Posted on by Fraser Cain

Spirit Reaches Columbia Hills

Image credit: NASA/JPL
NASA’s Mars rovers are delighting scientists with their extra credit assignments. Both rovers successfully completed their primary three-month missions in April.

The Spirit rover is exploring a range of martian hills that took two months to reach. It is finding curiously eroded rocks that may be new pieces to the puzzle of the region’s past. Spirit’s twin, Opportunity, is also negotiating sloped ground. It is examining exposed rock layers inside a crater informally named “Endurance.”

“Both rovers have begun exploring brand new places,” said Dr. Mark Adler, mission manager at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “Opportunity has entered Endurance Crater. Spirit has arrived at the Columbia Hills. Both rovers are getting their second wind in bonus time, and we are very excited about the scientific potential we see at their new homes. Of course, the terrain at both locations is challenging, one up and one down. We are making certain that we proceed safely to keep these wonderful machines as healthy as we can for as long as we can.”

Spirit began climbing into Columbia Hills late last week, and right away sent pictures of tantalizing rocks. “Some of the rocks appear to be disintegrating. They have an odd kind of rotting appearance, with soft interiors and resistant rinds or hulls,” said Dr. Larry Soderblom, a rover science-team member from the U.S. Geological Survey, Flagstaff, Ariz. “The strangest things we’ve encountered are what we’re calling hooded cobras, which are evidently the resistant remnants of some of those rocky rinds. They stand above the surface like small canopies.”

Another rock, dubbed “Pot of Gold,” appears to have nodules and resistant planes in a softer matrix. Scientists have chosen it as a target for Spirit to examine with the instruments on the rover’s robotic arm. Afterwards, controllers plan to send Spirit to an outcrop farther uphill.

“Although it’s too early to even speculate as to the processes these rocks have recorded, we are tremendously excited over the new prospects,” Soderblom said.

The Columbia Hills rise approximately 90 meters (about 300 feet) above a plain Spirit crossed to reach them. Scientists anticipate a complex blend of rocks in the hills, perhaps holding evidence about a broader range of environmental conditions than has been seen in the volcanic rubble surfacing the plain. The entire area Spirit is exploring is within Gusev Crater. Orbital images suggest water may have once flowed into this Connecticut-sized basin.

“Halfway around Mars, Opportunity has driven about five meters (16 feet) into stadium-sized Endurance Crater. “As we look back up toward the rim, we can see the progress we’ve made,” said Scott McLennan, science-team member from the State University of New York, Stony Brook.

Opportunity’s first target inside the crater is a flat-lying stone about 36 centimeters by 15 centimeters (14 inches by 6 inches) dubbed “Tennessee” for its shape. Opportunity will inspect it for analysis with the spectrometers and microscopic imager on the rover’s robotic arm. It is in a layer geologists believe corresponds to sulfate-rich rocks. The rocks are similar to those, in which Opportunity previously found evidence for a body of water covering the ground long ago.

“The next step will be to move farther down from this layer to our first close-up look at a different sedimentary sequence,” McLennan said. “Color differences suggest at least three lower, older layers are exposed below Opportunity’s location.”

“The interpretation of those lower units is in a state of flux,” he said. “At first, we thought we would encounter poorly consolidated, sandy material. But as we get closer, we’re seeing more-consolidated, harder rock deeper into the crater. If we can get to the lower units, this will be the first detailed stratigraphic section ever done on another planet. We’re doing exactly what a field geologist would be doing.”

Spirit is showing what may be the first sign of age and wear. “The right front wheel is drawing about two to three times as much current as the other wheels, and that may be a symptom of degradation,” Adler said. “There may be steps we can take to improve it. We’ll be studying that possibility during the next few weeks.”

JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover project for NASA’s Office of Space Science, Washington, D.C. Images and additional information about the project are available from JPL at http://marsrovers.jpl.nasa.gov and from Cornell University, Ithaca, N.Y., at http://athena.cornell.edu.

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Did Comets Create the Earth’s Oceans?

