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NASA's Cassini Captures Photos of Saturn's Rings In Unprecedented Detail (voanews.com)

Posted by BeauHD on from the mother-nature dept.

NASA's Cassini probe has captured news images of Saturn's rings in unprecedented detail. The images were captured by the probe in its penultimate mission phase of its mission that includes "20 orbits that dive past the outer edge of the main ring system" before the spacecraft plunges into the planet itself. Interestingly, the rings include what NASA calls "moonlets" embedded in them. VOA News reports: The images are the closest ever taken of Saturn's rings and, according to NASA âoeresolve details as small as 550 meters, which is on the scale of Earth's tallest buildings.â The"ring-grazing" orbits began last November and will continue until the end of April, and in addition to spotting the moonlets, they have given greater clarity to other structures within the rings such as the so-called propeller-like formations. NASA added that Cassini has also provided the "closest-ever" glimpses of two small moons, Daphnis and Pandora. The report via NASA Jet Propulsion Laboratory (JPL) adds: "Some of the structures seen in recent Cassini images have not been visible at this level of detail since the spacecraft arrived at Saturn in mid-2004. At that time, fine details like straw and propellers -- which are caused by clumping ring particles and small, embedded moonlets, respectively -- had never been seen before. (Although propellers were present in Cassini's arrival images, they were actually discovered in later analysis, the following year.) Cassini came a bit closer to the rings during its arrival at Saturn, but the quality of those arrival images (examples: 1, 2, 3) was not as high as in the new views. Those precious few observations only looked out on the backlit side of the rings, and the team chose short exposure times to minimize smearing due to Cassini's fast motion as it vaulted over the ring plane. This resulted in images that were scientifically stunning, but somewhat dark and noisy.

43 comments

  1. Uranus by cobester · · Score: 0, Troll

    I would prefer to see the rings around uranus.

    1. Re:Uranus by Tablizer · · Score: 1

      One of the few people who deserve a goat-se link

      --
      Table-ized A.I.
  2. Vinyl by Anonymous Coward · · Score: 4, Funny

    It kinda looks like a vinyl record. Has anyone tried playing it yet?

    1. Re:Vinyl by Sporkinum · · Score: 1

      I had the same thought. Probably sounds like Lou Reed's Metal Machine Music.

      --
      "He's lost in a 'floyd hole"
    2. Re:Vinyl by Tablizer · · Score: 2

      It kinda looks like a vinyl record. Has anyone tried playing it yet?

      I ran it through a digital player, and it said, "All your bases are belong to a blind trust managed by my offspring."

      --
      Table-ized A.I.
    3. Re:Vinyl by Gravis+Zero · · Score: 1

      It kinda looks like a vinyl record. Has anyone tried playing it yet?

      It was an interesting idea so I actually used 287 images taken by NASA's probe to compose a virtual "vinyl imprint". I then used an optical recognition program to decode the audio and the result was great.

      --
      Anons need not reply. Questions end with a question mark.
    4. Re:Vinyl by Plumpaquatsch · · Score: 1

      It kinda looks like a vinyl record. Has anyone tried playing it yet?

      It plays: "Because of the movie, the Monolith can now be found in orbit around Jupiter."

      --
      Of course news about a fake are Fake News.
  3. Hmm by joh · · Score: 4, Interesting

    I would love to see a probe going into an orbit that is synchronized to the rings. And then slowly dives into the rings, between all the small and bigger particles that make up the ring. Must be like a somewhat dense cloud of debris moving along in parallel without much motion between them.

    1. Re:Hmm by wisebabo · · Score: 2

      I once, a long time ago in a place far far away, went to the JPL monthly lecture in Pasadena California. This one was about the Cassini probe then completing its first few months around Saturn.

      After the lecture, under the imposing model of one of the Voyager spacecraft, I met with the Project Scientist (I'm not sure if she is the same one as the current one) and asked her if they could do a "risky" maneuver at the end of Cassini's lifetime. Have Cassini go to the rings (in a synchronized fashion as you say) but stay "just" above them using a continual very low thrust from its main engine(s) or thrusters.

