Saturn’s moon Iapetus has fascinated astronomers since Cassini discovered in 1671 that it seemed to appear and disappear in orbit around its parent planet. This little walnut-shaped beaten and battered moon’s later claim to fame would be that it appeared to be bright on one side and dark on the other, which is why he could only see it on the western side of the planet and then it would seemingly vanish.
How it got that way would cause a lot of speculation down through the centuries.
In February of 2009 a trio of astronomers at The University of Virginia in Charlottesville lobbied for the use of NASA’s infrared Spitzer Space Telescope to investigate the long-standing theory that Iapetus was being “painted” with soot from another of Saturn’s moons; namely Phoebe. What team leader Anne Verbiscer and her colleagues Douglas Hamilton and Michael Skrutskie discovered would write a new chapter in astronomic history.
They found that over a span of millions of years, meteorite impacts on Phoebe had indeed kicked up enough dust to paint Iapetus, which orbits Saturn like our own moon with one hemisphere always facing the planet. Since the two possibly captured moons orbit in opposite directions of each other only one side is being “painted.” When they looked closer an immense ring of thinly spaced soot-like powder 20 times the thickness of Saturn was revealed in orbit far out in space.
So fine were the particles that they can only be detected by their faint thermal radiation signature in orbit. Deep black in color, they individually collect just barely enough heat from the distant sun to distinguish the ring from the surrounding cold of space. According to Verbiscer, "The particles are very, very tiny, so the ring is very, very tenuous — and actually if you were standing in the ring itself, you wouldn't even know it. In a cubic kilometer of space there are all of 10 to 20 particles."
Article comments
— go to most recent comments1 - Jet Gardner
What; no astronomy buffs awake tonight?
2 - Cindy
Very interesting and well-written article, Jet. Amazing that scientists are still discovering such simple things as rings.
3 - Jet Gardner
Thank you Cindy, I think it's a sure thing that there's one around Jupiter and probably Neptune.
4 - roger nowosielski
Sorry, Jet. I am spent having argued all morning long with other scientists. You may not be aware of it, but Cindy here can vouch for me. I'm not lying.
5 - Jet Gardner
What Roger-no jokes about rings around Uranus? I'm disappointed!
6 - Fran
Very well written article Jet! I love astronomy. It is an area where science is rewritten, or at least theories are expanded all the time. Very refreshing!
7 - Jet Gardner
Well it's a case of sibling rivalry Fran, remember the fascination with Mimas when the huge crater was discovered and it was dubbed "the Death Star"? Phoebe had to do something to get the attention back on her.
8 - roger nowosielski
Sorry. I'm tired of arguing.
9 - Jet Gardner
There is no good arguing with the inevitable. The only argument available with an east wind is to put on your overcoat."
James Russell Lowell
10 - Dr Dreadful
Roger is the only person I can think of who'd even consider arguing about Saturn's rings...
11 - Jet Gardner
tell me about it doc!
12 - roger nowosielski
Thanks for the dig. But you'd rather I let you freakin' countryman off the hook. And thanks for third person comments.
13 - Jet Gardner
You know that deep down in my heart that I love you Roger
14 - Jet Gardner
The best way to overcome an opponent is to never let them suspect that you're anything but a blabbering idiot.
Jet Gardner
15 - roger nowosielski
Well, Jet, I had no idea that you ever regarded me as an opponent. In what respect? What issues should we be fighting about? [Personal attack deleted by Comments Editor]
So you tell me what my reaction ought to be?
16 - Ruvy
Good article, Jet,
I only noticed it now. Aside from "painting" moons (with a green cheese palette), of what significance do you think these rings might be?
Oh, by the way, real nice illustration. Jet'sArt.... Cool!
17 - Jet Gardner
Well Ruvy since we're talking 10-20 particles per square kilometer probably not a lot, however it did successfully explain how a moon can be half white and half black and come by it naturally.
18 - Dr Dreadful
it did successfully explain how a moon can be half white and half black and come by it naturally.
There's a Barack Obama joke in there somewhere, but I think I'll leave it to Archie or someone to have the bad taste to make it.
19 - STM
It's no longer politically correct to use the term "dwarf".
The headline on this should read: "Newly discovered Saturn ring vertically challenges all others".
I suppose you've heard about the latest dramas in Oz Doc that have also aired in the US and UK for a giggle at our expense??
1) The black-face row; a Jackson tune performed by former medical students on a "red-faces" section of a local TV show here. Except for the guy who was impersonating Michael, who is a plastic surgeon of Indian background who painted his face white. True. The others were all from different ethnic backgrounds. Perhaps it comes from us not understanding the background of black-face in the US.
2) In an effort to reduce alcohol-related problems at the V8 race at Bathurst, police and organisers restricted the allowable alcohol to be consumed per person to one case a day (24-30 cans)
3) The "midget racing". A "horse race" in which little people dressed in jockey outfits rode "big people" down the straight at a mtg in Victoria.
As usual, everyone is calling for others to "lighten up", but there might be some truth in suggestions that we aren't very politically correct down this neck of the woods.
20 - Dr Dreadful
I heard about the first two, Stan, but not the third. Priceless. Only 30 cans a day... how's a bloke to cope?
Such incidents pose an intriguing anthropological question. Did Aussie blokedom influence American redneckery, or vice versa, or did the two develop independently?
21 - Jet Gardner
I'm proud of myself for staying out of this
22 - STM
Aussie blokedom, despite the heavy emphasis on BEER and sport of the body-contact kind (and yes, folks, cricket IS a body-contact sport with 100mph rock-hard ball-shaped rockets bouncing into your head and just about every part of your body every minute or so) is possibly a little "gentler" than American redneckery.
It involves less wankery, less needless talking (and waaaay less gun-play) for a start, and our pick-up trucks are really hotted up cars, usually V8s, with a tub or tray and just a single driver and passenger cabin and are known as Utes (as in shoots), not trucks. They are like those NASCAR ones, but with the steering wheel on the proper side.
All I can say about this is that the modern ones go around corners a lot easier than the old ones used to, with the back end always in danger of sliding out if unloaded.
Who knows how it all came about. I suspect it's from the fact that we both had a "wild west". In our case, it was made even wilder by the fact that many of the outlaws were already criminals twice-over before they became outlaws.
So what's the excuse for your mob from the Old Dart, then? They love punching on, possibly with a beer glass in one hand whilst singing a hooligan song. The scourge of the highwaymen?? "Stand and deliver." "Right, cop this, then."
But, yeah, they are similar cultures. No hard-core Aussie bloke, especially someone from the bush, is going to walk into a real redneck bar in the US and feel a) any fear, or b) any discomfort. They'll just feel right at home.
And possibly vice-versa. Possibly ...
Mate, even Poms fit in down here.
Anyone fits in here, no matter where they're from. All you have to do is TRY to fit in, make the effort, and you're in.
23 - STM
And Jet, shame on you.
This is the kind of discussion you need to be involved in, even just as a distraction :)
24 - Jet Gardner
They have "utes" on Saturn?
25 - STM
If they don't, I won't be going there :)
Ring also means something else in Australia. We might indeed be one people separated by a common language.
Nice bit of artwork BTW. You did good on the whole piece Jet. Interesting stuff.