Starship Asterisk*

[i]Umbriel (2013 version) Credit: NASA / JPL / Ted Stryk This view of Umbriel was composed by stacking Voyager 2's best two images of it, and coloring it using images taken from a greater distance.[/i]

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Umbriel, a moon of Uranus, is about 1200 kilometers across. It is less reflective than the planet's other moons, except for mysterious bright features: one seen on the rim of what appears to be a crater, and the central peak of another. It was imaged by Voyager 2 in January of 1986, at a resolution of 10 kilometers per pixel in the two images snapped at closest approach. Unfortunately, one of the images was underexposed and slightly smeared, and the other was properly exposed but very smeared.

My processing of the images a few years ago, which can be seen here, was focused around desmearing and bringing out detail. This is all well and good, but the artifacts from such processing made it, well, ugly. While there are other views that include more images and were less smeared/underexposed, they were much more distant, making them frustratingly small. I decided to start from scratch, reprocessing the two highest resolution frames, combining them at 125% of their original size, and creating a color overlay from more distant images. Having refined some of the techniques I used in 2009 and trying to avoid overextending the processing, I have created a version that is much more beautiful and perhaps gives us an idea what Umbriel really looks like.

Since it will be at least another decade, and probably much more, before we see Umbriel close up again, it is unlikely to give up its secrets any time soon.

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Moons at Work

The ring-region Saturnian moons Prometheus and Pan are both caught "herding" their respective rings in this image. Through their gravitational disturbances of nearby ring particles, one moon maintains a gap in the outer A ring and the other helps keep a ring narrowly confined.

Prometheus (53 miles, or 86 kilometers across), together with Pandora (not seen in this image), maintains the narrow F ring seen at the bottom left in this image. Pan (17 miles, or 28 kilometers across) holds open the Encke gap in which it finds itself embedded in the center. The bright dot near the inner edge of the Encke gap is a background star.

This view looks toward the unilluminated side of the rings from about 29 degrees below the ringplane. The image was taken in visible violet light with the Cassini spacecraft narrow-angle camera on Sept. 18, 2012.

The view was acquired at a distance of approximately 1.4 million miles (2.3 million kilometers) from Pan and at a Sun-Pan-spacecraft, or phase, angle of 98 degrees. Image scale is 9 miles (14 kilometers) per pixel.

Credit: NASA/JPL-Caltech/Space Science Institute

The Cassini spacecraft looks toward Saturn's tiny moon Aegaeon within the G-ring arc.

[b][i]Credit: NASA/JPL-Caltech/Space Science Institute[/i][/b]

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The moonlet Aegaeon (formerly known as S/2008 S 1) can't be seen in this image, but it orbits in the bright arc of Saturn's faint G ring shown here. See Tiny Moonlet Within G Ring Arc to learn more.

Many background stars are visibly elongated by the motion of the spacecraft during the image's exposure. This view looks toward the northern, sunlit side of the rings from just above the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 4, 2011. The view was acquired at a distance of approximately 2.5 million kilometers (1.6 million miles) from Saturn. Image scale is 14 kilometers (9 miles) per pixel.

http://www.planetary.org/blog/article/00003072/ wrote:
Cassini finally catches Helene
The Planetary Society Blog
By Emily Lakdawalla Jun. 20, 2011

<<The Cassini team has had a wretched time trying to get pictures of Helene in the past, but their streak of bad luck is over. Helene is one of the four "co-orbital" moons in the Saturn system, which occupy metastable spots in the leading and trailing Lagrangian points on the orbits of Tethys and Dione. It's the biggest of the four, but that's not saying much; it's only about 36 by 32 by 30 kilometers across, so it's in the same general size range as Phobos. It's proven challenging to predict where it's going to be with enough accuracy to make sure Cassini can capture it in its camera field of view, with the result that nearly every imaging sequence that Cassini has been commanded to take of Helene has seen the moon wander out of the field of view at one time or another. Well, Cassini has finally achieved gorgeous global imaging of Helene with a spectacular flyby on Saturday, in which they absolutely nailed the spacecraft's pointing and got Helene to pose prettily for the camera from beginning to end of the encounter. And what a wacky, wacky world Cassini has revealed Helene to be!! We saw these gullies on the previous close flyby but this is a much better view. There are two things that are very strange about these gullies. One is to see them at all. Features like this, if seen on Earth or even Mars, would be assumed to have something to do with water, but there is no possibility of liquid water on Helene (though it is likely made mostly of rock-hard water ice). These gullies must form by a dry process in which material -- likely very powdery dusty stuff -- cascades toward local topographic lows.

