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martes, 1 de diciembre de 2015

NASA : Water World .- Mundo Acuático en Saturno

Hola amigos: A VUELO DE UN QUINDE EL BLOG., Aunque el satélite  Encelado y los anillos de Saturno están en gran parte compuestas de hielo de agua, muestran características muy diferentes. Las pequeñas partículas de los anillos son demasiado pequeños para retener el calor interno y no hay manera de entrar en calor, por lo que son congelados y geológicamente muerto. Encelado, por otra parte, está sujeto a fuerzas que calientan su interior hasta este mismo día. Esto se traduce en sus famosos chorros de agua del polo sur, que son sólo visibles por encima de la extremidad oscura, en el sur de la Luna, junto con un océano bajo la superficie.
More information............

Enceladus and Saturn's rings
Although Enceladus and Saturn's rings are largely made up of water ice, they show very different characteristics. The small ring particles are too tiny to retain internal heat and have no way to get warm, so they are frozen and geologically dead. Enceladus, on the other hand, is subject to forces that heat its interior to this very day. This results in its famous south polar water jets, which are just visible above the moon’s dark, southern limb, along with a sub-surface ocean.

Recent work by Cassini scientists suggests that Enceladus (313 miles or 504 kilometers across) has a global ocean of liquid water under its surface. This discovery increases scientists' interest in Enceladus and the quest to understand the role of water in the development of life in the solar system. (For more on the sub-surface ocean, see this story.)

This view looks toward the unilluminated side of the rings from about 0.3 degrees below the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 29, 2015.

The view was acquired at a distance of approximately 630,000 miles (1.0 million kilometers) from Enceladus and at a Sun-Enceladus-spacecraft, or phase angle of 155 degrees. Image scale is 4 miles (6 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute

Last Updated: Nov. 30, 2015
Editor: Tony Greicius
Cassini
Dione and Enceladus
Although Dione (near) and Enceladus (far) are composed of nearly the same materials, Enceladus has a considerably higher reflectivity than Dione. As a result, it appears brighter against the dark night sky.

The surface of Enceladus (313 miles or 504 kilometers across) endures a constant rain of ice grains from its south polar jets. As a result, its surface is more like fresh, bright, snow than Dione's (698 miles or 1123 kilometers across) older, weathered surface. As clean, fresh surfaces are left exposed in space, they slowly gather dust and radiation damage and darken in a process known as "space weathering."

This view looks toward the leading hemisphere of Enceladus. North on Enceladus is up and rotated 1 degree to the right. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 8, 2015.

The view was acquired at a distance of approximately 52,000 miles (83,000 kilometers) from Dione. Image scale is 1,600 feet (500 meters) per pixel. The distance from Enceladus was 228,000 miles (364,000 kilometers) for an image scale of 1.4 miles (2.2 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
 The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute
Last Updated: Nov. 17, 2015
Editor: Tony Greicius
Saturn
Nov. 9, 2015

Epimetheus Above the Rings

Epimetheus and the rings both orbit in Saturn's equatorial plane
Although Epimetheus appears to be lurking above the rings here, it's actually just an illusion resulting from the viewing angle. In reality, Epimetheus and the rings both orbit in Saturn's equatorial plane.

Inner moons and rings orbit very near the equatorial plane of each of the four giant planets in our solar system, but more distant moons can have orbits wildly out of the equatorial plane. It has been theorized that the highly inclined orbits of the outer, distant moons are remnants of the random directions from which they approached the planets they orbit.

This view looks toward the unilluminated side of the rings from about -0.3 degrees below the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 26, 2015.

The view was obtained at a distance of approximately 500,000 miles (800,000 kilometers) from Epimetheus and at a Sun-Epimetheus-spacecraft, or phase, angle of 62 degrees. Image scale is 3 miles (5 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute

Last Updated: Nov. 9, 2015
Editor: Tony Greicius
Cassini
Nov. 2, 2015

Dunelands of Titan

Titan
Saturn's frigid moon Titan has some characteristics that are oddly similar to Earth, but still slightly alien. It has clouds, rain and lakes (made of methane and ethane), a solid surface (made of water ice), and vast dune fields (filled with hydrocarbon sands).