Artist's conception of asteroids or comets bearing water to a proto-Earth. Credit: Harvard-Smithsonian Center for Astrophysics

Did the Earth form with water locked into its rocks, which then gradually leaked out over millions of years? Or did the occasional impacting comet provide the Earth?s oceans? The Ptolemy experiment on Rosetta may just find out?

The Earth needed a supply of water for its oceans, and the comets are large celestial icebergs – frozen reservoirs of water orbiting the Sun.

Did the impact of a number of comets, thousands of millions of years ago, provide the Earth with its supply of water? Finding hard scientific evidence is surprisingly difficult.

Ptolemy may just provide the information to understand the source of water on Earth. It is a miniature laboratory designed to analyse the precise types of atoms that make up familiar molecules like water.

Atoms can come in slightly different types, known as isotopes. Each isotope behaves almost identically in a chemical sense but has a slightly different weight because of extra neutrons in its nucleii.

Ian Wright is the principal investigator for Ptolemy, an instrument on Rosetta?s Philae lander. By analysing with Ptolemy the mix of isotopes found in Comet 67P/Churyumov-Gerasimenko, he hopes to say whether comet water is similar to that found in Earth?s oceans. Recent results from the ground-based observation of another comet, called LINEAR, suggested that they probably are the same.

If this is true, then scientists have solved another puzzle. However, if the comets are not responsible for Earth?s oceans, then planetary scientists and geophysicists will have to look elsewhere.

For example, the answer could be closer to home, through processes related to vulcanism. Also, meteorites (chunks of asteroids or comets that fall to Earth) have been found to contain water but it is bound to the minerals and in nothing like the quantity found in comets.

However, since the Earth formed from rocks similar to the asteroids, it is feasible that enough water could have been supplied that way.

If comets did not supply Earth?s oceans then it implies something amazing about the comets themselves. If Ptolemy finds that they are made of extremely different isotopes, it means that they may not have formed in our Solar System at all. Instead, they could be interstellar rovers captured by the Sun?s gravity.

Rosetta, Philae and Ptolemy will either solve one scientific mystery, or open another whole set of new ones.

Original Source: ESA News Release

Posted on by Fraser Cain

Titan Targeted

Image credit: NASA/JPL/Space Science Institute
Cassini?s finely-tuned vision reveals hazes high in the skies over Titan in this narrow angle camera image from May 22, 2004. Here the northern hemisphere is notably brighter than the southern hemisphere. This trait was noticed in images returned by the Voyager spacecraft, but the effect is presently reversed, North to South, as Titan is currently experiencing opposite seasons from those during the Voyager epoch 23 years ago.

The image was taken from a distance of 21.7 million kilometers (13.5 million miles) from Saturn through a filter sensitive to strong absorption by methane gas (centered at 889 nanometers). The image scale is 129 kilometers (80 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 Cassini-Huygens mission for NASA’s Office of Space Science, Washington, D.C. The imaging team is based at the Space Science Institute, Boulder, Colorado.

For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org.

Posted on by Fraser Cain

Ultra Cool Star Measured

Image credit: ESO
Using ESO’s Very Large Telescope at Paranal and a suite of ground- and space-based telescopes in a four-year long study, an international team of astronomers has measured for the first time the mass of an ultra-cool star and its companion brown dwarf. The two stars form a binary system and orbit each other in about 10 years.

The team obtained high-resolution near-infrared images; on the ground, they defeated the blurring effect of the terrestrial atmosphere by means of adaptive optics techniques. By precisely determining the orbit projected on the sky, the astronomers were able to measure the total mass of the stars. Additional data and comparison with stellar models then yield the mass of each of the components.

The heavier of the two stars has a mass around 8.5% of the mass of the Sun and its brown dwarf companion is even lighter, only 6% of the solar mass. Both objects are relatively young with an age of about 500-1,000 million years.

These observations represent a decisive step towards the still missing calibration of stellar evolution models for very-low mass stars.

Telephone number star
Even though astronomers have found several hundreds of very low mass stars and brown dwarfs, the fundamental properties of these extreme objects, such as masses and surface temperatures, are still not well known. Within the cosmic zoo, these ultra-cool stars represent a class of “intermediate” objects between giant planets – like Jupiter – and “normal” stars less massive than our Sun, and to understand them well is therefore crucial to the field of stellar astrophysics.

