This is one of the tiny moons of Saturn seen up close around Jan 27, 2010 by Cassini. In case you do not recall, it is the moon responsible for some of the best ring disturbance movies of the mission.

Prometheus is the small moon that shepherds Saturn’s outer “F” ring and causes those crazy waves in the particles that make up the ring itself. The phenomenon has been the theme of at least 3 different animations here on wanderingspace.net. The image above is what that small moon in those animations looks like from 60,000 km taken by Cassini on Dec 26, 2009.

Recent observations of Saturn’s rings from Cassini reveal some vertical structure to the rings. Shown here are disturbances caused by Daphnis, a small moonlet that orbits within the Keeler Gap of the rings. We have seen much of these kinds of disturbances in the rings from tiny moonlets, but the Saturninan equinox finally provides us with an angle of sunlight that reveals such structures from the long shadows they cast. The tallest shadow seen at right is Daphnis itself.

Some recent posts from Gordan Ugarkovic. The first is just gorgeous, the second featuring Prometheus and Pan in the gaps, the third is also just real pretty and the 4th is two sides of Enceladus. The 2nd and 4th of these images are false color which we publish less often, but these were just too nice to deny.

Yes, another movie of Prometheus disturbing Saturn’s rings. This is the longest clip and includes the most ring swinging action for your money. This version has been cropped and reduced down from the original. See here for a larger, wider view of the same animation (2M gif).

Janus is a minor moon of Saturn. Seen here by Cassini from 32,967 km.

From the raw images of the Cassini mission. This is Saturn’s tiny moon Prometheus causing a disturbance in some ring particles. Nothing really new to be said here as we have seen this featured in a few animations posted here before. This is just a nice image of that phenomenon with the addition of a nice glaringly over-exposed Prometheus.

Prometheus disturbing the F-Ring as it passes. We have seen this animated before, but perhaps not from such a vantage point.

This improved image of Epimetheus was released to the Cassini site yesterday and as compared to this more raw image post from December 8, it is most notably cleaner, processed in color and appears to be much sharper.

This is a view of the moon’s more southern pole and there is speculation that covering a majority of this face is actually one large impact crater which could explain it’s flattened appearance. There also seems to be what looks like a deposit or “dusting” of material all over this face which seems to blanket flat areas and begins to fill some craters and other depressed regions. The moon is only about 70 x 50 km in size, approximately the size of a city such as Los Angeles.

A new look at a minor Saturn moon Epimetheus. Image credit is Ian Regan, the same creator of this super awesome Saturn image.

There have been some nice NASA animations of the interaction between some “shepard” moons and the rings, but this has to be the most impressive. There are some blank frames in there for gaps in the data… but the effect is still easy to follow.

NASA released an unusually large amount of color images to the Cassini website recently. Most of what is shown here on this site are actually images put together by freelance imagers who access the raw files and do some stitching together of filtered images. Color images coming straight off the Cassini website are a rare event, so when about 8 appeared in the gallery a few days ago… it was an unexpected gift.

Saturn as seen from the unlit side of the rings.

A family portrait of the Saturn System. Moons visible in this image (you need to click the preview) are Dione at far left, Enceladus near the left side ring edge, Mimas a speck on ring shadows on the western limb, Rhea against the northern hemisphere, Tethys near the right ring edge, and Titan near lower right.

Titan and a small moonlet named Epimetheus share the frame with Saturn’s rings.

A rare color view of both Saturn and Titan in one frame. This is the only one of its kind thus far in the mission.

A small rainbow appears as sunlight streams through Saturn’s rings.

I tend to not get many of the small bodies in here simply due to the fact that they tend to not be geologically active, are grey in color and lack the grandeur of size. But here is a tiny moon that orbits just outside Saturn’s A-ring and is only about 40 by 20 kilometers in size. What makes this tiny body notable to me, is its shape which many assume is due to the collection of ring particles upon its surface.

As the rings of Saturn are so very flat, the materials all appear to have collected all along Atlas’s equator and as this material piles up it elongates the shape of the moon. This has erased any craters that may have existed on the tiny moon and created one of the Solar System’s more unusual surface features. The piled up equator of Atlas looks more like it is covered with snow and has ultimately given us our first naturally formed flying saucer (see inset side view). You can almost see the truly original form of Atlas somewhere in the middle hidden by the massive amounts of “ring-fall” over its many ages.

Gordan Ugarkovic has a great collection of reworked Cassini images on Flickr. I contacted Gordan about showing some of his images here on wanderingspace and he was ever so gracious. As many people Gordan is “somewhat underwhelmed by the frequency the Cassini Imaging Team releases color composites”, so it is up to excellent freelancers like him to compile this information from the data files which are made public by NASA. Problem is that these images rarely make it to the mass media and we are stuck with the dozen or so color images the NASA imaging teams decide to produce in a year.

WALLPAPER NOTE: The left 1/3 of the “Three Moons” image was extended in Photoshop using data at the edges of the original image which was cropped to a square format. This “fake” imagery was only applied to that area of the rings and the rest of the image including the moons is actual.

Here are some other images from Gordan which are some of my favorites, but don’t trust my editing… go to the gallery and have a look yourself. For the sake of posterity I have added a permanent link to his gallery on the right side of this blog where you may note that there are already a few others linked. There were two additional ones but the sites have been taken down since I linked to them?! Hopefully the three left will stick around for a while and I will in time add more to the collection.

Tethys and Saturn’s Hazy Limb

Mimas and Prometheus on Rings

Io on Jupiters Edge

A tiny moon named Janus with a back drop of Saturn’s cloud-tops. There is not much to say about this tiny place other than the odd nature of its shared orbit with another tiny moon named Epimetheus. About once every four years they approach one another and swap orbits without coming any closer than 10,000km.

IMAGE NOTE: The image original was black and white and color was added based upon numerous images of Saturn’s cloud-tops. As with many tiny moons, the black and white nature of Janus was just maintained as it is not expected to have looked any different in color.