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NASA Discovers Giant Ring Around Saturn
caffiend666 writes with news that scientists using the Spitzer Space Telescope have discovered a very large, previously unknown ring around the planet Saturn. According to NASA, if the ring were visible to the naked eye from Earth, it would cover a patch of sky roughly twice the angular diameter of the Moon.
"The new belt lies at the far reaches of the Saturnian system, with an orbit tilted 27 degrees from the main ring plane. The bulk of its material starts about six million kilometers away from the planet and extends outward roughly another 12 million kilometers. One of Saturn's farthest moons, Phoebe, circles within the newfound ring, and is likely the source of its material. Saturn's newest halo is thick, too — its vertical height is about 20 times the diameter of the planet. It would take about one billion Earths stacked together to fill the ring. ... The ring itself is tenuous, made up of a thin array of ice and dust particles. Spitzer's infrared eyes were able to spot the glow of the band's cool dust. The telescope, launched in 2003, is currently 107 million kilometers from Earth in orbit around the sun."
...it wasn't a giant ring around Uranus.
Yeah, yeah, just thought I'd get that out of the way early.
Which was... "DUH!". Galileo discovered the "huge rings around Saturn". But reading deeper this is a fascinating find, that the invisible portion of the rings are way bigger than the spectacularly visible ones.
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I'm not sure I understand why something so large was missed by Voyager. I understand the difficulty of viewing something like this from Earth but those probes were right there.
A better headline would've been, "NASA Discovers Previously Unknown Ring Around Saturn"
Couldn't help myself, from TFA (emphasis added):
Before the discovery Saturn was known to have seven main rings named A through E and several faint unnamed rings.
What kind of a messed up numeral system do they use in NASA?
Joking aside, the ring divisions are labelled (from the closest to furthest) : D, C, B, A then F, G and finally E as the outermost ring.
Wonder what they will name this one, anyone good with sequence puzzles?
Cool Dust? Wow, I could have used some of that in high school. This is undoubtedly part of some astronomy group's secret project to get back at the jocks.
NASA Discovers Giant Ring Around Saturn
They figured it out just now?
This proves it. The moon landings were fake.
I don't know if you could consider this is part of the ring system around Saturn due to the fact that is start around 3.7 millions miles away from the planet and stretched out to its furthest at 7.4 millions miles; I'm not an astronomer by any means but I would consider this and asteroid belt of some sort; Saturn gravitation pulled cannot be that strong holding materials that far away.
Is this ring the source of the dark material on Iapetus?
(Looking at the images of Iapetus, my instant reaction was that it looked exactly like objects that I've spray-painted at an oblique angle -- and by analogy the dark surface MUST be accreted material from a dust cloud.)
Put my fist through my alarm clock with its ding-dong death inside my ear. - The Blackjacks.
Now that the funny is out of the way...
I would think that this kind of discovery could close the gap for some of the physics problems we are trying to solve. Could the headline have read 'Missing matter discovered around Saturn'? Supposedly we are missing 75% of the matter in the universe or some percentage.
Ice in space? I wonder what we could do with that. Maybe Mars isn't so boring after all.
That's -193'C or 80 K if you're an actual scientist.
...has an inner radius of 5.9 million kilometers and extends to 17 million km.
That's "so huge it would take 1.03×10^29 Volkswagens to fill it"
JPL is a collection of buildings in California and does not speak. Perhaps the Oracle of JPL made this prophecy?
Unless the McDonalds in Charlottesville have changed recently, 10^29 Volkswagens would be a 'Large'. If you want supersized rings it's going to be an extra 49 cents.
They put a ring around the ring so you can rosie around the rosie.
If these rings are so see through and spread out how can you measure where the boundaries of it are?
I think they did!
Anything you "discover" is previously unknown, by definition. Otherwise, the headline would have said "rediscover".
You pedants, when will you learn?
What's hard to understand about that?
It even said: It's the apparent size.
In other words, the angular size is how big something looks if you disregard how far away it is.