The problem with these ultra-cool stars is that contrary to normal stars that burn hydrogen in their central core, no unique relation exists between the luminosity of the star and its mass. Indeed, luminosities and surface temperatures of ultra-cool dwarf stars depend both on their age and their mass. An older, somewhat more massive ultra-cool dwarf can thus have exactly the same temperature as a younger, less massive one.

It is therefore a basic goal of modern astrophysics to obtain independently the masses of an ultra-cool dwarf star. This is in principle possible by studying such objects that are members in a binary system.

This is precisely what an international team of astronomers has now done in a four-year long study of a binary stellar system with an ultra-cool dwarf star, using a plethora of top telescopic facilities, including ESO’s Very Large Telescope, as well as Keck I and Gemini North in Hawaii and also the Hubble Space Telescope. This system – with the telephone number name of 2MASSW J0746425+2000321 – is located at a distance of 40 light-years.

The astronomers used high-angular-resolution imaging to see both stars in the binary system and to measure their motion over a four-year period. However, this is more easily said than done, as the separation on the sky between the two stars is quite small: between 0.13 and 0.22 arcsec. This corresponds to the size of a 1-Euro coin, seen at a distance of about 25 km.

This separation is so small that it is normally not possible to differentiate the two stars due to the blurring effect of atmospheric turbulence (the “seeing”). It is therefore necessary to use the technique of adaptive optics. This wonderful method is based on the measurement of the image quality in real-time and sending corresponding corrective signals up to 100 times every second to a small deformable mirror, located in front of the detector. As the mirror continuously modifies its shape, the disturbing effect of the turbulence is neutralised. Applied at the VLT, this technique has resulted in images which are at least ten times sharper than the “seeing” and which therefore show many more details in the observed objects.

At the Very Large Telescope, the astronomers used the state-of-the-art adaptive optics NACO instrument. Says Herv? Bouy, principal author of the paper presenting the results described here: “NACO offers the possibility to work in the infrared and is therefore ideally suited for the study of ultra-cool stars, which emit most of their light in this wavelength range. With the combination of the high efficiency of NACO and the VLT, and the excellent atmospheric conditions prevailing at Paranal, we were able to achieve very sharp images of this binary stellar system, almost as good as if the telescope were located in space.”

Ultra-cool and on diet
During their four-year long study, seven different relative positions of the two components of the binary system were measured and Herv? Bouy and his co-workers were able to determine with good precision the stellar orbits. They find that the two stars revolve around each other once every 10 years and that their physical separation is only 2.5 times the distance of the Earth to the Sun – as astronomers say, 2.5 Astronomical Units. Using Kepler’s laws, it is then straightforward to derive the total mass of the system. The obtained value is less than 15 % of the mass of the Sun.

The astronomers then used the photometric data of each star obtained in several wavebands, as well as spectra obtained with the Hubble Space Telescope to study the two objects in more detail. Using the latest stellar models of the group of the Ecole Normale Sup?rieure de Lyon, they found that both stars have roughly the same surface temperature, around 1500 ?C (1800 K). For a star, this is ultra-cool indeed – by comparison, the surface temperature of the Sun is more than three times higher.

Using theoretical models, the team also found that the two stars are rather young (in astrophysical terms) – their age is between 500 and 1,000 million years only. The more massive of the two has a mass between 7.5 and 9.5% the mass of the Sun, while its companion has a mass between 5 and 7% of the solar mass.

Objects weighing less than about 7% of our Sun have been variously called “Brown Dwarfs”, “Failed Stars” or “Super Planets”. Indeed, since they have no sustained energy generation by thermal nuclear reactions in their interior, many of their properties are more similar to those of giant gas planets in our own solar system such as Jupiter, than to stars like the Sun.

The system 2MASSW J0746425+2000321 is thus apparently made up of a brown dwarf orbiting a slightly more massive ultra-cool dwarf star. It is a true “Rosetta stone” in the new field of low-mass stellar astrophysics and further studies will surely provide more valuable information about these objects in the transitional zone between stars and planets.

