pattern encircling the pole. This sort of feature is what scientists expect to see in the stratosphere of Titan, where the atmosphere is superrotating, or moving around the moon faster than the moon itself rotates.

Titan is 5,150 kilometers (3,200 miles) across.

Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were taken by the Cassini spacecraft wide-angle camera on Jan. 28, 2007 at a distance of approximately 196,000 kilometers (122,000 miles) from Titan. Image scale is 12 kilometers (7 miles) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA\'s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

Credit: NASA/JPL/Space Science Institute

Source: NASA/JPL - Cassini

Titan (T18) Viewed by Cassini's Radar -- Sept. 23, 2006
February 20, 2007

This radar image, obtained by Cassini's radar instrument during a near-polar flyby on Sept. 23, 2006, is the second scene that shows clear shorelines reminiscent of terrestrial lakes.

With Titan's colder temperatures and hydrocarbon-rich atmosphere, these lakes most likely contain a combination of methane and ethane (both hydrocarbons), not water. This high-latitude opportunity confirmed scientists' predictions that lakes would be present here, consistent with calculations that suggested that hydrocarbons would be stable as liquids at the colder, high latitudes. It also showed unusual complex terrain, the origin of which remains a mystery.

The image is illuminated by the radar from the top, and shows features as small as about 300 meters (980 feet). Starting at the left (63 degrees north latitude by 255 degrees west longitude), where the terrain appears bland and dark, the swath heads northeast into a more rugged, mottled terrain, probably containing dried lakes and canyons formed by the presence of liquid hydrocarbons.

The first lake, an irregular, almost-triangular shape about 16 kilometers (10 miles) across at the widest point, can be seen near the bottom of the image; it appears to be fed by two channels from the south. Several more lakes can be seen about one-third of the way into the swath, near the closest approach to the pole, (north of 75 degrees north latitude), including Titan's "kissing lakes," each 20 to 25 kilometers (12 to 16 miles) across. Two other lakes feature narrow or angular bays, including a broad peninsula that on Earth would be evidence that the surrounding terrain is higher and confines the liquid. Continuing on, about three-quarters of the way through the swath, the terrain becomes brighter and more rugged, again indicating possible dried lakes and canyon-like structures. A long 100-kilometer (60-mile) series of grooves appears, likely carved by liquids. Next is an area of bright terrain with an unusual directional texture, indicating possible dunes, but brighter and perhaps different in nature than those seen elsewhere. Finally, towards the end of the swath, where the image quality is poorest, the terrain becomes mottled and difficult to interpret.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm.

Credit: NASA/JPL

Source: NASA/JPL - Cassini

Titan: Larger and Larger Lakes
February 27, 2007

This radar image, obtained by Cassini's radar instrument during a near-polar flyby on Feb. 22, 2007, shows a big island smack in the middle of one of the larger lakes imaged on Saturn's moon Titan. This image offers further evidence that the largest lakes are at the highest latitudes.

The island is about 90 kilometers (62 miles) by 150 kilometers (93 miles) across, about the size of Kodiak Island in Alaska or the Big Island of Hawaii. The island may actually be a peninsula connected by a bridge to a larger stretch of land. As you go farther down the image, several very small lakes begin to appear, which may be controlled by local topography.

This image was taken in synthetic aperture mode at 700 meter (2,300 feet) resolution. North is toward the left. The image is centered at about 79 north degrees north and 310 degrees west.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm.

Credit: NASA/JPL

Source: NASA/JPL - Cassini

Titan Features and Interactions
March 1, 2007

This radar image, obtained by Cassini's radar instrument during a near-polar flyby on Feb. 22, 2007, shows dunes surrounding a bright feature on Saturn's moon Titan.

Dunes have been previously seen on Titan, so far concentrated near the equator. They are thought to be composed of small hydrocarbon or water ice particles -- probably about 250 microns in diameter, similar to sand grains on Earth. These are formed into dunes by the prevailing west-to-east surface winds. Because of the shape and length of the dunes, they are probably "longitudinal" (lying in the same direction as the average wind) rather than transverse dunes, which form across the wind and are more common on Earth.

There are several kinds of interaction between the dunes and the brighter features in this image. At the left, the dunes seem to be covering the bright material, while at the center and right, they seem to be terminated against it. At the lower center and lower right, they flow around it (see also Swimming in Dunes and Dunes and More Dunes). These various interactions will help us to determine the nature of both of these features.

This image was taken in synthetic aperture mode at 700-meter (2,300-foot) resolution. North is toward the left. The image is centered at about 3.5 degrees south latitude and 37.3 degrees west longitude.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm.

Credit: NASA/JPL

Source: NASA/JPL - Cassini

This image provides a comparison between the Huygens landing site on Titan as viewed
by the Cassini Imaging Science Subsystem (ISS) and the NACO/SDI instrument mounted
on the 8-metre Yepun telescope of the VLT (Very Large Telescope) station, in Chile.

From the two images it is possible to see a high consistency between the two measurements.
The Cassini image - taken in the near-infrared (938 nanometres)- shows the Huygens
landing site map wrapped around Titan, rotated to the same position as the January 2005
NACO/SDI observations.

The coloured lines outline the regions that were imaged by Cassini at different resolutions.
The lower-resolution imaging sequences are outlined in blue. Other areas have been
specifically targeted to build moderate and high resolution mosaics of surface features.
These include the site where the Huygens probe has touched down on 14 January 2005,
marked with the yellow X, and located at a latitude of 10.3° south and a longitude of 192.32°
west (or 167.7° east).