[youtube]http://www.youtube.com/watch?v=g9nLyLXf ... r_embedded[/youtube]

Cassini's June 2011 Helene flyby (bounces 3 times)
As you watch the animation, try focusing on different areas.
Like the massive crater in the north that is partially illuminated
in the opening of the animation. Or the faceted shape of the moon,
which suddenly brings a huge sunlit face into view. Also try to see
if you can see the shadows move across Helene's face as it rotates;
most of the apparent motion is due to Cassini's motion,
but some is Helene rotating on its axis.
Credit: NASA / JPL / SSI / animation by Emily Lakdawalla

The other thing that is very strange is the strong difference in color between the higher-standing stuff and the smooth gully slide areas in between them. Others of Saturn's moons have some color variations across their surfaces, but really I don't know of one other than Iapetus where there are such sharp boundaries between one color of material and another. The color differences are most obvious on the right side of the image, where the Sun hits Helene directly and there aren't many cast shadows; color differences fade as you get toward the lower and lower light near the terminator at the left side of the image. Those color differences are what make this movie version of the flyby images appear to "beat" -- every time an image is shot through a short-wavelength ultraviolet filter, the inter-gully ridge areas darken substantially. I'm kind of proud of how this animation turned out -- feel free to share it!

Cassini got its best-ever view of Saturn's moon Helene on June 18, 2011, when it approached to within 7,000 kilometers. Helene is a co-orbital moon of Dione. The sunlit face is mostly the side of the moon that always faces Saturn, and is covered with strange gully-like features. The animation "bounces" back and forth to help the viewer see the 3D shape of Helene.

The surface appears to "beat" with contrast changes because Cassini was cycling through different filters to take the images. In short-wavelength filters, the areas between gullies are darker than the smooth gully floors, while there is less contrast between them in the longer-wavelength filters.

To generate this animation, I aligned the frames and rotated them 180 degrees to place north up. Then I used the Photoshop "dust and scratches" filter to remove most of the cosmic ray hits. This also removed a bit of detail from gully areas, unfortunately, but it saved me a lot of time and effort. I cleaned up the worst remaining cosmic ray hits using the clone tool. I adjusted the contrast to push black space to completely black and to bring out some more detail in shadowed areas.

There are a couple of dozen little tiny bowl-shaped impact craters scattered across the image, and there are eroded features that are almost certainly older, larger impact craters, but really there are not very many craters considering Helene's location in the shooting gallery of the Saturn system, so whatever process makes these gullies has also very likely been active recently and has wiped away past smaller craters. This inference becomes even more interesting when you look at the opposite face of Helene, the one that faces out from Saturn, which is heavily cratered as you might expect. Ian Regan put together a really nice comparison of Cassini's various views of Helene's two faces: Cassini's views of Helene through March 2010. Why are Helene's two sides so different? It's just one of many mysteries that Cassini's science team still has to solve.

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Cassini Captures Ice Queen Helene
NASA JPL-Caltech Cassini | 2011 Jun 20
CICLOPS: Helene Rev 149 Raw Preview

NASA’s Cassini spacecraft has successfully completed its second-closest encounter with Saturn’s icy moon Helene, beaming down raw images of the small moon. At closest approach, on June 18, Cassini flew within 4,330 miles (6,968 kilometers) of Helene’s surface. It was the second closest approach to Helene of the entire mission.

Cassini passed from Helene’s night side to the moon’s sunlit side. It also captured images of the Saturn-facing side of the moon in sunlight, a region that was only illuminated by sunlight reflected off Saturn the last time Cassini was close, in March 2010. This flyby will enable scientists to finish creating a global map of Helene, so they can better understand the history of impacts to the moon and gully-like features seen on previous flybys.

The closest Helene encounter of the mission took place on March 10, 2010, when Cassini flew within 1,131 miles (1,820 kilometers) of the moon.

