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Saturn Rings But No Spokes
An anonymous reader writes "Scientists continue to ponder why images of Saturn's rings today lack the 'spokes' or dark radial bands radiating outward and first observed on the Voyager flyby. The Boulder-based Cassini Image Team describes 5 visible moons, plans for the descent probe going into the Titan moon's hydrocarbon-rich atmosphere and the expected orbital entry around Saturn less than 4 months from now."
Are you sure it would send the right message?
It sort of seems to me like saying "unmanned exploration is really successful, but look at how many people we killed with stupid manned exploration, that could have easily been done unmanned".
I've had enough abrasive sigs. Kittens are cute and fuzzy.
I was wondering if the planetoid and particles could be doing the wave.
Generally these things are oblong rather than spherical. Maybe there is some gravitational coupling between the particle shape and Saturn and/or the other neighboring particles.
The particle could be spinning along their axes perpendiculr to the ring and along the line from the center of Saturn to the particle.
When the particles long axes are aligned perpendicular to the plane of the ring they would look one way (reflect less light perpendicular to the plane of the ring). Then when they rotate with the long axis in the plane of the ring they reflect more light perpendicular to the plane of the ring - they look brighter.
Admitttedly the dipole interaction would be pretty small. But this would allow for no spokes in the sense of ripples in the particle density but still allow us to "see" the spokes.
The Voyager images may be correct, but I'm playing skeptic until Cassini shows the same thing. Like I said in my original post, if image processing algorithms can show canals on mars, what makes you think Voyager's pictures are correct? If Cassini shows nothing, what does that prove? What about Hubble? I've said this above, but I'll say it again. If there is good corroboration between ground-based and space-based imaging, the image processing algorithms are normalized, and planetary geophysicists have a better bead on the magnetic field properties, I'll believe there is some real phenomena here.
Anything a robot can do, an astronaut in a space suit can do BETTER by several orders of magnitude.
I doubt that.
First: No astronaut likes to take 10000 examples and analyses them 10000 times. A robot doesn't complain. A robot doesn't get tired. A human does.
Second: A robot can be build adapted to the martian surface: A third the weight for the same mass, no breathable air, sandy environment... For a human, you have to put lots of technology into the space suit to adapt to the martian environment, and the astronaut is occupied carrying it around instead of performing experiments. And working in a space suit is not as easy as just with a labor suit.
Third: A robot can have everything builtin needed to perform analysis. You can design everthing in a size fit to the experiment you are planning. For a man you have to have everthing in the size a human needs it to handle. A human may not be able to perform all experiments during the walk outside, she has to carry her martian examples into the space station and work in the lab, which takes much longer.
The only thing humans are better than robot is to react at unexpected situations. But since the experiments are already preplanned on earth and the space ship is designed for and loaded with the equipment for exactly those experiments, humans don't have much chance to adapt to unexpected situations. What unexpected situations anyway? Suddenly a martian jumping at people? Basicly there are two types of unexpected situations a human could be forced to react on: a) something dangerous happens. Then be glad you just loose a robot. b) there is a chance to analyse something you didn't expect to be there. Then the human doesn't have the equipment to analyse either (and because we don't send McGuyver, he can't built it out of martian dirt). And there is still the earth station, and most of the robots are reprogrammable and remotely guidable anyway, so you may be able to adapt the experiment to the new situation.
With the ESA Beagle we had a situation where a human being around may have helped. She could just take the beagle probe and turn it back on after it failed somehow. But it's much cheaper to just send a second beagle probe to Mars than to send and bring back a human being.
About 30 seconds after posting the above I found this link, to an abstract of a scientific paper detailing Hubble observations of the spokes.
NASA really has to get the PR machine in motion
Please add one key adjective to your request: "NASA really has to get the honest PR machine in motion". It's one thing to try to make science and exploration more interesting to non-science people. It's another to spin every news story so it becomes unbelievable.
(I don't have a tinfoil hat. Really.)
The only thing humans are better than robot is to react at unexpected situations.
[snip]
What unexpected situations anyway? Suddenly a martian jumping at people?
Good one, because, as we all know, nothing unexpected ever happens in space.
Let's see...
PROBLEM: Dust buildup on solar panels
Robot: Screwed because no way to clean it off.
Human: Wipes dust off
PROBLEM: Martian dirt is sticky. Is it because of brine, or is it anelectrostatic thing?
Robot: Takes a closeup picture. Can't tell definitively. Debate ongoing.
Human: Reaches down, touches dirt with glove, has a closer looks, problem solved in two seconds.
Aside: what's the latest story on that dust? I haven't bothered to read up since the last 'brine' hypotheses hit the news.
PROBLEM: Dirt has a crust on it, want to take a look what's under the dust.
Robot: Fixes five wheels in place, while spinning the sixth to break the crust.
Human: Takes a spade...
PROBLEM: Crater wall is steep, interesting deposits halfway down (let's presume here).
Robot: Takes a zoomed-in picture but cannot climb down.
Human: Climbs down, samples deposits, locates water.
The presumption that we could build a robot with the same data-gathering capabilities as a human equipped with an array of scientific equipment is absolutely preposterous, at least in this day and age.
No astronaut likes to take 10000 examples and analyses them 10000 times
No kidding, that's what robots are best suited for, at least right now. Presumably, if any such activity were planned, the astronaut would bring an auto-sampling machine of some sort with them.
Maybe in the future we'll build robots that can gather data as well as a human, but that future is still a ways off.
Actually I believe it was the intertwined out rings that they saw ("two earthworms mating") when the reporter Roger and a couple other characters were at JPL viewing the Voyager images. The two narrow rings were being roiled by the Message Bearer's drive, but of course we didn't know that at the time :)
The same chapter does refer to the spokes, but (pulls out copy to check) Yup, in the Prologue: "Outside the broad main ring system, a narrower ring still roiled from the wake of Message Bearer's drive". The first indication that *Earth* had of the oncoming ship was when they detected it, however; nobody could explain the rings.
I thought it was a neat way to refer to the Voyager images...
SB
It's old. The more humans I meet, the more I like my cats. At least they are honest.
any crew embarking on such an expedition will be fully cognizant of the risks
Yeah, the same way those Shuttle crews were kept fully informed of aware of the risks by the NASA administration.
Dialectician. Archology.