The landing site is located on the boundary between the bright region called Adiri and
the dark one called Shangri-la.

The red colour on the NACO/SDI image corresponds to an atmospheric filter at 1.625
micron, while the blue colour corresponds to a filter for the surface at 1.600 and 1.575
micron.

Credits: NASA/JPL/Cassini-ISS/Space Science Institute and ESO/NACO-SDI/VLT

5 March 2007
ESA PR 13-2007. As of 14 March, an epic space mission and one of the founding fathers of the European space endeavour will be forever linked.

ESA, the international Committee for Space Research (COSPAR) and NASA have decided to honour Professor Hubert Curien’s contribution to European space by naming the Huygens landing site on Saturn’s largest moon, Titan, after him.

The naming ceremony for the Huygens landing site, which will be known as the "Hubert Curien Memorial Station", will be held at ESA’s Headquarters on 14 March, in the presence of ESA Council delegates and of Professor Curien’s wife, Mrs Perrine Curien, and one of their sons. Media interested in attending are invited to submit the reply form below.

Huygens' landing on Saturn’s largest moon in January 2005 represented one of the greatest successes achieved by humankind in the history of space exploration. The part played by ESA, in cooperation with NASA and the Italian Space Agency (ASI), was made possible thanks to the commitment of a man who, for several decades, worked to promote and strengthen the role of scientific research in his home country - France - and in Europe. Among his numerous responsibilities, Hubert Curien was French Minister of Research and Space under four Prime Ministers.


Professor Hubert Curien (1924-2005)

As Chairman of the ESA Council from 1981 to 1984, Professor Curien played a crucial part in setting up ESA's former long-term science programme, "Horizon 2000", which included the Huygens mission among its projects.

Professor Roger Bonnet, current President of COSPAR, and former ESA Director of Science (1983-2001), commented: "Curien’s diplomatic skills were hugely influential in bringing about the birth of European space science. In 1985, his support was pivotal when the European ministers had to decide how to build a solid space science programme and ensure that it would be financially sustainable in the long term."

"ESA's present science programme, Cosmic Vision, draws on the heritage left by Hubert Curien", said Professor David Southwood, ESA's current Director of Science. "He encouraged cooperation between nations in the belief that space research is fundamental to the progress and welfare of a knowledge-based society like ours. He also promoted the concept of long-term planning", he continued. "It would seem almost inconceivable today to initiate any space venture without such pillar concepts in mind".

"The role played by Hubert Curien in creating a European space dimension, with all its various facets, has been absolutely essential", said Jean-Jacques Dordain, ESA Director General. "Curien was one of the fathers of the Ariane Programme, which provided Europe with independent access to space, and one of those who, in the late seventies, persuaded other countries to join ESA by creating the 'fair return' system for industrial contracts." Dordain continued, "This exceptional man of vision was appreciated by all for his scientific competence and his outstanding human, political and diplomatic abilities. It is therefore a true honour for us to pay tribute to his memory by linking his name forever to this very significant place on the surface of an alien world that, also thanks to him, we were able to reach."

Notes

Short biography of Hubert Curien

Hubert Curien was born on 30 October 1924 in the Vosges region of eastern France. While a student, he enlisted in the French resistance and was commended for bravery in action. He entered the Ecole Normale Supérieure in Paris and went on to pursue a research career in crystallography, joining the Sorbonne Mineralogy Laboratory. He was always keen to encourage collaboration between mineralogists and physicists. He was appointed lecturer at the University of Paris in 1949, obtained his PhD in 1951, and became professeur in 1956. From 1968 onwards, he continued with his teaching career at the 'Pierre et Marie Curie/Paris VI' University, which he left only in 1994, despite all his political duties.

Aside from his scientific career, Hubert Curien is known mostly for his managerial and political responsibilities, pursued with commitment, efficiency and vision both in France and in Europe. He left his mark on an impressive number of scientific institutions. From 1966 to 1969, he was Scientific Director for Physics at the CNRS, France's scientific research centre, becoming its Director General in 1969. In 1973, he was given responsibility for reorganising research in France. From 1976 to 1984, he was President of the French space agency (CNES), and from 1984 to1993, served as Minister of Research and Space under four different governments.

From 1981 to 1984, he was Chairman of the ESA Council, and he is now still remembered – among his many achievements – as one of the fathers of the Ariane programme and as a promoter of a Europe united through science. From 1994 to 1996, he also headed the European Organization for Nuclear Research (CERN), and in 1993, was elected to the French Academy of Science.

For his work, Hubert Curien received the highest distinctions and awards. He was known for his great intelligence and managerial and political abilities, but also for his simplicity, modesty, sense of humour and willingness to listen to others. He died on 6 February 2005, and is survived by his wife, Perrine, and their sons, Nicolas, Christophe and Pierre-Louis.

Huygens highlights


Artist's impression of the descent and landing sequence followed by ESA''s Huygens probe
to Titan.

Credits: ESA - C. Carreau

The European-built Huygens probe was part of the Cassini-Huygens mission to Saturn - a joint endeavour of ESA, NASA and the Italian Space Agency (ASI). It is the most ambitious effort in planetary space exploration ever mounted. Launched on 15 October 1997, Cassini (a sophisticated robotic spacecraft designed to orbit the ringed planet and study the Saturnian system in detail), bearing the Huygens probe, reached Saturn on 1 July 2004. Cassini delivered Huygens to Saturn’s largest moon, Titan, on 14 January 2005. This was the first ever descent and landing onto a celestial body in the outer Solar System, and it provided the most spectacular view of Titan yet.

During its 2½-hour descent onto this alien world, Huygens performed