The dark, H-shaped area seen here contains two of the dune-filled regions, Fensal (in the north) and Aztlan (to the south).

Cassini's cameras have frequently monitored the surface of Titan (3200 miles or 5150 kilometers across) to look for changes in its features over the course of the mission. Any changes would help scientists better understand different phenomena like winds and dune formation on this strangely earth-like moon.

For a closer view of Fensal-Aztlan, see PIA07732.

This view looks toward the leading side of Titan. North on Titan is up. The image was taken with the Cassini spacecraft narrow-angle camera on July 25, 2015 using a spectral filter sensitive to wavelengths of near-infrared light centered at 938 nanometers.

The view was obtained at a distance of approximately 450,000 miles (730,000 kilometers) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 32 degrees. Image scale is 3 miles (4 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute
Last Updated: Nov. 2, 2015
Editor: Tony Greicius
Cassini
Oct. 30, 2015

Saturn's Geyser Moon Shines in Close Flyby Views

Unprocessed view of Saturn's moon Enceladus
This unprocessed view of Saturn's moon Enceladus was acquired by NASA's Cassini spacecraft during a close flyby of the icy moon on Oct. 28, 2015.
Credits: NASA/JPL-Caltech/Space Science Institute
Enceladus
NASA's Cassini spacecraft captured this view as it neared icy Enceladus for its closest-ever dive past the moon's active south polar region.
Credits: NASA/JPL-Caltech/Space Science Institute
Enceladus
The south polar region of Saturn's active, icy moon Enceladus awaits NASA's Cassini spacecraft in this view, acquired on approach to the mission's deepest-ever dive through the moon's plume of icy spray.
Credits: NASA/JPL-Caltech/Space Science Institute
Enceladus and Saturn's rings
Following a successful close flyby of Enceladus, NASA's Cassini spacecraft captured this artful composition of the icy moon with Saturn's rings beyond.
Credits: NASA/JPL-Caltech/Space Science Institute
Enceladus
During its closest ever dive past the active south polar region of Saturn's moon Enceladus,
Credits: NASA/JPL-Caltech/Space Science Institute

NASA's Cassini spacecraft has begun transmitting its latest images of Saturn's icy, geologically active moon Enceladus, acquired during the dramatic Oct. 28 flyby in which the probe passed about 30 miles (49 kilometers) above the moon's south polar region. The spacecraft will continue transmitting its data from the encounter for the next several days.

"Cassini's stunning images are providing us a quick look at Enceladus from this ultra-close flyby, but some of the most exciting science is yet to come," said Linda Spilker, the mission's project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.

Researchers will soon begin studying data from Cassini's gas analyzer and dust detector instruments, which directly sampled the moon's plume of gas and dust-sized icy particles during the flyby. Those analyses are likely to take several weeks, but should provide important insights about the composition of the global ocean beneath Enceladus' surface and any hydrothermal activity occurring on the ocean floor. The potential for such activity in this small ocean world has made Enceladus a prime target for future exploration in search of habitable environments in the solar system beyond Earth.

In addition to the processed images, unprocessed, or "raw," images appear on the Cassini mission website at:


Cassini's next and final close Enceladus flyby will take place on Dec. 19, when the spacecraft will measure the amount of heat coming from the moon's interior. The flyby will be at an altitude of 3,106 miles (4,999 kilometers).

Additional information and multimedia products for Cassini's final Enceladus flybys are available at:


The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory in Pasadena, California, manages the mission for the agency's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. The Cassini imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about Cassini, visit:


Preston Dyches
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-7013
preston.dyches@jpl.nasa.gov

Dwayne Brown / Laurie Cantillo
NASA Headquarters, Washington
202-358-1726 / 202-358-1077
dwayne.c.brown@nasa.gov / laura.l.cantillo@nasa.gov

2015-337     
Last Updated: Oct. 30, 2015
Editor: Tony Greicius
 
Cassini
Oct. 26, 2011
On Oct. 28, 2015, NASA's Cassini spacecraft will take the deepest dive ever through the plume of Saturn's moon Enceladus.
Artist’s rendering showing a cutaway view into the interior of Saturn’s moon EnceladuA
This artist’s rendering showing a cutaway view into the interior of Saturn’s moon Enceladus. NASA’s Cassini spacecraft discovered the moon has a global ocean and likely hydrothermal activity. A plume of ice particles, water vapor and organic molecules sprays from fractures in the moon's south polar region.
Credits: NASA/JPL-Caltech

NASA's Cassini spacecraft will sample the ocean of Saturn's moon Enceladus on Wednesday, Oct. 28, when it flies through the moon's plume of icy spray.

