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Cassini Greets Jupiter
Dr. Zowie writes "The Cassini probe, despite
predictions of doom
on launch and on its
Earth flyby, appears to be working just fine as it wends its way outward toward Saturn. It's currently flying by Jupiter for an additional gravity assist.
Today, the imaging team released their first high ('better than Hubble') resolution color images of Jupiter. I can't wait to write a Jovian screensaver..."
Halfway down that last page is a sweet movie (GIF or QT) showing time-lapse clouds around the Great Red Spot on successive rotations of our largest planet.
99 sites of stuff on the web,
99 sites on the web,
Slashdot one down,
into the ground,
98 sites of stuff on the web.
Please will someone who opposed the launch of the Cassini probe please reply to this message? I have something very urgent to say to you....
HA HA. U R DUM.
If tits were wings it'd be flying around.
Hubble's great-- but there's really no substitute for a flyby. The Voyager probes produced better pictures than Hubble, (as did, I suspect, some of the Pioneer probes). And then there was Galileo...
Hubble cannot take a picture of the Earth, Moon or Sun. Everything else is fair game... assuming no comets or large bodies come extremely close to it.
The joke would be funnier if it took into account that it's Earth's gravity that is reduced by the launch of Cassini (in direct proportion to the combined mass of probe, fuel expended, etc.), not that of any other extraterrestrial object. What Cassini is stealing from other objects is angular momentum. As it slingshots around various objects, the energy it derives is converted from planetary inertia to probe speed.
Hence, if we continue launching probes and using other planets to slingshot them up to escape speed, Venus (and other planets) will eventually spiral into Sol as Earth spirals outward toward Pluto.
MacOS, Windows, BeOS, GNOME, KDE: they're all just Xerox copies
What with Morton Thiocol rubber bands snapping and all that powdered magnesium on board for flash photography, that's the last time I'm talked out of using fulminate of mercury as the propellant!
--
A feeling of having made the same mistake before: Deja Foobar
"I will take the Ring," he said, "though I do not know the way."
(3) determine the nature and origin of the dark material on Iapetus' leading hemisphere;
Personally, I want to know the nature and origin of that large black monolith on the other hemisphere...
Someday, you're going to die. Get over it.
I remember the Cassini protests outside the whitehouse (from CNN). Some dude carrying around a poster "Our Last Sacred Space" with a drawing of an alien like on the X-Files. Like he thought we were polluting Saturn or something...
I checked out that anti-Cassini website under the predictions of doom link, and found that the author's primary complaint was that the 74 pounts of Plutonium might crash into the Earth. Maybe over Africa.
Let's see. Africa has 6,900,000 square miles or so. Seventy-four pounds of plutonium is about 34,000 grams. Assuming that Cassini broke up and only affected a third of Africa (2.3 million square miles), that's 0.014 grams of plutonium per square mile.
Frankly, I would think that the author of that website would be happy to have something that was dangerous and already here to be shipped out into eternity.
Some people just don't think.
Chivalry is not dead, it's just frequently misspelt. - M. Langley
Bingo Foo
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taken! (by Davidleeroth) Thanks Bingo Foo!
I've got all the jpg's and the .html page so far. The gifs are hard to get for some reason. I've edited a copy of the html page so that the img references point to my own mirror, but since all the inline images are the gifs, it doesn't look that good yet. If you click on the jpg links below the images, they are there. I'm not even gonna worry about the tiffs.
As always with my mirrors: This ain't my work. don't blame me for the problems with the content. I may have made slight changes to the html to make the images work on my machine. If you own or created this work, I'm just trying to do you a favor; if you don't want me to, just mail me. I usually pull these down within a while anyway.
as a non-republican conservative (i'm independent but voted bush, but that's another story) i listen to rush a bit. he is so full of himself it's not funny. half the quotes he cites these days are quotes of HIMSELF! now before anybody says 'hey, you're just one of those liberal whiners trying to discredit rush' (alright, probably nobody will say that because it would be retarded) i must repeat... I VOTED FOR BUSH AND I STILL HATE RUSH LIMBAUGH! okay. rant off.
"I hope I don't make a mistake and manage to remain a virgin." - Britney Spears
Detector design is an art, and these imagers are not the ones you buy in cameras at Wal-Mart or even in the back of amateur astronomy magazines. They are hand made one at a time and only the best of the best individual samples go into space.
These detectors are easily ruined. Long before the CCD melts its high sensitivity can be ruined as excessive temperature and radiation scramble these carefully arranged structures. They will still function as CCD's, but the characteristics which were achieved at such great cost will be ruined. This happened to a relative of mine back in the 70's when he was on vacation, and a coworker let the liquid nitrogen run out on one of his gamma ray detectors. It still detected gamma rays after its day at room temperature, but the energy peaks were broad and flat instead of nice and sharp as their research required.
