Titan. In color.
Posted by J. Major
Color-composite raw image of Titan, captured Jan. 30. (NASA/JPL/SSI/J. Major)
On Jan. 30, the Cassini spacecraft executed a flyby maneuver of Titan, Saturn’s largest moon, passing within 19,340 miles (31,130 km) of its surface.
This color composite image of the cloud-covered moon was created by combining raw data acquired with Cassini’s Imaging Science System (ISS) in red, green, blue and clear color channels. The result is the image above, approximating what the human eye might see… albeit the “real” view would appear much dimmer due to the low levels of light at that distance from the Sun.
The dark areas are vast hydrocarbon dune fields known as “Shangri-La”.
Posted in Saturn's Moons
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From the LITD Archives: Eclipsing Mimas
Posted by J. Major
Originally published on May 16, 2009. LITD is almost 3 years old!
A Shadow Crosses the Face of Mimas
This animation, made from a series of 8 raw images taken by Cassini on May 14, shows Saturn’s moon Mimas being eclipsed by another object…..a neighboring moon, perhaps? It’s not mentioned, but it definitely seems to be something of similar size, and round.
Mimas is best characterized by its large-scale Herschel crater in its northern hemisphere. At 88 miles wide, it is a major surface feature of the 246-mile-wide moon (and pretty much makes it look like a rough version of the Death Star.) Herschel is not visible in these particular images.
It will be interesting to see if this eclipse event is clarified by the Cassini mission team in the future.
Raw image credit: NASA/JPL/Space Science Institute. Animation: J. Major.
Posted in Saturn's Moons
The Colors of Titan’s Sky
Posted by J. Major
Color-composite image of backlit Titan. (NASA/JPL/SSI/J.Major)
Made from one of the most recent Cassini images, this is a color-composite showing a backlit Titan with its dense, multi-layered atmosphere scattering sunlight in different colors. Titan’s atmosphere is made up of methane and complex hydrocarbons and is ten times as thick as Earth’s. It is the only moon in our solar system known to have a substantial atmosphere.
Titan’s high-level hydrocarbon haze is nicely visible as a pale blue band encircling the moon.
Posted in Saturn's Moons
Saturn’s Spooky Sounds
Posted by J. Major
No video below? Click here.
Here’s a bit of space spookiness just in time for the Halloween season! It’s a recording of the intense radio emissions coming from Saturn, as detected by the Cassini spacecraft’s radio and plasma wave science instrument on November 22, 2003.
Not exactly a direct audio recording (since Cassini is in space where there’s no “sound” like we hear) these eerie sounds are tonal interpretations of Saturn’s fluctuating radio emissions, which are closely related to the planet’s auroral activity. The frequencies have been shifted downwards by a factor of 44 to make them audible to our ears.
Time on this recording has been compressed, so that 73 seconds corresponds to 27 minutes.
Sounds eerily like the effects from an old “B” sci-fi movie! All we need now are the bug-eyed alien zombies…
Read more about this recording here.
Fantastic Four
Posted by J. Major
Latest Cassini image shows four of Saturn's moons
New image from Cassini and the CICLOPS imaging team shows Titan, Dione, Pan and Pandora in the same shot!
Pan is furthest to the left, a tiny moon tucked into the gap in the rings. Dione hovers in front of the cloud-covered Titan, and Pandora is the football-shaped moon just outside the edge of the F ring at right.
Just a few of the many and varied satellites that orbit Saturn!
Credit: NASA/JPL/SSI
Latest Images of Enceladus
Posted by J. Major
Enceladus' ice plumes in action are best seen from its night side.
On Saturday, Oct. 1, the Cassini spacecraft performed another flyby of Saturn’s moon Enceladus. Passing by at a distance of only 62 miles (99 km) Cassini took some fantastic images of the 318-mile-wide moon — most notably of its signature plumes of water ice spraying from fissures along its south pole!
Posted in Saturn's Moons
Moons of Three
Posted by J. Major
The moons of Saturn are as beautiful as they are varied...
Saturn’s moons Dione and Titan lined up with the planet’s rings, seen here nearly edge-on, from the point of view of the Cassini spacecraft’s camera on September 17, 2011.
This is a composite of three raw images taken with Cassini’s red, green and blue visible-light clear filters.