Credit: NASA/JPL/SSI

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Ethereal Ring
Cassini Solstice Mission
NASA JPL-Caltech | 2011 May 02

The Cassini spacecraft looks toward the dark side of Saturn's largest moon and captures the halo-like ring produced by sunlight scattering through the periphery of Titan's atmosphere.

A detached, high-altitude global haze layer encircles Titan. See Titan's Halo to learn more. This view looks toward the trailing hemisphere of Titan (5,150 kilometers, or 3,200 miles across). North on Titan is up.

The image was taken with the Cassini spacecraft narrow-angle camera on Nov. 26, 2010 using a spectral filter sensitive to wavelengths of ultraviolet light centered at 338 nanometers. The view was obtained at a distance of approximately 1.9 million kilometers (1.2 million miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 154 degrees. Image scale is 12 kilometers (7 miles) per pixel.

Credit: NASA/JPL/SSI

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A crescent Enceladus, imaged from the night side, shows off its spectacular water ice plumes emanating from the south polar region of this moon of Saturn.

This image was captured at a phase, or Sun-Enceladus-spacecraft, angle of 157 degrees so that sunlight would reveal the backlit plumes. Terrain near the south pole is now dark as spring has come to the northern hemisphere of the moon. See Bursting at the Seams and New to Old on Enceladus for earlier, closer views.

Lit terrain seen here is on trailing hemisphere of Enceladus (504 kilometers, or 313 miles across). North is up.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 30, 2011. The view was obtained at a distance of approximately 228,000 kilometers (142,000 miles) from Enceladus. Image scale is 1 kilometer (0.6 miles) per pixel.

Credit: NASA/JPL/SSI

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Rhea and Dione seem like dark and light fraternal twins in this Cassini spacecraft image, with each of these two Saturnian moons displaying a large crater oriented similarly in the northern hemisphere.

Rhea, on the left, is closer to the Cassini spacecraft than Dione in this view. Saturn is out-of-frame, far to the right of this view.

Lit terrain seen here is on the anti-Saturn side of Rhea (1,528 kilometers, or 949 miles across) and the leading hemisphere of Dione (1,123 kilometers, or 698 miles across). North on the moons is up.

The image was taken in visible blue light with the Cassini spacecraft narrow-angle camera on Feb. 3, 2011. The view was acquired at a distance of approximately 1.2 million kilometers (746,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 75 degrees. The view was acquired at a distance of approximately 1.9 million kilometers (1.2 million miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 75 degrees. Image scale is 7 kilometers (4 miles) per pixel on Rhea and 11 kilometers (7 miles) per pixel on Dione.

Credit: NASA/JPL/SSI

Click to view full size image

Looking Over Enceladus (2011 Jan 24)

The Cassini spacecraft looks over cratered and tectonically deformed terrain on Saturn's moon Enceladus as the camera also catches a glimpse of the planet's rings in the background. The image was captured during the spacecraft's flyby of Enceladus on Nov. 30, 2010.

Geologically young terrain in the middle latitudes of the moon gives way to older, cratered terrain in the northern latitudes. See New to Old on Enceladus to learn more. This view is centered on terrain at 41 degrees north latitude, 202 degrees west longitude. North on Enceladus (504 kilometers, or 313 miles, across) is up and rotated 28 degrees to the right.

This view looks toward the northern, sunlit side of the rings from less than a degree above the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera. The view was acquired at a distance of approximately 46,000 kilometers (29,000 miles) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 14 degrees. Image scale is 276 meters (906 feet) per pixel.

Credit: NASA/JPL/SSI

Click to view full size image

Cassini: Hyperion: Somersaulting Moon (2011 Jan 10)

The Cassini spacecraft captures a view of the southern latitudes of Saturn's tumbling moon Hyperion.

To learn more about this spongy moon and how it tumbles in its orbit, see Encountering Hyperion, Cosmic Blasting Zone and Odd World. Lit terrain seen here is mostly in the southern hemisphere of Hyperion (270 kilometers, or 168 miles across). The south pole of the moon is near the bottom of the illuminated terrain seen here.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Nov. 28, 2010. The view was obtained at a distance of approximately 80,000 kilometers (50,000 miles) from Hyperion and at a Sun-Hyperion-spacecraft, or phase, angle of 98 degrees. Image scale is 476 meters (1,562 feet) per pixel.

