Apparently the Cassini fly-by is going to be sooner than we expected...this is from Gary D. Goodwin of THE MILLENNIUM GROUP:

"On a recent update to the page I posted that the Cassini Flyby would be tomorrow night. Today NASA Updated that Flyby 24 hours to tonight at around 8:30 Pacific Time. Please see the NASA page for this updated message."

http://www.jpl.nasa.gov/cassini/MoreInfo/sigevents/sigevent990813.html

Heads up, kids!

LunaC

-- LunaC (LunaC@moon.com), August 17, 1999

Answers

Good. When that's over with, we can worry about the NEXT looming disaster.

BTW, can anyone explain what the worst case scenario is as regards Cassini? If it blows up, will we all get cancer in 20 or 30 years?

-- just one (thing@after.another), August 17, 1999.

Thanks for the heads up!

-- Johnny (JLJTM@BELLSOUTH.NET), August 17, 1999.

Why, why are they always trying to kill us?

-- Mara Wayne (MaraWAyne@aol.com), August 17, 1999.

The worst Cassini can do now is get lost like that Mars mission. They're too close now for even the worst possible course change to hit any part of Earth's atmosphere. I think the worst that could ever have happened wouldn't have been measurable anyway, despite the fear mongers' ranting and raving whenever they hear of anything related to radiation.

-- Flint (flintc@mindspring.com), August 17, 1999.

Thanks Flint,

I guess a little radiation exposure never hurt anyone, at least that is what the government told all those Native Americans that were hired to dig all that uranium a few years back. And, didn't we just have some postings about government sponsored uranium/plutonium processing plants where the bosses told the workers they could *eat* that dust if they wanted? So, how bad could it be, anyway?

-- Gordon (gpconnolly@aol.com), August 17, 1999.

news on radio today said it would pass "very close to earth" at 11pm. ( don't know who's time) Said if it hit thousand of miles would be effected. Don't know if it is true..just reporting what I heard.

-- Moore Dinty moore (not@thistime.com), August 17, 1999.

From the New York Times~

August 17, 1999

An Oddity in Space Baffles Experts

By JOHN NOBLE WILFORD

Every night at their telescopes, astronomers invite the universe to a battle of wits. Surprise us, they say, with some teasing wink of light, some few cryptic clues to something unfamiliar and, better yet, an implied challenge to a cherished theory. In most cases, astronomers boast, we will have it figured out by dawn.

Now astronomers have an unyielding mystery on their hands, something they have observed and pondered for three years, a point of light deep in the northern sky that appears to be like nothing seen before.

This may turn out to be only a curiosity, an odd variation of a familiar phenomenon, or it may be the first evidence of some unsuspected object with reverberating theoretical implications. Detecting planets around other stars is the most celebrated recent discovery to challenge scientists, forcing them to rethink their theories about the formation and dynamics of planetary systems and take more seriously the possibility of life existing elsewhere in the universe.

The mystery object has so far confounded astronomers because they cannot decipher the language of its light. Usually, by breaking down the spectrum of light into its component elements and charting the spikes and dips on a graph, astronomers can identify and describe an object within minutes.

In this case, however, astronomers are finding nothing familiar about the light spectrum, a couple of Everests representing emissions from the object surrounded by lower peaks and broad valleys of heavy elements that blot out the true contours of the object's nature. They are beginning to sympathize with archeologists who sought to read Egyptian hieroglyphics without the Rosetta Stone.

"I've never seen a spectrum anything like this, and I take spectra for a living," said Dr. S. George Djorgovski, an astronomer at the California Institute of Technology who is the leader of the sky survey that detected the mystery object.

Whatever the astronomers are seeing, it is probably not a star, at least not any normal star. The light signature of stars is much simpler than this object's. Nor is it a distant galaxy, which would have much different light patterns.

With little evidence and even less conviction, some astronomers speculate that the object is a quasar, one of the sources of tremendous energies at the farthest reaches of the universe where the enormous gravitational power of black holes presumably gobbles up surrounding matter. If it is a quasar, it must be a rare kind beyond current understanding.