Original Source: ESO News Release

Posted on by Fraser Cain

Cassini Passes Phoebe

Image credit: NASA/JPL/Space Science Institute
Images collected during the Cassini-Huygens close fly-by of Saturn’s moon Phoebe give strong evidence that the tiny moon may be rich in ice and covered by a thin layer of darker material.

Its surface is heavily battered, with large and small craters. It might be an ancient remnant of the formation of the Solar System.

On Friday 11 June, at 21:56 CET, the Cassini-Huygens spacecraft flew by Saturn’s outermost moon Phoebe, coming within approximately 2070 kilometres of the satellite’s surface. All eleven on-board instruments scheduled to be active at that time worked flawlessly and acquired data.

The first high-resolution images show a scarred surface, covered with craters of all sizes and large variation of brightness across the surface.

Phoebe is a peculiar moon amongst the 31 known satellites orbiting Saturn. Most of Saturn’s moons are bright but Phoebe is very dark and reflects only 6% of the Sun’s light. Another difference is that Phoebe revolves around the planet on a rather elongated orbit and in a direction opposite to that of the other large moons (a motion known as ‘retrograde’ orbit).

All these hints suggested that Phoebe, rather than forming together with Saturn, was captured at a later stage. Scientists, however, do not know whether Phoebe was originally an asteroid or an object coming from the ‘Kuiper Belt’.

The stunning images obtained by Cassini’s high-resolution camera now seem to indicate that it contains ice-rich material and is covered by a thin layer of dark material, probably 300-500 metres thick.

Scientists base this hypothesis on the observation of bright streaks in the rims of the largest craters, bright rays radiating from smaller craters, grooves running continuously across the surface of the moon and, most importantly, the presence of layers of dark material at the top of crater walls.

“The imaging team is in hot debate at the moment on the interpretations of our findings,” said Dr Carolyn Porco, Cassini imaging team leader at the Space Science Institute in Boulder, USA.

“Based on our images, some of us are leaning towards the view that has been promoted recently, that Phoebe is probably ice-rich and may be an object originating in the outer solar system, more related to comets and Kuiper Belt objects than to asteroids.”

The high-resolution images of Phoebe show a world of dramatic landforms, with landslides and linear structures such as grooves, ridges and chains of pits. Craters are ubiquitous, with many smaller than one kilometre.

“This means, besides the big ones, lots of projectiles smaller than 100 metres must have hit Phoebe,” said Prof. Gerhard Neukum, Freie Universitaet Berlin, Germany, and a member of the imaging team. Whether these projectiles came from outside or within the Saturn system is debatable.

There is a suspicion that Phoebe, the largest of Saturn’s outer moons, might be parent to the other, much smaller retrograde outer moons that orbit Saturn. They could have resulted from the impact ejecta that formed the many craters on Phoebe.

Besides these stunning images, the instruments on board Cassini collected a wealth of other data, which will allow scientists to study the surface structures, determine the mass and composition of Phoebe and create a global map of it.

“If these additional data confirm that Phoebe is mostly ice, covered by layers of dust, this could mean that we are looking at a ‘leftover’ from the formation of the Solar System about 4600 million years ago,” said Dr Jean-Pierre Lebreton, ESA Huygens Project Scientist.

Phoebe might indeed be an icy wanderer from the distant outer reaches of the Solar System, which, like a comet, was dislodged from the Kuiper Belt and captured by Saturn when the planet was forming.

Whilst studying the nature of Phoebe may give scientists clues on the origin of the building blocks of the Solar System, more data are needed to reconstruct the history of our own neighbourhood in space.

With that aim, ESA’s Rosetta mission is on its way to study one of these primitive objects, Comet 67P/Churyumov-Gerasimenko, from close quarters for over a year and land a probe on it.

The fly-by of Phoebe on 11 June was the only one that Cassini-Huygens will perform with this mysterious moon. The mission will now take the spacecraft to its closest approach to Saturn on 1 July, when it will enter into orbit around the planet.