Dione, 700 miles wide, is dwarfed by the much larger and further moon Titan, which is over 3,200 miles wide and wrapped in a thick opaque atmosphere.
Also in this image is the 12-mile-wide shepherd moon Pan, barely visible within the Encke Gap in the A ring, just below and to the left of Dione.
Cassini was about 1.33 million miles away from Dione when this view was acquired.
Credit: NASA / JPL / SSI. Edited by Jason Major.
See more scenes from Saturn on the Cassini Imaging Team’s website.
High Over Hyperion
Posted by J. Major
A dramatically-lit look at the cratered surface of Hyperion
The Cassini spacecraft passed by Saturn’s spongy-looking moon Hyperion yesterday, August 25, and returned some very dramatic images like the one seen here – fascinating! At 15,000 miles this was Cassini’s second-closest approach to Hyperion.
It will pass by again on September 16 at just over twice that distance. The closest it has come to Hyperion was 310 miles on September 26, 2005.
The heavily cratered Hyperion is about 168 miles wide. It resides in an orbit between Titan and Iapetus, and is Saturn’s largest irregularly-shaped moon… in fact, the largest such moon in the solar system.
Image has been rotated 180º and adjusted to enhance detail from the original raw image.
Credit: NASA / JPL / Space Science Institute. Edited by J. Major.
Daphnis in Full Color
Posted by J. Major
Color-calibrated image of Daphnis and Saturn's rings by Gordan Ugarkovic
If you’ve been following along with Lights in the Dark since the beginning, you may know that this is one of my favorite subjects of space imagery: the shepherd moon Daphnis, traveling in its orbit around Saturn within the 26-mile-wide Keeler Gap. Recently color-calibrated by Gordan Ugarvovic, this is a true-color version of an image captured by Cassini on July 5, 2010. It was Cassini’s closest approach to the 4.5-mile-wide moon.
What makes Daphnis so interesting is its effect on the edges of the gap. As it travels its gravity affects the icy bits of ring material, churning them up into waves and scalloped edges before andbehind it. These waves can rise up considerably into peaks and valleys, some reaching over a mile or two above the ring plane! Now that would be quite a dramatic sight to see close-up!
This is a great color version of an image I posted about shortly after it was first acquired. A new image from Gordan is always a treat!
Image: NASA / JPL / Space Science Institute / Gordan Ugarkovic
Posted in Saturn, Saturn's Moons
Here’s a color-composite image of Saturn’s two-toned moon Iapetus; its Saturn-facing light side is seen here facing to the lower left.
More Hope for Life on Enceladus?
Posted by J. Major
Enceladus' signature ice geysers in action. NASA / JPL / SSI
Researchers on the Cassini mission team have identified large salt grains in the plumes emanating from Saturn’s icy satellite Enceladus, making an even stronger case for the existence of a salty liquid ocean beneath the moon’s frozen surface.
Posted in Saturn's Moons
Moon Noir
Posted by J. Major
Helene's just hanging out...
Here’s another intriguing look at Helene, lit by sunlight from the right while some reflected light from its own highlands illuminates the interior of a valley/crater. Its dark side appears pitch black against the slightly brighter region of space behind, possibly lightened by the diffuse reflected light from ice particles in Saturn orbit.
This is from a raw image acquired by Cassini as it was approaching Helene on June 18, 2011. For more information on that flyby, see my previous post.
I brightened the image a bit so it would be more visible on most monitors, and added a layer to give a slight glow effect from the sunlit area. I also had to clean up some CCD noise and artifacting around the edges of the moon. The original downlink can be seen here.
Credit: NASA / JPL / SSI. Edited by J. Major.
A Close Pass of Helene
Posted by J. Major
Color composite of Helene from June 18, 2011
On June 18, 2011, the Cassini spacecraft performed a flyby of Saturn’s moon Helene. Passing at a distance of 4,330 miles, it was its second-closest pass of the icy little moon.
Big Sisters
Posted by J. Major
Saturn's two largest moons, Rhea and Titan
Here’s a color-composite image of Rhea and Titan, Saturn’s largest moons. Made from raw images acquired by the Cassini spacecraft on June 16, 2011, this really shows the vast difference in size and appearance of the two moons.