      I had seen the pictures taken edge on of the rings and seen how "razor" thin they were (at least on a cosmic scale). It appeared to (my very unprofessional, untrained eye) that there was no debris or particles immediately above or below the rings. There seems to be some mechanism which causes particles to stay exactly within the rings (collisions and redistribution of momentum?). So, maybe Cassini could just apply a very small amount of thrust, perpendicular to the ring plane, to counteract its orbital trajectory that would normally take it up and down through the ring. It could then hover a few (tens? hundreds?) kilometers above the rings and could get unbelievable closeups of them without getting ground to pieces.

      I think she just laughed and probably knew of a dozen reasons why this wouldn't work (the thrust would be too low, the propellant use too high, there was still probably way too much debris around, they wouldn't be able to navigate that accurately, etc.). Still your comment made me think about this, and that someday maybe with a probe with an (low) thrust long duration ion drive, it would be able to float just above the rings (as close as would be safe), synchronized with them, and be able to take spectacular long duration exposures of the tumbling pebbles, boulders, mountains that make up this spectacle.

    2. Re:Hmm by joh · · Score: 2

      Well, I think there is still some "action" going on in the rings. Even if everything in there would be totally synchronized with no relative motion (especially then) you would get mass clumps of particles slowly being drawn toward each other by their own mass/gravity. Basically the same thing that led to planets forming from rings of particles in the early solar system. But then this would be extremely interesting to research, because it would be the nearest thing to look at for such processes.

      It would be wise to use a somewhat rugged probe with nuclear power (no fragile solar panels) with some shielding, retractable instruments and an ion drive... Anyway, there are lots of cool things to explore left in the solar system and the closer you look the more interesting things you find!

    3. Re:Hmm by Anonymous Coward · · Score: 0

      There seems to be some mechanism which causes particles to stay exactly within the rings (collisions and redistribution of momentum?)

      The gravity of the material in the ring gives a larger force in the frame of the ring than the gradient in Saturn's gravity. So stuff pulled out of the plane of the ring tends to pull back and oscillate on a timescale much shorter than an orbit. But yeah, you need collisions and momentum transfer to dampen that oscillation, but the ring is thought to be very clumpy with many low speed collisions.

      But the gravity from the rings, despite being weak, would still add to the station keeping effort a probe would need to stay out of the ring.

      For close up images, I would think you could get reasonably high chances by going through a gap in vicinity of a moon. There is still stuff there, but the density is much lower around where the moon as cleaned things up. Plus the moon could be used to help deflect you back out of that orbit so you don't take that risk multiple times or need a lot of fuel to get out of that orbit. Some of these gaps with moons are only a couple 10s of km in size.

    4. Re:Hmm by Solandri · · Score: 1

      Pioneer 11 was the first probe to visit Saturn. One of its trajectories considered for the mission (and eventually rejected) was to pass right through the Cassini Division. Once Pioneer got there, we found out the Cassini Division wasn't quite as empty as it appears from Earth.

  4. I'm sorry, Fry by Anonymous Coward · · Score: 0

    Astronomers renamed Uranus in 2620 to end that stupid joke once and for all

    1. Re:I'm sorry, Fry by Anonymous Coward · · Score: 0

      I don't give a fuck, I still call Pluto a planet.

    2. Re:I'm sorry, Fry by donaggie03 · · Score: 1

      Oh. What's it called now?

      --
      Three days from now?? Thats tomorrow!! ~Peter Griffin
    3. Re: I'm sorry, Fry by Anonymous Coward · · Score: 0

      We'll have to survive another 603 years to find out. Isn't this exciting? I wonder how many dimensions strings will vibrate in by then...

    4. Re:I'm sorry, Fry by Anonymous Coward · · Score: 0

      Oh. What's it called now?

      Jeez, it took over four hours to get that posted? I tee up a straight line like that, and more than four fucking hours?

      Slashdot has failed.

    5. Re:I'm sorry, Fry by Anonymous Coward · · Score: 0

      Urectum.

    6. Re:I'm sorry, Fry by Anonymous Coward · · Score: 0

      Probably the posting limits on anonymous cowards.

  5. Sigh of relief...... by Warrernoia · · Score: 0

    No pertubations in the rings from Chtaptisk Fithp's Message-Bearer.

  6. Slight pet peeve of mine-- by wierd_w · · Score: 3, Informative

    NASA seems to really really love using monochrome imaging systems.