From there, it will conduct 76 orbits of Saturn over four years and execute 52 close encounters with seven other Saturnian moons. Of these, 45 will be with the largest and most interesting one, Titan. On 25 December, Cassini will release the Huygens probe, which will descend through Titan’s thick atmosphere to investigate its composition and complex organic chemistry.

Original Source: ESA News Release

Posted on by Fraser Cain

SpaceShipOne Set for Launch in a Week

In just one week Scaled Composite’s SpaceShipOne will make an attempt to become the first privately-built vehicle to reach space – an altitude of 100 km (62 miles). Thousands of people are expected to show up at the runway in California’s Mojave Desert to watch the launch and suborbital flight. This won’t be an official attempt to win the Ansari X Prize; however, but the company is planning to try for the $10 million prize if this flight is successful. Billionaire Paul Allen has contributed $20 million to the development of SpaceShipOne.

Posted on by Fraser Cain

Close Up on Phoebe Crater

Image credit: NASA/JPL/Space Science Institute
This eye-popping high-resolution image of Phoebe’s pitted surface taken very near closest approach shows a 13-kilometer (8-mile) diameter crater with a debris-covered floor. Part of another crater of similar size is visible at left, as is part of a larger crater at top and many scattered smaller craters. The radial streaks in the crater are due to downslope movements of loose fragments from impact ejecta. Also seen are boulders ranging from about 50 to 300 meters (160 to 990 feet) in diameter. The building-sized rocks may have been excavated by large impacts, perhaps from some other region of Phoebe rather than the craters seen here. There is no visible evidence for layering of ice and regolith or a hardened crust in this region, as on other parts of this moon.

Some of the relatively bright spots are from small impacts that excavated bright material from beneath the dark surface. Images like this provide information about impact and regolith processes on Phoebe.

This image was obtained at a phase, or Sun-Phoebe-spacecraft, angle of 78 degrees, and from a distance of 11,918 kilometers (7,407 miles). The image scale is approximately 18.5 meters (60.5 feet) per pixel. The illumination is from the right. No enhancement was performed on this image.

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 Office of Space Science, Washington, D.C. The imaging team is based at the Space Science Institute, Boulder, Colorado.

For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org.

Original Source: CICLOPS News Release

Posted on by Fraser Cain

Cassini Makes its Phoebe Flyby

Image credit: NASA/JPL/Space Science Institute
Phoebe?s true nature is revealed in startling clarity in this mosaic of two images taken during Cassini?s flyby on June 11, 2004. The image shows evidence for the emerging view that Phoebe may be an ice-rich body coated with a thin layer of dark material. Small bright craters in the image are probably fairly young features. This phenomenon has been observed on other icy satellites, such as Ganymede at Jupiter. When impactors slammed into the surface of Phoebe, the collisions excavated fresh, bright material — probably ice — underlying the surface layer. Further evidence for this can be seen on some crater walls where the darker material appears to have slid downwards, exposing more light-colored material. Some areas of the image that are particularly bright ? especially near lower right ? are over-exposed.

An accurate determination of Phoebe?s density ? a forthcoming result from the flyby ? will help Cassini mission scientists understand how much of the little moon is comprised of ices.

This spectacular view was obtained at a phase, or Sun-Phoebe-spacecraft, angle of 84 degrees, and from a distance of approximately 32,500 kilometers (20,200 miles). The image scale is approximately 190 meters (624 feet) per pixel. No enhancement was performed on this image.

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 Office of Space Science, Washington, D.C. The imaging team is based at the Space Science Institute, Boulder, Colorado.

For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org.

Original Source: CICLOPS News Release

Posted on by Fraser Cain

Youngest Black Hole Found?

Image credit: NRAO
Astronomers using a global combination of radio telescopes to study a stellar explosion some 30 million light-years from Earth have likely discovered either the youngest black hole or the youngest neutron star known in the Universe. Their discovery also marks the first time that a black hole or neutron star has been found associated with a supernova that has been seen to explode since the invention of the telescope nearly 400 years ago.