For instance, here is a picture of a bird silhouetted against the moon. The bird is close to the viewer (appearing large) and the moon very far away (appearing small). Although we know it's huge, the moon looks like it's nearly the same size as the bird. Their visual diameters are nearly the same.
Here's another picture of a bird silhouetted against the moon. In this one, the bird is quite far away (though nowhere near as far away as the moon), and looks small in comparison. The moon is about the same size (visual diameter) as it was in the last picture, but the visual diameter of the bird is much smaller.
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Is anyone looking for these invisible rings in other places?
Yes. Fools that they are.
Brain surgery - it's not rocket science!
Saturn has four main groups of rings and three fainter, narrower ring groups. These groups are separated by gaps called divisions. Close up views of Saturn's rings by the Voyager spacecrafts, which flew by them in 1980 and 1981, showed that these seven ring groups are made up of thousands of smaller rings. The exact number is not known.
The main rings are extremely thin. They stretch 70,000 kilometres from their inner to outer edge, but are only about 100 metres thick. They are made of loose ice particles in all sorts of sizes.
"They go from the size of houses down to the finest ice particles, like the snow you might ski on in Utah" says Carolyn Porco, head of Cassini's imaging team and an expert on the rings.
Voyager showed that thousands of gaps break the main rings up into ringlets that are often only a few kilometres wide. In the pictures from Cassini, it is clear that some ringlets are narrower still, maybe only half a kilometre or less.
Those pictures also show that they have very sharp edges, even though the ice particles should be bouncing off each other and blurring the edges of the rings. "It's very mysterious - they must be held sharp by some mechanism," says Porco. "In some cases it is done by moons, but with many of the edges we don't know the mechanism."
Maybe some of the questions raised by Voyager and Cassini can be answered by these new findings.
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Impacts. Stuff gets kicked up from Phoebe and accreted by Iapetus:
I can sell you an invisible ring that keeps invisible tigers away! I've been wearing mine for years and in all that time didn't see a single invisible tiger!
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Here is the original article on Spitzer's site: http://spitzer.caltech.edu/news/964-ssc2009-18-NASA-s-Spitzer-Spots-Clump-of-Swirling-Planetary-Material
The other post had some good tips. Note that strictly speaking you don't need a tracking telescope. You can take a bunch of 10s exposures with a half-decent camera and then overlay them to get a better image. There is software out there that will do this semi-automatically (google for stacking), or you can just use Photoshop.
Don't expect to get something like what you'd see out of the Hubble. In my light-polluted area (suburban), with a 50mm f/1.8 lens, I was able to get a small hazy disc with a central bulge. I suspect my focus was a bit off (very hard to focus a camera on a dark sky - use live view if you have it). Even so, it was fairly clear that the object was a galaxy.
To help locate it in a photo be sure to consult a star chart that includes low-magnitude stars. The stars that you can actually see will be fairly large and prominant in your photo, but they'll be far apart. You'll have lots of small stars that you can't see with your eyes, but decent charts will have them.
Astronomy software will calculate the altitude (angle above horizon) and azimuth (compass heading) for any location date/time. If you don't have access to software, this website will work. You need to enter your own lat/long, and the time in UTC. For the RA/Dec use (from wikipedia):
Right ascension 00h 42m 44.3s
Declination +41 16 9
Right now it appears that in the US that M31 is below the horizon for most of the night. You might have to wait six months to get a good shot.
Disclaimer - while I have an interest in this stuff I wouldn't call myself even an amateur astronomer. Also - if Andromeda is invisible I suspect there is a chance that Orion is above the horizon and it also has a decent-sized nebula (but I'm not sure if you could get that without a telescope).
NASA posted a great composite shot a few years ago showing the full moon and the Andromeda galaxy at the same angular scale.
Astronomy Picture of the Day: Moon over Andromeda.
Well, there's also this ... if I'm reading the description correctly, it's the Spitzer infrared picture, with an enhanced inset plus an inset photo of Saturn taken by the Hubble.
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
We are making one.