Credit: NASA/JPL/SSI

There are six, count them, six moons in this photo. Plus the outer edge of Saturn's rings. Awesome.

[b][i]Credit: NASA/JPL/SSI/animation by Emily Lakdawalla [/i][/b]

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On October 6, 2010, Cassini managed to catch six different moons passing through its narrow-angle camera field of view at once. At the time, Cassini was on the southern (shadowed) side of the rings, so the uppermost part of the rings are closest to Cassini, and rings and moons orbiting Saturn appear to be going in a clockwise direction. With the Sun behind and to the left of the rings as seen from Cassini, the skinny multiple braid of the F ring is the brightest of all the visible rings; its sparse, dusty material scatters light forward to Cassini like dust motes in a sunbeam. The largest moon visible, Enceladus, is the farthest away from Cassini. Both Enceladus and Janus, the oval-shaped moon above it, have night sides lit by light reflected from Saturn. To the right of both Enceladus and Janus, between the bright F ring and the main rings, is Atlas. Immediately above Janus, orbiting along with a pair of ringlets within the Encke gap, is Pan. (Pan appears to be accompanied by a clump in one ringlet.) Immediately above Pan is Daphnis, making a bright spot within the Keeler gap at the outermost edge of the main rings. Above the F ring near the upper right corner of the image is Epimetheus. Unlike Janus and Enceladus, Epimetheus is located between Cassini and Saturn, so its night side is not lit up by reflected Saturnshine.

Click to view full size image

At least four distinct plumes of water ice spew out from the south polar region of Saturn's moon Enceladus in this dramatically illuminated image.

Light reflected off Saturn is illuminating the surface of the moon while the sun, almost directly behind Enceladus, is backlighting the plumes. See Bursting at the Seams to learn more about Enceladus and its plumes.

This view looks toward the Saturn-facing side of Enceladus (504 kilometers, or 313 miles across). North is up.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 25, 2009. The view was obtained at a distance of approximately 617,000 kilometers (383,000 miles) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 174 degrees. Image scale is 4 kilometers (2 miles) per pixel.

Credit: NASA/JPL/SSI

Click to view full size image

Although travelling at great speed, Cassini managed to capture this close view of Saturn's small moon Helene during a flyby on March 3, 2010.

Saturn's atmosphere makes up the background of this composition. See PIA12653 for another image taken during this closest flyby of Helene.

This view looks toward the anti-Saturn side of Helene (33 kilometers, 21 miles across). North on Helene is up and rotated 44 degrees to the right.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera. The view was obtained at a distance of approximately 19,000 kilometers (12,000 miles) from Helene and at a Sun-Helene-spacecraft, or phase, angle of 25 degrees. Image scale is 113 meters (370 feet) per pixel.

Credit: NASA/JPL/SSI

Click to view full size image

Cassini snapped this image during the spacecraft's closest flyby of Saturn's moon Helene on March 3, 2010.

See PIA09015 for the previous closest view of Helene (33 kilometers, 21 miles across). The small moon leads Dione by 60 degrees in the moons' shared orbit. Helene is a "Trojan" moon of Dione, named for the Trojan asteroids that orbit 60 degrees ahead of and behind Jupiter as it circles the Sun.

Lit terrain seen here is on the anti-Saturn side of Helene. The south pole of the moon is in the lower right of the image.

The image was taken in visible light with the Cassini spacecraft wide-angle camera. The view was obtained at a distance of approximately 1,900 kilometers (1,200 miles) from Helene and at a Sun-Helene-spacecraft, or phase, angle of 90 degrees. Scale in the original image was 235 meters (770 feet) per pixel. The image has been magnified by a factor of two and contrast-enhanced to aid visibility.

Credit: NASA/JPL/SSI

Click to view full size image

Cresent Moon

A last quarter crescent moon above Earth's horizon is featured in this image photographed by the Expedition 24 crew on the International Space Station.