Cassini launched in 1997 and entered orbit around Saturn in 2004. Since then, it has been studying the huge planet, its rings and its magnetic field. Here are some things to know about the mission's upcoming close flyby of Enceladus:

-- Enceladus is an icy moon of Saturn. Early in its mission, Cassini discovered Enceladus has remarkable geologic activity, including a towering plume of ice, water vapor and organic molecules spraying from its south polar region. Cassini later determined the moon has a global ocean and likely hydrothermal activity, meaning it could have the ingredients needed to support simple life.

-- The flyby will be Cassini's deepest-ever dive through the Enceladus plume, which is thought to come from the ocean below. The spacecraft has flown closer to the surface of Enceladus before, but never this low directly through the active plume.

-- The flyby is not intended to detect life, but it will provide powerful new insights about how habitable the ocean environment is within Enceladus.

-- Cassini scientists are hopeful the flyby will provide insights about how much hydrothermal activity -- that is, chemistry involving rock and hot water -- is occurring within Enceladus. This activity could have important implications for the potential habitability of the ocean for simple forms of life. The critical measurement for these questions is the detection of molecular hydrogen by the spacecraft.

-- Scientists also expect to better understand the chemistry of the plume as a result of the flyby. The low altitude of the encounter is, in part, intended to afford Cassini greater sensitivity to heavier, more massive molecules, including organics, than the spacecraft has observed during previous, higher-altitude passes through the plume.

-- The flyby will help solve the mystery of whether the plume is composed of column-like, individual jets, or sinuous, icy curtain eruptions -- or a combination of both. The answer would make clearer how material is getting to the surface from the ocean below.

-- Researchers are not sure how much icy material the plumes are actually spraying into space. The amount of activity has major implications for how long Enceladus might have been active.

NASA's Cassini spacecraft will sample an extraterrestrial ocean on Wednesday, Oct. 28, when it flies directly through a plume of icy spray coming from Saturn's moon Enceladus. The agency held a news teleconference to discuss plans for and anticipated science results from the historic flyby.
An online toolkit for all three final Enceladus flybys is available at:


The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate in Washington.

For more information about Cassini, visit:


Preston Dyches
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-7013
preston.dyches@jpl.nasa.gov

Dwayne Brown / Laurie Cantillo
NASA Headquarters, Washington
202-358-1726 / 202-358-1077
dwayne.c.brown@nasa.gov / laura.l.cantillo@nasa.gov
2015-328
Last Updated: Oct. 26, 2015
Editor: Tony Greicius
Cassini
Enceladus
Enceladus is a world divided. To the north, the terrain is covered in impact craters, much like other icy moons. But to the south, the record of impact cratering is much more sparse, and instead the land is covered in fractures, ropy or hummocky terrain and long, linear features.

Lit terrain seen here is on the trailing side of Enceladus. North on Enceladus is up. The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on July 27, 2015.

The view was obtained at a distance of approximately 70,000 miles (112,000 kilometers) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 25 degrees. Image scale is 0.4 miles (0.7 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute
Last Updated: Oct. 26, 2015
Editor: Tony Greicius
Cassini
Oct. 19, 2015 

Gored Clump in Saturn's F Ring

Saturn's F ring
Saturn's dynamic F ring contains many different types of features to keep scientists perplexed. In this image we see features ring scientists call "gores," to the right of the bright clump, and a "jet," to the left of the bright spot.

Thanks to the ring's interaction with the moons Prometheus and Pandora, and perhaps a host of smaller moonlets hidden in its core, the F ring is a constantly changing structure, with features that form, fade and re-appear on timescales of hours to days.

This view looks toward the unilluminated side of the rings from about 7 degrees below the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on March 15, 2015.

