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Seasons of Ice and Shadow
Cassini at Saturn - 2007 Double-size Wall Calendar

Since I couldn't find a decent Cassini wall calendar, I decided to make my own. Click on the thumbnail at right for a larger preview of the entire calendar. For each of the months below, you can click on the large thumbnail to see a quarter-size preview of the actual calendar page, or the small thumbnail to see the original image at NASA's Planetary Photo Journal.

Notes:

  • The images have been cropped and rotated where necessary to fit the calendar format. In some cases the colors have been tweaked to bring out them dimmer details in print.
  • The actual calendar is printed in full color at 200dpi (3500 x 2300 pixels), on 100 lb cover weight high gloss paper and wire-bound. Each page Measure 17" x 11", Measures 17" x 22" when hung on wall.
  • CafePress prints on-demand using an automated process. If there is any problem with the print quality, contact their help desk for immediate replacement.
Cover: The Face of Beauty
PIA07772: Few sights in the solar system are more strikingly beautiful than softly hued Saturn embraced by the shadows of its stately rings.

Few sights in the solar system are more strikingly beautiful than softly The gas planet's subtle northward gradation from gold to azure is a striking visual effect that scientists don't fully understand. Current thinking says that it may be related to seasonal influences, tied to the cold temperatures in the northern (winter) hemisphere. Despite Cassini's revelations, Saturn remains a world of mystery.

Currently, the rings' shadows shield the mid-northern latitudes from the harshest of the sun's rays. As Saturn travels around the sun in its 29-year orbit, the shadows will narrow and head southward, eventually blanketing the opposite hemisphere.

Images taken with blue, green and red spectral filters were used to create this color view, which approximates the scene as it would appear to the human eye. The view was brightened to enhance detail visible in the rings and within their shadows.

The images were obtained with the Cassini wide-angle camera from a distance of approximately 999,000 kilometers (621,000 miles) from Saturn on May 4, 2005, as the spacecraft cruised a few degrees above the ring plane. The image scale is about 60 kilometers (37 miles) per pixel on Saturn.

Image and Text Credit: NASA/JPL/Space Science Institute
 

January: Dazzling Color
PIA07771: Cool and icy Dione floats in front of giant Saturn bedecked in a dazzling array of colors.

The surface of Dione, which exhibits contrasting bright and dark areas when viewed up close, appears pale in this image. It is Saturn's multi-hued cloud bands that boldly steal the show. Discrete clouds and eddies in Saturn's northern hemisphere can be seen within the faint shadows of the rings on the planet. Dione is 1,118 kilometers (695 miles) across.

Cassini is in a phase of its mission in which its orbit will be nearly equatorial for some time. This view was obtained from about one-third of a degree out of the ring plane.

Images taken with red, green and blue filters were used to create this natural-color view. The images were obtained with the wide-angle camera on Sept. 22, 2005, from a distance of approximately 803,000 kilometers (499,000 miles) from Dione and at a sun-Dione-spacecraft, or phase, angle of about 43 degrees. The image scale is about 48 kilometers (30 miles) per pixel.

Image and Text Credit: NASA/JPL/Space Science Institute
 

February: Icy Crescent

PIA07745: As it departed its encounter with Saturn's moon Dione, Cassini sailed above an unreal landscape blasted by impacts. The rising Sun throws craters into sharp contrast and reveals steep crater walls.

At the far right [below, closeup on calendar at right], a medium-sized crater is bisected by a fracture, revealing a cross section of the impact site.

Icy Crescent

The seven clear-filter images in this mosaic were taken with the Cassini spacecraft narrow-angle camera on Oct. 11, 2005, at distances ranging from of 21,650 to 25,580 kilometers (13,450 to 15,890 miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 154 degrees. Resolution in the original images ranges from 126 to 154 meters (413 to 505 feet) per pixel. The images have been re-sized to have an image scale of about 100 meters (330 feet) per pixel. North on Dione is 140 degrees to the left.

Image and Text Credit: NASA/JPL/Space Science Institute
 

March: Colorful Division
PIA08306: The rings are awash in subtle tones of gold and cream in this view which shows the outer B ring, the Cassini Division and the inner part of the A ring.

The rings are awash in subtle tones of gold and cream in this view which shows the outer B ring, the Cassini Division and the inner part of the A ringIn this viewing geometry, the brightest feature in the Cassini Division is the recently discovered diffuse ringlet near the outer edge of the Division (see also PIA08330). The diffuse ringlet has a distinctive bluish cast.

The color of the rings appears more golden than earlier in the mission because of the viewing geometry here -- increased scattering in the rings is brought about by the high phase angle and the view being toward the rings' unlit side.

This view looks toward the unlit side of the rings from about 30 degrees above the ringplane.

Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were acquired by the Cassini spacecraft narrow-angle camera on Sept. 29, 2006 at a distance of approximately 1.829 million kilometers (1.137 million miles) from Saturn. Image scale is 11 kilometers (7 miles) per pixel.

Image and Text Credit: NASA/JPL/Space Science Institute
 

April: Saturn's Subtle Spectrum
PIA08166: Dreamy colors ranging from pale rose to butterscotch to sapphire give this utterly inhospitable gas planet a romantic appeal.