The Hubble could focus on the Earth and Moon if the controllers wanted to risk trying, say, aiming at the night side. But they do not want to risk the usefulness of their detectors for faint deep-space objects on trying to resolve Neil's footprints.
Hubble did photog a near-earth asteroid awhile back that was passing at Moon-like distance, but I believe the problem with the Earth and Moon is the sheer size of highly illuminated area. And imaging a near-new Moon wouldn't help because, of course, then the Moon is mostly dark because the Sun is behind it.
Brackets contain world's first nanosig, highly magnified:[.]
I'd forgotten the correct term for this particular device, but it is technically a thermonuclear battery, as the breakdown of the plutonium results in thermic energy, which is converted to electricity by a very advanced thermopile.
This plutonium is glassified. Entrance into the atmosphere would likely create either single-molecular concentrations locally (remember, long way from space down to earth) or giant chunks. These giant chunks pose next to no hazard for three reasons: the radiation they generate can be stopped by a piece of paper, so if a kid doesn't eat them, you're fine. The US and other governments would be *very* interested to recover the core, as it is quite expensive and easily reusable (two known failures involving RTGs(correct term), and in one case, whole core reused, other case it broke into small pieces, but did not become dust). Three, the plutonium, after being glassified, is devilishly hard to turn into bomb-grade plutonium, as someone else has pointed out, that is a *higher* number isotope, so it can't be reduced, it must be augmented, and that is just as easy to do with Uranium-235, which is far more common. However, if one were to reduce part of this isotope to create an augmented amount, the augmented amount, assuming perfect efficiency, would still be no where near enough to create critical mass. If one were to attempt to reduce the plutonium to U-235 (I don't know if this can be done, just hypothetical), there still wouldn't be enough, because in nuclear bombs, there's no such thing as a small bomb. Even an extremely efficient multi-stage bomb uses considerably more uranium than that, not to mention the plutonium in the trigger and the deuterium and tritium needed.
The fact is that there isn't a single major risk factor associated with the use of this thing. These things have been investigated by every reputable environmental group and have been given a clean slate by all. However, future use is in doubt simply due to lobbying efforts by people who see nuke and go nuts. That's what's sad, because these things are incredibly cost-effective. The same amount of energy from a chemical source would be huge. One of these batteries can produce 500 watts for thirty years.
A society that will trade a little liberty for a little order will lose both and deserve neither. - Thomas Jefferson
Those pacemakers use plutonium encased in tungsten inside stainless steel. Testing on those things was extensive. They will survive bullets at point-blank range and cremation.
Today, people are horrified by the concept of an implanted nuclear device, but the track record of these holdovers from the 1950s is pretty good.
"As far as the other comment, that the Pu238 "can't" oxidize, well, I suppose that depends on a lot of factors. It isn't supposed to oxidize, just like launch vehicles aren't supposed to explode. Personally I think if they screwed up badly enough to hit the earth dead-on at 30K+km/h that it would be hard to imagine all the Pu remaining in solid form regardless of any attempts to protect it."
But you're utterly missing the point here. They're using plutonium dioxide. It's already oxidised, and it's not going to oxidise anymore. Period!
"People who do stupid things with hazardous materials often die." -- Jim Davidson on alt.folklore.urban
Is it just me or would anyone else not want to be caught up in that swirling mass on the surface there. :)
.ph0x
Meanwhile, my own efforts to launch a space probe meet with minor setbacks...
--
A feeling of having made the same mistake before: Deja Foobar
Probably a stupid and half-informed question, but here goes. Isn't hubble meant for taking pictures outside our solar system. A friend of mine, here's the half-informed bit, told me anything in our solar system would ruin hubble being "too bright", the idea being hubble is meant to view stellar bodies much further away... Sorry if it's a dumb comment but comparing this to hubble seems odd.
Inheritance is the sincerest form of nepotism.
Ok, the plutonium is gone.
Now let's tell those green folks about how gravity assist steals energy from Jupiter, and may cause Jupiter to fall into Earth's orbit!
I'm sure we can prove it with a few strategic Newtonian equations.