The view was acquired at a distance of approximately 295,000 miles (475,000 kilometers) from Saturn and at a Sun-ring-spacecraft, or phase, angle of 117  degrees. Image scale is 1.8 miles (2.9 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute
Last Updated: Oct. 19, 2015
Editor: Tony Greicius
Cassini
Mimas and Pandora
Although Mimas and Pandora, shown here, both orbit Saturn, they are very different moons. Pandora, "small" by moon standards (50 miles or 81 kilometers across) is elongated and irregular in shape. Mimas (246 miles or 396 kilometers across), a "medium-sized" moon, formed into a sphere due to self-gravity imposed by its higher mass.

The shapes of moons can teach us much about their history. For example, one explanation for Pandora's elongated shape and low density is that it may have formed by gathering ring particles onto a dense core.

This view looks toward the unilluminated side of the rings from 0.26 degrees below the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 26, 2015.

The view was obtained at a distance of approximately 485,000 miles (781,000 kilometers) from Pandora. Image scale is 3 miles (5 kilometers) per pixel. Mimas is 904,000 miles (1.4 million kilometers) from the spacecraft in this image. The scale on Mimas is 5.4 miles (8.4 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute
Last Updated: Oct. 13, 2015
Editor: Tony Greicius
Cassini
Oct. 5, 2015

Titan's Accent Mark

A coincidence of viewing angle makes Pandora appear to be hovering over Titan, almost like an accent mark.
A coincidence of viewing angle makes Pandora appear to be hovering over Titan, almost like an accent mark.

Little Pandora is much closer to Cassini than hazy Titan in this view. (Titan is nearly three times farther away.) Even so, Titan (3,200 miles or 5,150 kilometers across) dwarfs Pandora (50 miles or 81 kilometers across). This gives us some sense of the diversity in sizes, and shapes, of Saturn's many moons.

North on Titan is up and rotated 19 degrees to the right. The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on July 4, 2015.

The view was acquired at a distance of approximately 1.2 million miles (1.9 million kilometers) from Titan. Image scale is 7 miles (12 kilometers) per pixel on Titan. Pandora is at a distance of 436,000 miles (698,000 kilometers) away from the spacecraft. The scale on Pandora is about 3 miles (4 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.
For more information about the Cassini-Huygens mission visit
The Cassini imaging team homepage is at
Credit: NASA/JPL-Caltech/Space Science Institute
Last Updated: Oct. 5, 2015
Editor: Tony Greicius
Saturn
Sept. 29, 2015

Clouded Worlds

Titan and Saturn
Titan and Saturn have very few things in common, but a hazy appearance is one feature they share. Though they appear similar in this image, appearances can be misleading.

Although both Saturn and Titan (3,200 miles or 5,150 kilometers across) have thick atmospheres and are covered in clouds, their differences are significant. Saturn is a gas giant with no solid surface to speak of. Titan's atmosphere is a blanket surrounding an icy, solid body. Even their atmospheric compositions are different; Saturn is mostly hydrogen and helium with clouds of water and ammonia and ammonium hydrosulfide. Titan's atmosphere is primarily nitrogen with methane clouds.

This view looks toward Saturn from the unilluminated side of the rings, 0.3 degrees below the ring plane. The image was taken in visible green light with the Cassini spacecraft wide-angle camera on May 22, 2015.

The view was obtained at a distance of approximately 1.4 million miles (2.2 million kilometers) from Saturn. Image scale is 81 miles (130 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
The Cassini imaging team homepage is at
Credit: NASA/JPL-Caltech/Space Science Institute
Last Updated: Sept. 29, 2015
Editor: Tony Greicius
Tags:  Cassini, Jet Propulsion Laboratory, Saturn, Solar System,
Solar System and Beyond
Cassini moons
Prometheus and Pandora are almost hidden in Saturn's rings in this image.

Prometheus (53 miles or 86 kilometers across) and Pandora (50 miles or 81 kilometers across) orbit along side Saturn's narrow F ring, which is shaped, in part, by their gravitational influences help to shape that ring. Their proximity to the rings also means that they often lie on the same line of sight as the rings, sometimes making them difficult to spot.

In this image, Prometheus is the left most moon in the ring plane, roughly in the center of the image. Pandora is towards the right.

This view looks toward the unilluminated side of the rings from about 0.3 degrees below the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on May 6, 2015.