    Look, I GET that this is in the outer solar system, and that the sun's light is very pitifully weak out there. I GET that. I understand that they want to gather as much light as is possible in the images.

    However, monochrome CCDs dont care what frequency the photons are. As long as they can pass through the forward optics and focus, they will add to the luminosity of the resulting image. That means that dust could be very reflective of IR, or UV light, and it would have the same whiteness. Sure, you could subtract some of that out using special optics for IR and UV, and create some horrid false-color image that does not reflect reality at all, other than artificially showing where there is UV or IR reflectivity, but visible light absorbtion/emission spectra are also very useful for scientific enquiry into such objects.

    Why does NASA not at least TRY to get true color images with extended exposure times?

    It's been a pet peeve of my for years, and I cant be the only one. I KNOW they can do it, because Voyager took lots of true color images back in the 70s. CCD tech has greatly improved since then.

    1. Re:Slight pet peeve of mine-- by dargaud · · Score: 4, Informative

      Color CCDs have several disadvantages over monochrome ones for science applications: lower sensitivity, bleeding, aliasing, complexity... So normally for color pictures in space, they simply use filters of various frequencies: R, G, B for color pics, but also IR, UV and various peak frequencies of interesting chemicals (very important for science). This way it's not just a camera, but a full on science measurement. Every space camera is used like that. But why wasn't it used here ? Simply because the relative motion was too fast: they already had to use a short exposure time in order not to get a blurry shot, but changing filters take time and the pics wouldn't match in later post-processing. This method only works for subjects that don't move (or if you don't move yourself).

      --
      Non-Linux Penguins ?
    2. Re:Slight pet peeve of mine-- by Anonymous Coward · · Score: 0

      I agree with you completely. I worked on Voyager Uranus and Neptune, and Galileo. I wondered the same thing. Composing color images from separate exposures is a total hack.

    3. Re:Slight pet peeve of mine-- by wierd_w · · Score: 1

      A method similar to what is done for digital HDR recording would fix this problem, but would admittedly add tremendously to the vehicle weight.

      EG, you have a single forward optic, but introduce several beam splitters, which then go to individual monochrome CCDs behind the various filters. (use a clear saphire prism beam splitter to get nIR and UV on the same source optic) You then assign each CCD a channel, and develop the image accordingly.

    4. Re:Slight pet peeve of mine-- by ColdWetDog · · Score: 1

      Yes and adding tremendously to the vehicle weight (and complexity and cost) is exactly what drives rocket scientists to vote Democratic. These probes are all about compromise. I'm sure this argument is played out in a bunch of archived memos somewhere.

      The fact that this thing has been operating since 1997 and pushing the boundaries of planetary science says they made most of the right decisions.

      --
      Faster! Faster! Faster would be better!
    5. Re:Slight pet peeve of mine-- by jfdavis668 · · Score: 2

      Color cameras are just crippled cameras. Each pixel in the image is made from 4 pixels in the camera. One red, one blue and 2 green. The camera then balances the output to make the output pixel. With a monochrome camera, each pixel provides separate output. That way data is collected 4 times faster. When astronomers, both professional and amateur, create those wonderful color pictures of deep sky objects, they do it with filters and a monochrome camera. They will take many pictures to collect hours of black and white images to get all the detail. Then they may take separate red, green, and blue images to add the color. Or, they may use filters that take in the light of certain elements like hydrogen, oxygen and sulfur. They then use software to combine all that information into the final product.

    6. Re:Slight pet peeve of mine-- by Anonymous Coward · · Score: 0

      Taking multiple photos at the same time of different color bands would add very little to the science value, as the vast majority of what is being studied doesn't care if the photos are a couple seconds apart or doesn't care about the color that much. But it would potentially take away from the science, because you're now talking about tripling the weight, but actually reducing the number of colors it can see as many such cameras will have six or more filters available. About the only benefit would be throughput if you were expecting to take a lot of images that needed full color (not necessary for a lot of missions), as it just cuts your total exposure time by a third (assuming you have enough light and your dichroic splitters are efficient enough).

      Most experiments would benefit more from having a camera and an imaging spectrometer, or use the weight budget on different cameras for vastly different bands, like a visible, IR and UV camera where a single camera with filters would do poorly. Then you wouldn't want to use splitters probably, as depending on your mission, a jack of all trade optics system might suck compared to separate optics specifically built for the widely separated bands.