A supernova is the explosion of a massive star after it exhausts its supply of nuclear fuel and collapses violently, rebounding in a cataclysmic blast that spews most of its material into interstellar space. What remains is either a neutron star, with its material compressed to the density of an atomic nucleus, or a black hole, with its matter compressed so tightly that its gravitational pull is so strong that not even light can escape it.

A team of scientists studied a supernova called SN 1986J in a galaxy known as NGC 891. The supernova was discovered in 1986, but astronomers believe the explosion actually occurred about three years before. Using the National Science Foundation’s Very Long Baseline Array (VLBA), Robert C. Byrd Green Bank Telescope (GBT), and Very Large Array (VLA), along with radio telescopes from the European VLBI Network, they made images that showed fine details of how the explosion evolves over time.

“SN 1986J has shown a brightly-emitting object at its center that only became visible recently. This is the first time such a thing has been seen in any supernova,” said Michael Bietenholz, of York University in Toronto, Ontario. Bietenholz worked with Norbert Bartel, also of York University, and Michael Rupen of the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, on the project. The scientists reported their findings in the June 10 edition of Science Express.

“A supernova is likely the most energetic single event in the Universe after the Big Bang. It is just fascinating to see how the smoke from the explosion is blown away and how now after all these years the fiery center is unveiled. It is a textbook story, now witnessed for the first time,” Bartel said.

Analysis of the bright central object shows that its characteristics are different from the outer shell of explosion debris in the supernova.

“We can’t yet tell if this bright object at the center is caused by material being sucked into a black hole or if it results from the action of a young pulsar, or neutron star,” said Rupen.

“It’s very exciting because it’s either the youngest black hole or the youngest neutron star anybody has ever seen,” Rupen said. The youngest pulsar found to date is 822 years old.

Finding the young object is only the beginning of the scientific excitement, the astronomers say.

“We’ll be watching it over the coming years. First, we hope to find out whether it’s a black hole or a neutron star. Next, whichever it is, it’s going to give us a whole new view of how these things start and develop over time,” Rupen said.

For example, Rupen explained, if the object is a young pulsar, learning the rate at which it is spinning and the strength of its magnetic field would be extremely important for understanding the physics of pulsars.

The scientists point out that it will be important to observe SN 1986J at many wavelengths, not just radio, but also in visible light, infrared and others.

In addition, the astronomers also now want to look for simiilar objects elsewhere in the Universe.

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Original Source: NRAO News Release

Posted on by Fraser Cain

Cassini Will Reach Phoebe Today

Image credit: NASA/JPL/Space Science Institute
As Cassini sails toward its rendezvous with Phoebe, details on the small, dark moon are coming into view at a dizzying pace. The images shown here were taken only 13 hours apart on June 10, 2004, just one day prior to closest approach, and show a dramatic increase in detail between these two views. On Phoebe, the spin axis points up and approximately 13 degrees to the left of the boundary between day and night. Phoebe completes one rotation about its spin axis in 9 hours and 16 minutes. We are looking at opposite hemispheres in these two views.

A large crater, roughly 50 km (31 miles) across, is visible in the image on the left. The image on the right shows a body heavily pitted with craters of varying sizes, including very large ones, and displaying a substantial amount of variation in surface brightness. Features that appear to be cliffs may in fact be the boundaries between large craters. Despite its exaggerated topography, Phoebe is more round than irregular in shape.

Left to right, the two views were obtained at a phase, or Sun-Phoebe-spacecraft, angle of 87 degrees, and from distances ranging from 956,000 kilometers (594,000 miles) to 658,000 kilometers (409,000 miles). The image scale ranges from 5.7 to 3.9 kilometers (3.5 to 2.4 miles) per pixel. To aid visibility, the images were magnified three times via linear interpolation; no contrast enhancement was performed.

Phoebe is approximately 220 kilometers (137 miles) wide. Its many secrets await as Cassini draws close to its only flyby with this mysterious outer moon of Saturn at 1:56 pm PDT on June 11, 2004.

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 Office of Space Science, Washington, D.C. The imaging team is based at the Space Science Institute, Boulder, Colorado.

For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org.

Original Source: CICLOPS News Release