"It doesn't look like a quasar to my eye, but I may be wrong," said Dr. Wallace Sargent, a Caltech astronomer and quasar specialist, who is also director of Palomar Observatory in Southern California, where the discovery was made.

So if it is not a normal star, galaxy or strange quasar, astronomers say, the most intriguing possibility is that the mystery object is announcing the existence of an entirely new cosmic phenomenon.

"But we must do everything to rule out the known before we postulate that we have discovered something really and truly new," Djorgovski said.

Mystification is likely to be a more common experience in astronomy as more powerful telescopes and instruments with improved sensitivity are used for systematic probes deeper into the universe and over broader stretches of sky.

Several comprehensive sky surveys under way or just beginning are expected to discover many rare or even previously unknown types of astronomical objects and forces.

Exploring the entire northern sky in different color filters, for example, the Digital Palomar Sky Survey, now nearing completion, has collected data on more than 50 million galaxies and about 2 billion stars. The census has identified more than 70 quasars at such great distances that they are being seen at a time when the universe was less than 10 percent of its present age.

One surprising discovery was a starlike light several hundred times brighter than the galaxy with which it was associated. Astronomers are not sure, but they suspect they were seeing the aftereffects of a gamma-ray burst, the most powerful events in the universe today.

First detected in the 1960s, gamma-ray bursts are examples of an astronomical mystery that is only now being solved.

For the survey, astronomers devised computer programs to sift through processed photographs for starlike objects, then distinguish the stars from galaxies and isolate rare points of light that are not immediately recognizable. This was how the new mystery object showed up.

Djorgovski and his team -- Dr. Stephen Odewahn, Dr. Robert Brunner and Roy Gal, a graduate student -- examined the object's light spectrum. Some of the lines of emissions, especially the two Everest spikes, looked too sharp to be from a quasar. They combed the star catalogs and published research papers, but found nothing like it.

A search in the archives of X-ray and infrared surveys failed to show anything in those wavelengths at the location where the object's visible light was detected. Radio antennas of the Very Large Array in New Mexico scanned the same patch of sky. They picked up only weak radio emissions from the region; many quasars have proved to be "radio loud."

"This was the first one of something new, and a complete mystery to us," Djorgovski said.

By this time in most investigations of strange sightings, the mystery would have been solved. In fact, it would probably have been explained before the observing night was over. In several decades of observations, Sargent recalled being stumped only once by a strange spectrum, which turned out to be light from an exploding star, a supernova, in the late stages of its evolution.

"We couldn't identify it for several hours," he said, "and that's a long time for unsolved mysteries."

The next step for Djorgovski's team was to photograph the object again and again. Some aspects of the spectrum reminded them of a supernova a few days after the explosion. But in the pictures, the light from the object did not die down, as it would as a supernova faded.

"The light doesn't vary, doesn't move and doesn't erupt," Djorgovski said, reflecting the team's growing bewilderment.

Other examinations ruled out the possibility that the object was an aging white dwarf star, where strong magnetic fields had distorted normal spectral lines. Comparisons with all other examples of peculiar stars also failed to suggest a solution.

It is not even clear from the spectrum whether the object is extremely far away or relatively close by. Distances are estimated by the shift of light to the red end of the spectrum, a sign of the object's velocity as it recedes from the observer in the expanding universe.

At this point, the Caltech astronomers started showing the puzzling spectrum to quasar and stellar astronomers elsewhere. In a presentation at the June meeting of the American Astronomical Society in Chicago, Djorgovski issued a challenge to all colleagues to help solve the mystery.

When he first saw the spectrum, Dr. Richard L. White, an astronomer at the Space Telescope Science Institute in Baltimore, surmised that this could be a subspecies of quasars. One small segment of the mystery object's spectrum looked a little like one small segment of a spectrum from what astronomers know as broad-absorptionline quasars. Some 10 percent of the known quasars fall into this category.

A spectrum of most quasars, White explained, is distinguished by broad lines of the light emitted by gases, mainly hydrogen, moving around the nucleus of the object. A small number of quasars, though, produce a spectrum with broad absorption lines, which dip low like the Dow Jones average on a bad week.