The view was obtained at a distance of approximately 994,000 miles (1.6 million kilometers) from Prometheus and at a Sun-Prometheus-spacecraft, or phase, angle of 106 degrees. Image scale is 6 miles (10 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute   
Last Updated: Sept. 22, 2015
Editor: Tony Greicius
Cassini
Saturn and Dione
Why does Saturn look like it's been painted with a dark brush in this infrared image, but Dione looks untouched? Perhaps an artist with very specific tastes in palettes?

The answer is methane. This image was taken in a wavelength that is absorbed by methane. Dark areas seen here on Saturn are regions with thicker clouds, where light has to travel through more methane on its way into and back out of the atmosphere. Since Dione (698 miles or 1,123 kilometers across) doesn't have an atmosphere rich in methane the way Saturn does, it does not experience similar absorption -- the sunlight simply bounces off its icy surface.

Shadows of the rings are seen cast onto the planet at lower right.

This view looks toward Saturn from the unilluminated side of the rings, about 0.3 degrees below the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on May 27, 2015 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 728 nanometers.

The view was acquired at a distance of approximately 618,000 miles (994,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 84 degrees. Image scale is 37 miles (59 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

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

Credit: NASA/JPL-Caltech/Space Science Institute
Last Updated: Sept. 10, 2015
Editor: Tony Greicius
Cassini
Aug. 31, 2015

Entranced by a Transit

Saturn's moon Dione
Saturn's moon Dione crosses the face of the giant planet in this view, a phenomenon astronomers call a transit. Transits play an important role in astronomy and can be used to study the orbits of planets and their atmospheres, both in our solar system and in others.

By carefully timing and observing transits in the Saturn system, like that of Dione (698 miles or 1123 kilometers across), scientists can more precisely determine the orbital parameters  of Saturn’s moons.

This view looks toward the unilluminated side of the rings from about 0.3 degrees below the ring plane. The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on May 21, 2015.

The view was acquired at a distance of approximately 1.4 million miles (2.3 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 119 degrees. Image scale is 9 miles (14 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute 
Last Updated: Aug. 31, 2015
Editor: Tony Greicius
Cassini
Aug. 17, 2015

Chasms on Dione

Saturn's moon Dione
While not bursting with activity like its system sister Enceladus, the surface of Dione is definitely not boring. Some parts of the surface are covered by linear features, called chasmata, which provide dramatic contrast to the round impact craters that typically cover moons.

The bright network of fractures on Dione (698 miles or 1123 kilometers across) was seen originally at poor resolution in Voyager images and was labeled as "wispy terrain." The nature of this terrain was unclear until Cassini showed that they weren't surface deposits of frost, as some had suspected, but rather a pattern of bright icy cliffs among myriad fractures. One possibility is that this stress pattern may be related to Dione's orbital evolution and the effect of tidal stresses over time.

This view looks toward the trailing hemisphere of Dione. North on Dione is up. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on April 11, 2015.

The view was acquired at a distance of approximately 68,000 miles (110,000 kilometers) from Dione. Image scale is 2,200 feet (660 meters) per pixel.


The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute 


Last Updated: Aug. 17, 2015
Editor: Tony Greicius
Cassini
Saturn
Saturn’s unusual appearance in this picture is a result of the planet being imaged via an infrared filter.

Infrared images can help scientists determine the location of clouds in the planet’s atmosphere.  In this image, Cassini’s wide-angle camera used a filter which is especially sensitive to infrared wavelengths that are absorbed by methane.  Methane is not a major component of Saturn’s atmosphere, but enough of it is present to make a difference in how much light is reflected by different clouds. The darker areas reveal clouds that are lower in the atmosphere, therefore under more methane. Bright areas on Saturn are higher altitude clouds. Scientists think that these lower-altitude clouds are in regions where “air” is descending while the higher-altitude clouds are in regions where air is rising. Thus, images like this one can help us map the vertical air movements on Saturn.

This view looks toward the unilluminated side of the rings from less than one degree from the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on May 25, 2015 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 890 nanometers.