Dreamy colors ranging from pale rose to butterscotch to sapphire give this utterly inhospitable gas planet a romantic appeal. Shadows of the rings caress the northern latitudes whose blue color is presumed to be a seasonal effectShadows of the rings caress the northern latitudes whose blue color is presumed to be a seasonal effect.

Enceladus (505 kilometers, or 314 miles across) hugs the ringplane near the center of the picture.

Images taken using red, green and blue spectral filters were combined to create this color view, which approximates what the human eye would see. The image was taken with the Cassini spacecraft wide-angle camera on March 16, 2006 at a distance of approximately 2.1 million kilometers (1.3 million miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 102 degrees. Image scale is 120 kilometers (75 miles) per pixel on Saturn.

Image and Text Credit: NASA/JPL/Space Science Institute
 

May: Ringside with Dione
PIA07744: Speeding toward pale, icy Dione, Cassini's view is enriched by the tranquil gold and blue hues of Saturn in the distance.

Ringside with DioneThe horizontal stripes near the bottom of the image are Saturn's rings. The spacecraft was nearly in the plane of the rings when the images were taken, thinning them by perspective and masking their awesome scale. The thin, curving shadows of the C ring and part of the B ring adorn the northern latitudes visible here, a reminder of the rings' grandeur.

It is notable that Dione, like most of the other icy Saturnian satellites, looks no different in natural color than in monochrome images.

Images taken on Oct. 11, 2005, with blue, green and infrared (centered at 752 nanometers) spectral filters were used to create this color view, which approximates the scene as it would appear to the human eye. The images were obtained with the Cassini spacecraft wide-angle camera at a distance of approximately 39,000 kilometers (24,200 miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 22 degrees. The image scale is about 2 kilometers (1 mile) per pixel.

Image and Text Credit: NASA/JPL/Space Science Institute
 
 

June: Golden Night on Saturn
PIA08304: Saturn's B and C rings shine in diffuse, scattered light as the Cassini spacecraft looks on the planet's night side.

Saturn's fine, innermost rings are seen silhouetted against the southern hemisphere of the planet before partially disappearing into shadowThe southern hemisphere is lit by sunlight reflecting off the rings, while the north shines much more feebly in the dim light that filters through the rings and is scattered on the northern hemisphere.

The fine, innermost rings are seen silhouetted against the southern hemisphere of the planet before partially disappearing into shadow.

The color of the rings appears more golden because of the increased scattering in the rings brought about by the high phase angle and the view being toward rings' the unlit side. Saturn also looks more golden because of the high phase angle here.

Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were obtained by the Cassini spacecraft wide-angle camera on Sept. 28, 2006 at a distance of approximately 1.4 million kilometers (900,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 151 degrees. Image scale is 83 kilometers (51 miles) per pixel.

Image and Text Credit: NASA/JPL/Space Science Institute
 

July: Zooming In On Enceladus (Mosaic)
PIA06254: As it swooped past the south pole of Saturn's moon Enceladus on July 14, 2005, Cassini acquired high resolution views of this puzzling ice world. From afar, Enceladus exhibits a bizarre mixture of softened craters and complex, fractured terrains.

Enceladus the StorytellerThis large mosaic of 21 narrow-angle camera images have been arranged to provide a full-disk view of the anti-Saturn hemisphere on Enceladus. This mosaic is a false-color view that includes images taken at wavelengths from the ultraviolet to the infrared portion of the spectrum, and is similar to another, lower resolution false-color view obtained during the flyby (see PIA06249). In false-color, many long fractures on Enceladus exhibit a pronounced difference in color (represented here in blue) from the surrounding terrain.

A leading explanation for the difference in color is that the walls of the fractures expose outcrops of coarse-grained ice that are free of the powdery surface materials that mantle flat-lying surfaces.

The original images in the false-color mosaic range in resolution from 350 to 67 meters (1,148 to 220 feet) per pixel and were taken at distances ranging from 61,300 to 11,100 kilometers (38,090 to 6,897 miles) from Enceladus. The mosaic is also part of a movie sequence of images from this flyby (see PIA06253).

Image and Text Credit: NASA/JPL/Space Science Institute
 

August: Fish-eye View of Titan's Surface

PIA08114 This picture is a stereographic (fish-eye) projection taken with the descent imager/spectral radiometer onboard the European Space Agency's Huygens probe, Fish-eye View of Titan's Surfacewhen the probe was about 5 kilometers (3 miles) above Titan's surface. The images were taken on Jan. 14, 2005.

The Huygens probe was delivered to Saturn's moon Titan by the Cassini spacecraft, which is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif. NASA supplied two instruments on the probe, the descent imager/spectral radiometer and the gas chromatograph mass spectrometer.

Image and Text Credit: NASA/JPL/Space Science Institute
 

September: Nature's Canvas
PIA06142: In a splendid portrait created by light and gravity, Saturn's lonely moon Mimas is seen against the cool, blue-streaked backdrop of Saturn's northern hemisphere.

