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Spectacular New Views of Saturn's Polar Vortex
sighted writes "Today the robotic spacecraft Cassini returned some jaw-dropping images of the odd hexagon in the planet's north polar region. The hexagon has been seen before, but the change of season has more fully revealed the feature in visible light. Cassini also zoomed in on the churning vortex at the north pole itself. The south pole features a similar maelstrom."
What an incredible image, I'd love to see it as a stereoscopic image to really capture the depth of the clouds. Shouldn't be too hard - at orbital speeds two images taken a few seconds apart should capture incredible depth while the storm is unlikely to have changed significantly.
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Yeah, it's been wild here too.
...omphaloskepsis often...
See research done by Ana Claudia Barbosa Aguiar and Peter Read at Oxford in 2010. They were able to recreate this phenomenon in the lab. It has to do with interaction the rotating atmosphere of Saturn with a jet stream near the pole. By adjusting the speed of revolution of the jet stream they were able to create pretty much any desired shape.
....when human beings, if ever, will get to see such things directly with their own eyes. How far away are such times ?
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When I looked at the pictures I saw fractals.
Very very complex fractals.
Hopefully one day some brainy guy can come out with a 3D fractal program that can simulate this absolute wonder.
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Gorgeous! Now... someone said something about a planet or some such? All I could see was the redhead.
A hexagon!? Clearly that has to be the work of intelligent beings. There must be some sort of alien presence on Saturn. The clouds probably hide the base they have used to observe for centuries. I hope the History channel's Ancient Aliens puts some of their first class investigative journalists and deductive scientists on this right away.
This is an amazing image, but why isn't it in color?
Because color is for pussies. Astronomers use either plain gray-scale imaging, or, perhaps even more often, a set of filters to extract bands or wavelengths of interest. The problem is, all colors assigned to a filtered gray-scale image or a combination thereof are usually false colors, since they generally don't correspond to the sensitivity bands of the retinal cones in your eye. The false colors are often useful, but you'd complain the same ("the colors look weird!"). Fairly rarely do astronomers take a veritable RGB combination - they usually do it when a major press release is on horizon, to have some nice pics for the lay public. ;-)
Ezekiel 23:20
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Because they haven't coloured it in yet, seriously the images are composed of specific wavelengths, the 'negative" is a grey scale of the intensity, the different wavelength negatives are stacked to form the raw B&W image in the link. Different colour sets are used to highlight different features, bonus points are awarded if it's also a pretty picture.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
It's because using telescopes on such a vast distances corrupts the colour. Remember, that the colours we can see, and appreciate are bound in to a narrow band of frequencies, and taking pictures on a single frequency make better pictures. Of course, you could do 3 distinct images, in the red, green, blue frequency bands, but by that time you make three photos, Cassini changes its position considerably, hence the photos will not cover the same angle. It's fairly big thing to get a single frequency band photograph with proper exposition time. Earth based amateur astronomers do the same thing: take photos of a celestial object with different different filters, and later combine the photos. However, they have the benefit not to observe much large angle change as the Cassini orbiting Saturn.
Welcome to the world of scientific research. It's a scientific article, which are almost always behind a paywall. ScienceDirect (operated by publisher Elsevier) is one of the largest scientific journal conglomerates. Universities pay 10's of thousands of dollars every year, if not more, to give their researchers access to these journals. So the authors make no money on it, but Elsevier makes loads on these articles.
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There is a large Hex nut holding the poles together - and you call yourselves scientists?
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...to use different parts of the spectrum and, like you say, maybe some parts that are not normally visible to the human eye.
It's not just that you can cover different parts of the spectrum than you usually see with your eyes. It's simply the fact that even if you use filters that do cover the RGB parts of the spectrum, but do it in a different way than the retinal cones, you'll end up - after reconstructing the image either in print or on an RGB monitor - with a picture that has distorted colors. Two different shades of green (as you see them with your own eyes) can end up looking identical in the reproduction, or the other way round - the different spectral sensitivity of the camera will show a "single" shade of green as being actually varying across the picture. That's interesting from the POV of an artist, but not much else. For astronomic science, RGB is mostly worthless.
Also, maybe this B&W camera (or whatever type of filtering it's using) is more reliable to send in a space probe that far out into space...
The problem is that once you build a single-exposure color camera (with a fixed filter integrated in front of each and every pixel), you end up with being able to do only RGB images. You'd need a second camera for everything else. You can use additional filters - photographers do this all the time - but for the purpose of scientific measurements, you're screwed. (Feel free to contemplate the difficulty of assessing the intensity of a single spectral wavelength along two spatial coordinates (e.g., an image) using an RGB camera and a monochromatic filter.)
or just to relay the information back to Earth to be used. I'm not saying it's not possible to send color data back or that it's easier/harder than this.
There's no practical difference here.
Ezekiel 23:20
I strung together 7 raw images from cassini's website into a simple animtation: https://docs.google.com/file/d/0B5BO-IJLRe8EdjFiTDZJS21QNXM/edit
Only the Voyager 2 probe flew past Uranus, and I don't think it took pictures of the poles. The Galileo probe orbited Jupiter for many years, but I don't think its orbit was high enough (in terms of latitude) to get clear views of the poles. For example, this site includes a polar view of Jupiter: http://thebigfoto.com/jupiter-from-space but it's a composite of many pictures, and the fuzziness of the polar region suggests that it's a re-projection of oblique views taken from a lower-latitude images.
And this is easily my favourite vortex.
Only the Voyager 2 probe flew past Uranus, and I don't think it took pictures of the poles
Why do you say that? Given Uranus' axial tilt of 90+ degrees and the fact that Voyager 2 flew around it in a plane roughly parallel to the ecliptic, I'd say it would be a work for art for Voyager 2 to take a series of pictures of Uranus without capturing at least one of the poles at least once (that is, with an angle of incidence, say, less than 40 degrees). There was a summer solstice on Uranus' south pole in 1986, which means that this picture should have the south pole somewhere near the center, or perhaps in the top right quadrant of the planet's disk.
A much greater problem is that there is not much to see there. Uranus' appearance is very bland, compared to the other gas giants in the Solar system.
Ezekiel 23:20
(Slaps forehead)