    7. Re:Slight pet peeve of mine-- by Anonymous Coward · · Score: 1

      I KNOW they can do it, because Voyager took lots of true color images back in the 70s. CCD tech has greatly improved since then.

      No, you remember very wrong. Voyager didn't use CCD visible light cameras, but vidicon tubes like old TV cameras. Also, both the Narrow Angle Camera and Wide Angle Camera used a filter wheel with 8 different filters.

    8. Re:Slight pet peeve of mine-- by Anonymous Coward · · Score: 0

      "Taking multiple photos at the same time of different color bands would add very little to the science value"

      True..
      But do you know what DOES add to science value?
      FUNDING

      If they want the public to FUND science, they need to provide science that the public values.
      Showing black and white photos, that the majority will look at and say, 'HEY, we saw black and white photos of this space stuff 30 years ago, what a wast of money!' does nothing to insure additional funding.

      Showing some wonderful never before seen color picture might.

      It's simple to me.
      If you can get a color camera system built and added to the probe that takes a few extra pounds and hundreds of thousands of extra in fuel and testing do it. DO IT.
      It will probably get you tens of millions in additional funding.

    9. Re:Slight pet peeve of mine-- by Bryan+Ischo · · Score: 1

      Claiming that color images will incite the public to demand more funding for NASA is a stretch about as far as from here to Saturn's rings.

    10. Re: Slight pet peeve of mine-- by Anonymous Coward · · Score: 0

      Except NASA does release a lot of color photos with the systems already in use. You think a difference in the type of filter used to make those images will make millions of difference in funding? On projects where a couple hundred pounds is a significant fraction of the probe and the project cost more than a hundred million dollars, you would have a net loss even if we optimistically took your proposal at face value.

    11. Re:Slight pet peeve of mine-- by sid1950 · · Score: 0

      The tech on Cassini is at least 20 years old! Have you any idea how much effort goes into keeping the spacecraft weight down? And another thing. How come nobody here knows who the scientist in charge of the Cassini Imaging Team is? Caroline Porco was one of Sagan's grad students working on Voyager. She worked out how to take the famous "Family Portrait" montage with the Pale Blue dot photo. Do you think it might be possible that she knows what she what she was doing with this project? When you say "CCD tech has improved since then", do you realise it was launched in 1997?

      --
      Best wishes,

      Sid

    12. Re: Slight pet peeve of mine-- by Anonymous Coward · · Score: 0

      He is completely wrong about Voyager, so I do the know why you expect him to know anything else.

  7. I think they meant by Anonymous Coward · · Score: 0

    Unpresidented

  8. Why does NASA not at least TRY... by turkeydance · · Score: 4, Funny

    their revised unlimited plan has data caps.

  9. Re:Anarchy by jfdavis668 · · Score: 1

    But he's causing anarchy! You should be in high heaven.

  10. Voice of america by Anonymous Coward · · Score: 0

    Don't link to propaganda sites when there are legit sources like jpl

    1. Re:Voice of america by Tablizer · · Score: 1

      "Popularized" articles on space do illustrate many of the problems with "news" in general: it's sloppy and sensationalized. Often bias itself is not directly the problem. The publisher wants to maximize readership using exaggeration and impressions of extreme acts or motivations to get reader attention; and spend diddly squat on research, experts, vetting, citations, footnotes, etc. to save a buck.

      "While hurtling toward its gruesome death-by-crushing from the giant menacing ringed planet, the doomed Cassini probe captures the final and most detailed captivating shots of the rings ever seen by any human being, thanks to NASA's Ultimate Bucket List!"

      --
      Table-ized A.I.
  11. It's a space probe, not a bumper car by Tablizer · · Score: 1

    nuf sed

    --
    Table-ized A.I.
  12. Not before they were heavily altered and photoshop by Anonymous Coward · · Score: 0

    Never ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever ever

    EVER

    Believe a thing NASA says is true.

    NASA censors Everything, which your tax dollars fully pay for. You are not allowed to know the true nature of your reality. You sure are unintelligent anuses and have nothing better to do but argue about trump and hillary