The Cassini Orbiter's mission consists of delivering a probe (called Huygens, provided by ESA) to Titan, and then remaining in orbit around Saturn for detailed studies of the planet and its rings and satellites. The principal objectives are to: (1) determine the three-dimensional structure and dynamical behavior of the rings; (2) determine the composition of the satellite surfaces and the geological history of each object; (3) determine the nature and origin of the dark material on Iapetus' leading hemisphere; (4) measure the three-dimensional structure and dynamical behavior of the magnetosphere; (5) study the dynamical behavior of Saturn's atmosphere at cloud level; (6) study the time variability of Titan's clouds and hazes; and, (7) characterize Titan's surface on a regional scale. The spacecraft was originally planned to be the second three-axis stabilized, RTG-powered Mariner Mark II, a class of spacecraft developed for missions beyond the orbit of Mars. However, various budget cuts and rescopings of the project have forced a more special design, postponing indefinitely any implementation of the Mariner Mark II series. Cassini is currently planned to take a similar tour of the solar system as did Galileo, referred to as a VVEJGA (Venus-Venus-Earth-Jupiter Gravity Assist) trajectory. Several opportunities exist for Cassini to make observations of asteroids, although exact encounters remain to be determined after the spacecraft has been launched as it depends on the launch date. Current plans call for an arrival in June 2004. Shortly after entering orbit around Saturn, Huygens will separate from the Cassini orbiter and begin its entry into the atmosphere of Titan. Cassini is then expected to make at least 30 loose elliptical orbits of the planet, each optimized for a different set of observations. Cassini's instrumentation consists of: a radar mapper, a CCD imaging system, a visible/infrared mapping spectrometer, a composite infrared spectrometer, a cosmic dust analyzer, a radio and plasma wave experiment, a plasma spectrometer, an ultraviolet imaging spectrograph, a magnetospheric imaging instrument, a magnetometer, an ion/neutral mass spectrometer. Telemetry from the communications antenna as well as other special transmitters (an S-band transmitter and a dual frequency Ka-band system) will also be used to make observations of the atmospheres of Titan and Saturn and to measure the gravity fields of the planet and its satellites
appears to be working just fine as it wends its way outward toward Saturn
Should have said: appears to be working just fine while it basically wends its way outward toward Saturn" Otherwise, you'd get a Wend without While error.
Have you read my journal today?
but i just can't resist:P. Cassini goes to Jupiter to get more stupider....
What's the danger of living in Denver compared to living anywhere else? Or is that just an arbitrary place you picked?
Higher altitude means slightly more exposure to radiation from space.
...phil
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
very true amongst the laity - they see such issues as black/white "plutonium"/"no plutonium" instead of a range of concentrations from "naturally occuring background radiation" to "reactor core", reasonably acceptable risks and potential benefits, etc. I went back home once to find the local yocals were all up in arms about a new school w/ a furnace emitting "carbon monoxide". When I asked about "how much CO, what concentrations were measured" it was met with incomprehension and restating that "they found CO in that new school" - pointing out that there is CO in the air we're breathing now, just a very small amount, does no good either. The herd got spooked and were stampeding and the politicos had to man the media machines to restore calm and reason. Gawd, I'm glad I'm not the plumber in that hickville.
try { do() || do_not(); } catch (JediException err) { yoda(err); }
Um. None of the forcasted cancers are ever going to show up, since the uncontrolled reentry of Cassini into the earth's atmosphere was a prerequsite for the cancers to happen, and Cassini didn't reenter the atmosphere. Or weren't you paying attention?
...phil
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
Oh, yeah.. :-)
Actually, I know Jupiter has little to do with Earth's tectonic plates. And the danger from plutonium batteries is less than that of your favorite room being in the basement.
how can excess photons damage anything nonorganic?
What has being organic got to do with anything? If you point the HST at the Sun (or any telescope w/o a proper filter for that matter) you will literally melt the CCD. (Think ants under a magnifying glass here). The HST contains a fail-safe program that automatically shuts the door if the telescope is pointing to within 20 degrees of the Sun to prevent damage to the cameras. Someone else mentioned that it is unable to image the Earth or Moon as well. This is true, I think, because they are too close - it can't focus on something that near.
Admit nothing, deny everything and make counter-accusations.
i suspect, contain an unlikely assumption that the Po battery on a spacecraft, would be fully 'atomized' or powderized on reentry to the atmosphere. however i would think that chunks and bits might survive intact(assuming that in the unlikely event the Ir capsule and ablative shield even broke open at all in the first place) and these would obviously pose considerable hazard.
"....from a meteor strike than from a failed mission with a thermo-nuclear battery."
Whoa! thermonuclear battery! i didnt even know they were invented yet! did you mean nuclear thermoelectric battery?....maybe?
- "Hear that?! The percolations are imminent! Cease your ingress!"
1. It used the Plutonium isotope 239, rather than the more common 235. Pu239 is more reactive (has a much shorter half-life) than 235; this makes it better fuel for an RTG but makes it much more dangerous if you inhale a particle.