Nature's CanvasDelicate shadows cast by the rings arc gracefully across the planet, fading into darkness on Saturn's night side.

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

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

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

Image and Text Credit: NASA/JPL/Space Science Institute
 

October: Odd World
PIA07740: This stunning false-color view of Saturn's moon Hyperion reveals crisp details across the strange, tumbling moon's surface.

Odd WorldDifferences in color could represent differences in the composition of surface materials. The view was obtained during Cassini's close flyby on Sept. 26, 2005.

Hyperion has a notably reddish tint when viewed in natural color. The red color was toned down in this false-color view, and the other hues were enhanced, in order to make more subtle color variations across Hyperion's surface more apparent.

Images taken using infrared, green and ultraviolet spectral filters were combined to create this view. The images were taken with the Cassini spacecraft's narrow-angle camera at a distance of approximately 62,000 kilometers (38,500 miles) from Hyperion and at a Sun-Hyperion-spacecraft, or phase, angle of 52 degrees. The image scale is 362 meters (1,200 feet) per pixel.

Image and Text Credit: NASA/JPL/Space Science Institute
 

November: Shadow and Shade
PIA08271: This moody true color portrait of Saturn shows a world that can, at times, seem as serene and peaceful as it is frigid and hostile.

Shadow and ShadeSaturn's unlit-side rings embrace the planet while their shadows caress the northern hemisphere.

Janus (181 kilometers, or 113 miles across) is a mere speck below the rings, just left of the terminator. The view was obtained from about 15 degrees above the ringplane as Cassini continued its climb to higher orbital inclinations.

Images taken using red, green and blue spectral filters were combined to create this natural color view. The image was acquired with the Cassini spacecraft wide-angle camera on Aug. 18, 2006 at a distance of approximately 1.3 million kilometers (800,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 137 degrees. Image scale is 76 kilometers (47 miles) per pixel.

Image and Text Credit: NASA/JPL/Space Science Institute
 

December: In Saturn's Shadow
PIA08329: With giant Saturn hanging in the blackness and sheltering Cassini from the sun's blinding glare, the spacecraft viewed the rings as never before, revealing previously unknown faint rings and even glimpsing its home world.

In Saturn's ShadowThis marvelous panoramic view was created by combining a total of 165 images taken by the Cassini wide-angle camera over nearly three hours on Sept. 15, 2006. The full mosaic consists of three rows of nine wide-angle camera footprints; only a portion of the full mosaic is shown here. Color in the view was created by digitally compositing ultraviolet, infrared and clear filter images and was then adjusted to resemble natural color.

Interior to the G ring and above the brighter main rings is the pale dot of Earth. Cassini views its point of origin from over a billion kilometers (and close to a billion miles) away in the icy depths of the outer solar system. See PIA08324 for a similar view of Earth taken during this observation.

In this  version of the mosaic the color contrast is greatly exaggerated. In such views, imaging scientists have noticed color variations across the diffuse rings that imply active processes sort the particles in the ring according to their sizes.

Looking at the E ring in this color-exaggerated view, the distribution of color across and along the ring appears to be different between the right side and the left. Scientists are not sure yet how to explain these differences, though the difference in phase angle between right and left may be part of the explanation. The phase angle is about 179 degrees on Saturn.

The main rings are overexposed in a few places.

The mosaic images were acquired as the spacecraft drifted in the darkness of Saturn's shadow for about 12 hours, allowing a multitude of unique observations of the microscopic particles that compose Saturn's faint rings.

Ring structures containing these tiny particles brighten substantially at high phase angles: i.e., viewing angles where the sun is almost directly behind the objects being imaged.

During this period of observation Cassini detected two new faint rings: one coincident with the shared orbit of the moons Janus and Epimetheus, and another coincident with Pallene's orbit. (See PIA08322 and PIA08328 for more on the two new rings.)

The narrowly confined G ring is easily seen here, outside the bright main rings. Encircling the entire system is the much more extended E ring. The icy plumes of Enceladus, whose eruptions supply the E ring particles, betray the moon's position in the E ring's left-side edge.

This view looks toward the unlit side of the rings from about 15 degrees above the ringplane.

Cassini was approximately 2.2 million kilometers (1.3 million miles) from Saturn when the images in this mosaic were taken. Image scale on Saturn is about 260 kilometers (162 miles) per pixel.

Image and Text Credit: NASA/JPL/Space Science Institute
 

About Cassini
Artists's Conception of Cassini Saturn Orbit Insertion (PIA03883)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, Colorado.

PIA03883: Cassini's Saturn Orbit Insertion. This is an artists concept of Cassini during the Saturn Orbit Insertion (SOI) maneuver on July 1, 2004, just after the main engine began firing. The spacecraft is moving out of the plane of the page and to the right (firing to reduce its spacecraft velocity with respect to Saturn) and has just crossed the ring plane.

The SOI maneuver, which was approximately 90 minutes long, allowed Cassini to be captured by Saturn's gravity into a five-month orbit. Cassini's close proximity to the planet after the maneuver offered a unique opportunity to observe Saturn and its rings at extremely high resolution.

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

Image and Text Credit: NASA/JPL/Space Science Institute
 

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