Rhea, seen in the foreground, is an icy, airless and heavily-cratered world 950 miles wide. Titan, on the other hand, is over three times larger at 3,200 miles across and covered in a thick atmosphere of methane and hydrocarbons. Its surface features mountains and valleys, with lakes and streams of liquid methane… and it may even have a liquid subsurface ocean.
Titan’s atmosphere and high-level haze can be seen in this image, and you can also see where the moon’s shadow cuts through the haze at the south pole (up and to the right in this image.)
Raw images taken in red, green and blue visible-light channels were combined to make this color version. The spacecraft was 1,828,949 km (1,136,456 miles) from Rhea when the images were taken.
Credit: NASA / JPL / Space Science Institute. Edited by Jason Major.
Posted in Saturn's Moons
Look on the Bright Side
Posted by J. Major
Here’s a color-composite image of Saturn’s two-toned moon Iapetus; its Saturn-facing light side is seen here facing to the lower left.
Iapetus is 1,471 km (914 miles) wide.
The raw images were taken by the Cassini spacecraft on June 6, 2011 and received on Earth June 8, 2011. The camera was pointing toward Iapetus from approximately 871,021 kilometers (541,227 miles) away.
Credit: NASA / JPL / SSI / J. Major.
Posted in Saturn's Moons
Big Moon, Small Moon
Titan and Dione are seen together in front of Saturn's rings and night side limb. Color-composited from Cassini raw images acquired on May 21, 2011. Credit: NASA / JPL / SSI / J. Major.
A Fistful of Moons
Posted by J. Major
Cassini caught five moons in one image on January 11, 2011
This image from Cassini shows no less than five of Saturn’s moons in the same frame: Rhea (1,528 kilometers, or 949 miles across) is largest in the foreground; Dione (1,123 kilometers, or 698 miles across) can be seen just above the rings below Rhea near the center; Prometheus (86 kilometers, or 53 miles across) is just barely visible in the rings to the right of Dione; Epimetheus (113 kilometers, or 70 miles across) is to the right of the rings and Tethys (1,062 kilometers, or 660 miles across) is on the extreme right below the ringplane.
Cassini was approximately 61,000 km (38,000 miles) from Rhea when this image was acquired.
Read more on the Cassini mission site here.
Credit: NASA / JPL / Space Science Institute
Posted in Saturn's Moons
A Fan of Shadows
Posted by J. Major
Clumped material in Saturn's F ring casts a spread of linear shadows
Cassini captured this visible-light image on October 16, 2010, showing a thick clump of icy material in Saturn’s bright F ring casting a “fan” of thin shadows. Clumps like this have been seen many times before and may be caused by the gravitational effects of passing shepherd moons like Prometheus or as-of-yet undiscovered moonlets within the ropy rings themselves.
Click here to see how the 63-mile-wide Prometheus can pull streamers of the F ring away as it dips in and out along the course of its scalloped orbit.
Positioned just outside the extreme outer edge of Saturn’s A ring system, the F ring is made up of very bright particles of ice loosely organized into ropy strands and transient clumps. It ranges anywhere from 20 to 300 miles wide.
Image: NASA / JPL / Space Science Institute
Posted in Saturn
From the LITD Archives: A Primordial Moon
Posted by J. Major
Phoebe
A beautiful Cassini color-composite by Gordan Ugarkovic, this false-color image shows the ancient and heavily-cratered surface of Saturn’s moon Phoebe.
Irregularly-shaped and bout 132 miles across, Phoebe is a fifteenth the size of our own moon but is believed to be much, much older. With its retrograde (backwards) orbit, high orbital incline and extremely dark, pitted surface, it’s believed that Phoebe was once a “Centaur” – a Kuiper Beltobject that has been captured by Saturn’s gravity and adopted as a permanent member of the family.
Kuiper Belt Objects (KBOs) are small rock-and-ice worlds that orbit the sun in the far reaches of the solar system. They are primordial remnants from the early days of the solar system, chunks of dark material that never coalesced into larger worlds or changed their chemical structure by solar heating. Centaurs are the term for Kuiper Belt Objects that have drifted into the inner solar system.
Phoebe orbits Saturn at a distance of over 8 million miles (nearly 13 million km).
Image credit: NASA/JPL/SSI/Gordan Ugarkovic
(Originally posted on March 20, 2009)
Posted in Repost, Saturn's Moons