2. It used an especially large amount of this especially dangerous isotope of Plutonium.
3. In addition to the at launch risks (of course launch vehicles never blow up, right? The Challenger crew will back you up on that one) Cassini had to make not one but two near passes by Earth, using it as a gravity handle in order to get out to the outer Solar System. Of course NASA would never drive a spacecraft into a planet, just look at the job they did of inserting Mars Climate Orbiter into its current, um, location.
In any case like all risk calculations in matters nuclear the thing comes down to a multiplication of very large risks by very small probabilities, and in this case NASA didn't blow up the launch vehicle or drive the spacecraft into the planet. Had they done either there is a good chance the RTG would have survived re-entry intact; it is designed to do that, just as the spacecraft is designed not to blow up or drive into the planet, and usually those designs work.
However, there is a possibility that, in the unlikely event of a re-entry (particularly being driven into the planet during a gravity-handle exercise) the RTG would have breached. This would have been a very bad thing. Plutonium oxidizes readily into a very fine powder which can remain suspended in the air for amazing periods of time. Inhaling even one microscopic particle of this stuff (much worse than Pu235, which is bad enough) pretty much dooms you to lung cancer, at a minimum. You can argue with this if you feel like looking foolish but it's well known what happens when a particle of Pu gets embedded in lung tissue; every alpha particle passes through several hundred cells before it stops, and eventually one of them is going to do major mischief.
Now, if this happened it's likely that life would have gone on for most of us just as it has gone on after Chernobyl and Three Mile Island -- both accidents which have a long anecdotal and statistical history of ensuing mortality, which has been whitewashed, swept under the rug, or very occasionally outright covered up (ever try to get by-county infant mortality stats for Pennsylvania the year after TMI?). But it would indeed not be the End of the World (tm).
Is the smallish risk of that worth the pictures we're getting now? I am personally inclined to say yes. But then, it would probably be someone else who got lung cancer if the worst-case accident happened. The people who protested the mission have their point, which is that it's not my right to make that decision for them. I may not agree with them but that does not make them stupid or venal, and it's tiring to see the people I supposedly agree with taking the moral low road by making fun of them and refusing to get their point.
Brackets contain world's first nanosig, highly magnified:[.]
I guess Kubrick was wrong: there's no sign of the black monoliths.
I watched C-beams glitter in the dark near the Tannhauser gate.
Did anyone else see something strange in the Jupiter photos? A black object floating near Jupiter? Kinda like a long rectangle, black, no visible surface features. Looks like a large Hershey bar...
www.matthewmiller.net
"Live Free or Die." Don't like it? Then keep out of the USA
With all due respect, I wonder how even 120 people could contract fatal cancers. I guess, if someone used a linear, no-threshold model of radioactivity's effects and applied it to the entire population of the world. But realistically, the biggest danger from those RTGs was if one re-entered and hit you on the head. It wouldn't be pretty, but it wouldn't be cancer, either.
I remember how the media really pushed the controversy in the days leading up to Cassini's launch. CBS had footage of this one poor girl (she may have been around 14), crying in absolute terror as Cassini launched because she honestly believed all life on the planet was about to end. That was the product of the scare-mongering that people pushed. I wonder how many people worked themselves into genuine stress-induced problems because of the alarmist hand-wringing by the anti-nuke crowd.
NASA commented on it's use of "free" Jovian gravity claiming that "By allowing space probes to use gravity, more consumers would be exposed to it and therefore more interested in its use / application. We also give a venue for the discovery of new massive objects and help them advertise the fact that they too produce gravity...", NASA made no furthur comments...
Capt. Ron
crazy dynamite monkey
Cassini: I beg your pardon, but you wouldn't happen to be Jupiter, would you?
Jupiter: Why, yes.
Cassini: Nice to meet you! I'm Cassini.
*sniff* You know, these probes make the solar system a kinder, gentler place to live... chokes ya up, don't it?
Ceci n'est pas une sig.
The actual danger of a Cassini probe accident to a given person in the probe's disaster area is similar to moving to Denver for a year. These anti-nuke guys simply hype up the fact that plutonium is toxic without taking into account the fact that the toxicology of a single particle is minute and one has to have a significant amount inhaled in order to suffer any significant result. I did a report in college on this particular matter (Cassini had not yet been launched), and my report, which I no longer have, concluded that Cassini posed no significant threat whatsoever and demonstrated that my findings were backed up by the findings of several of the less-rabid environmental protection groups.
As a matter of fact, one is far more likely to die from a meteor strike than from a failed mission with a thermo-nuclear battery.
A society that will trade a little liberty for a little order will lose both and deserve neither. - Thomas Jefferson