The view was acquired at a distance of approximately 930,000 miles (1.5 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 99 degrees. Image scale is 55 miles (89 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute 


Last Updated: Aug. 10, 2015
Editor: Tony Greicius
Cassini
Aug. 4, 2015

Looking Up to the Giant

Saturn, Mimas and Dione
Thanks to the illumination angle, Mimas (right) and Dione (left) appear to be staring up at a giant Saturn looming in the background. 
Although certainly large enough to be noticeable, moons like Mimas (246 miles or 396 kilometers across) and Dione (698 miles or 1123 kilometers across) are tiny compared to Saturn (75,400 miles or 120,700 kilometers across). Even the enormous moon Titan (3,200 miles or 5,150 kilometers across) is dwarfed by the giant planet.
This view looks toward the unilluminated side of the rings from about one degree of the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on May 27, 2015 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 728 nanometers.
The view was obtained at a distance of approximately 634,000 miles (one million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 85 degrees. Image scale is 38 miles (61 kilometers) per pixel.
The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
 The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute 
Last Updated: Aug. 4, 2015
Editor: Tony Greicius
July 27, 2015

Bright Basin on Tethys

Tethys
With the expanded range of colors visible to Cassini's cameras, differences in materials and their textures become apparent that are subtle or unseen in natural color views. Here, the giant impact basin Odysseus on Saturn's moon Tethys stands out brightly from the rest of the illuminated icy crescent. This distinct coloration may result from differences in either the composition or structure of the terrain exposed by the giant impact. Odysseus (280 miles, or 450 kilometers, across) is one of the largest impact craters on Saturn's icy moons, and may have significantly altered the geologic history of Tethys.

Tethys' dark side (at right) is faintly illuminated by reflected light from Saturn.

Images taken using ultraviolet, green and infrared spectral filters were combined to create this color view. North on Tethys (660 miles or 1,062 kilometers across) is up in this view.

The view was acquired on May 9, 2015 at a distance of approximately 186,000 miles (300,000 kilometers) from Tethys. Image scale is 1.1 mile (1.8 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute 

Last Updated: July 30, 2015
Editor: Tony Greicius
Dione
July 20, 2015

Mother and Daughter

Saturn moons Dione and Tethys
In Greek mythology, Dione was the daughter of Tethys, so we should perhaps not be surprised to see the two eponymous moons together.

In reality, the moons Tethys (660 miles or 1062 kilometers across) and Dione (698 miles or 1123 kilometers across) are not mother and daughter in any sense. They are perhaps more like sisters since scientists believe that they formed out of the same disk around an early Saturn.

Dione in this image is the upper moon, while Tethys is the lower.

This view looks toward the anti-Saturn side of Dione. North on Dione is to the right. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on April 4, 2015.

The view was obtained at a distance of approximately 1.5 million miles (2.4 million kilometers) from Dione. Image scale is 9 miles (14 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (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. 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, Colorado.

For more information about the Cassini-Huygens mission visit
 or http://www.nasa.gov/cassini . The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute 
Caption updated July 22, 2015 to correct the stated orientation of north.
Last Updated: July 30, 2015
Editor: Tony Greicius
Saturn
June 29, 2015

Spirals in the D Ring

Saturn rings
Although the D ring of Saturn is so thin that it's barely noticeable compared to the rest of the ring system, it still displays structures seen in other Saturnian rings. Here the spiral structures in the D ring are on display.

The D ring spirals, discovered in Cassini images, are believed to be due to a warp in the ring created in the early 1980s. The precise mechanism remains the subject of scientific debate.  Over the course of the Cassini mission, scientists have been able to observe the spiral winding ever more tightly as it evolves. For more about the spiral, see PIA12820 and PIA08325.

 (The bright specks and faint vertical streaks are merely image artifacts.  The processes typically employed to remove these artifacts would also have degraded the exquisite details of the D ring which are visible here.)

This view looks toward the sunlit side of the rings from about 22 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 6, 2013.

The view was acquired at a distance of approximately 350,000 miles (563,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 131  degrees. Image scale is 2.1 miles (3.4 kilometers) per pixel.

For more information about the Cassini-Huygens mission visit
The Cassini imaging team homepage is at

Credit: NASA/JPL-Caltech/Space Science Institute
Last Updated: July 30, 2015
Editor: Tony Greicius
NASA
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