Image Credit: NASA

bystander wrote:

mexhunter wrote: http://www.nasa.gov/multimedia/imagegal ... _1761.html

See previous page: http://asterisk.apod.com/vie ... 36#p132236

mexhunter wrote: http://www.nasa.gov/multimedia/imagegal ... _1761.html

owlice wrote:
beyond, you're clearly too young to know the reference for hummina hummina hummina.
Bet neufer gets it, though; he's even older than I am.

http://www.freemasonry.bcy.ca/fiction/fraternities/raccoons.html wrote:
International Order of Friendly Sons of the Raccoons

[img3="Arthur William Matthew "Art" Carney (1918/11/04 - 2003/11/09) and
Herbert John "Jackie" Gleason (1916/02/26 - 1987/06/24)"]http://www.freemasonry.bcy.ca/fiction/f ... ccoons.jpg[/img3]

Bus driver Ralph Kramden (Jackie Gleason) and sewer worker Ed Norton (Art Carney) were members of the Raccoon Lodge in Brooklyn, New York. The fraternity was called the International Order of Friendly Sons of the Raccoons, the International Order of Loyal Raccoons, or at times, the Royal Order of Raccoons. Founded by Toots Mondello and Herman Hildebrand in 1907,
their motto was "E Pluribus Raccoon".

Ralph and Ed belonged to Bensonhurst chapter which had a membership of 300. Their uniform, costing $35, was a double-breasted military jacket with oversized epaulets on each shoulder, white shirt, dark tie and a hat with a raccoon tail. Morris Fink, a sewer worker with Ed Norton, was the Grand High Exhalted Mystic Ruler. He wore three tails on his coonskin hat. George Williams was the president of the Bensonhurst Raccoons. Monthly dues were $2.

Official club greeting (Bylaws, sec. 2)

The handshake involved touching elbows (first right then left), followed by a "Woooooo" sounding cry as they wiggled the raccoon tail on their lodge hat. They ended by
chorusing: "Brothers under the pelt."

Club songs

• Alma Mater
  
  From the hallowed streets of Greenpernt,
  To the shores of Sheepshead Bay,
  From the Verrazano Narrows,
  To Canarsie across the way...
  We have come together, one and all,
  In fellowship to commune,
  And to glorify the Grand Exalted
  Brotherhood of Raccoons. [Howl]
  
  Marching song
  
  In the West and in the East
  There’s a mighty little beast
  For courage there is no other.
  When the chips are all at stake
  We are proud to call him brother.
  So with our noble tails entwined
  And a spirit strong of mind
  We'll have hearts that cannot melt.
  In the forest, in the trees
  On the land or seven seas
  We're brothers under the pelt.
  Raccoons, the noble Raccoons

Membership requirements (Bylaws, sec. 2)
- US citizen for the last six months
- have a public school diploma
- pay a $1.50 initiation fee.

Raccoon of the Year privileges
- Opening the first clam at the annual clambake
- Steering the boat on the annual ride up the Hudson River to Raccoon point.
- Free burial with spouse at Raccoon National Cemetery in Bismark, North Dakota.
- Opportunity to run for Grand High Exhalted Mystic Ruler.
- Throwing the first bag of water out of the hotel window at the Raccoon convention.

Lodge events
- Annual national conventions in Chicago and Minneapolis.
- Annual ride up the Hudson River to Raccoon point.
- Annual clambake.
- Annual fishing trip (wives not allowed)
- National Mambo dance championship.
- Annual Costume Party.
- Raccoon Lodge bowling team, the Hurricanes.
There was a $15 fee for each event.

Drinking toast: Fingers to fingers, thumbs to thumbs, watch out below, here she comes.

bystander wrote:

beyond wrote:But your Hummina, hummina, hummina, leaves me in the dark even when i find out Hummina Gleason is a champion Mastiff. So is hummina,hummina,hummina a referrence to everything going to the dogs

But what about the Hummina,hummina,hummina

The Honeymooners' Ralph Kramden (Jackie Gleason) used to say "hummina hummina hummina" when stumped and at a loss for words, especially when caught in one of his schemes by owlice, his wife.

The name Hummina Gleason is a tribute to Jackie Gleason.

beyond wrote: Owlice, you forgot to ask who went tobogganing across the moonscape.

beyond wrote:But your Hummina, hummina, hummina, leaves me in the dark even when i find out Hummina Gleason is a champion Mastiff.
So is hummina,hummina,hummina a referrence to everything going to the dogs

But what about the Hummina,hummina,hummina