These dips record the absorption of some of the object's emitted light by intervening gases, hydrogen and sometimes heavy elements like carbon, magnesium and iron. The mystery object's spectral absorption line for iron was the one part that reminded White of a broad-absorption quasar.

"When I heard George give a talk, I bet the object is a broad- absorptionline quasar," he said. "For all I know, it could be something quite different. So much of the emitted light has been chopped away and completely obscured by the absorption lines that you can't recognize what it is you're seeing."

Djorgovski said he tended to agree with White that the mystery object was probably a rare kind of quasar. "We may find it's a sub-sub- subspecies of quasars for which there may be only one example," he said. Or it could be something entirely new. "We can't think we have discovered all the kinds of things there are out there," he added.

The strategy of conducting wide surveys of the sky with new telescopes is to make a census of the known universe, chart the outlines of large-scale structure like superclusters of galaxies and, through the sheer numbers of detected objects, discover new and unexpected phenomena.

In some of the first observations by the Sloan Digital Sky Survey, an even more ambitious undertaking begun this year, astronomers detected an entirely new category of dim, reddish objects that scientists are calling "methane brown dwarfs." These are objects sometimes called failed stars, smaller than a star and larger than a planet and, in this case, with atmospheres rich in methane.

"We are at the beginning of a lot of new surveys of the sky, with more data about more objects going into the computers," White said. "It would be really shocking if we didn't find new, strange objects."

---------------------------------------------------------------------- ----------

-- (this@is.interesting too), August 17, 1999.

Gordon:

Although your question is meant to be rhetorical, it has a pretty clear answer, measured in Roentgens. We all get "a little" radiation all the time. Pilots get more than their share. X-Ray techs used to get too much (since X-rays are cumulative) and so did Uranium miners and those who painted wristwatch dials. So we made lots of errors, we learned to calibrate dosages and relative dangers very well. And we *still* can't avoid all radiation. But below a certain dosage, the danger of radiation poisoning vanishes into the noise -- yes, it would kill you (50% chance) if you didn't die of anything else before you reached a few thousand years of age.

NOW, if the 72 pounds of plutonium were atomized into the atmosphere (worst case), the dosage for each person on Earth would rise infinitesimally -- you might as a result of such an accident die of radiation poisoning at age 4,000 rather than 5,000. This is of course a real hazard, somewhere on the danger scale between being hit by a meteor (less likely) and tripping over an armadillo and falling off a cliff (more likely). So a sense of perspective is required here.

However, given your position with respect to y2k, I can see the difficulty such a task presents to you. I suggest you look up these dangers and study them, just as a first step, OK?

-- Flint (flintc@mindspring.com), August 17, 1999.

From CNN story: http://www.cnn.com/TECH/space/9908/16/cassini.flyby/ ... The flyby at 11:28 p.m. EDT Tuesday will use Earth's gravity to change the probe's direction and speed relative to the sun.

-- Mr. Details (Details@detail.com), August 17, 1999.

Mr. Details:

As a very tiny detail, the change in Cassini's orbit will be matched by a change in Earth's orbit, for a net system (Cassini-Earth) change in angular momentum of zero.

-- Flint (flintc@mindspring.com), August 17, 1999.

AAAEEEEIIIII!!!!! I just finished reading "Lucifer's Hammer" and now I come upon this!!

arrrghhh!! 15 minutes left until the fly-by...to late to head for the hills.

*gulp* bye-bye guys...it's been...*snif*...fun.

-- Chris (%$^&^@pond.com), August 17, 1999.

ITS LONG GONE AND SPEEDING AWAY FROM EARTH

-- flierdude (mkessler0101@sprynet.com), August 17, 1999.

Phewww!

Remind me not to read End of the World books before the GPS EOW next week....

-- Chris (%$^&^@pond.com), August 17, 1999.

Flint,

What's this business about "given your *attitude* about Y2k"? Are you suggesting I have an attitude, and you do not? Are you patronizing me? Anyway, I have read quite a bit about radiation exposures, as you might imagine, due to my previous career. My current belief is that there is *no* safe exposure limit, none. No mini-roentgen, micro- roentgen, rad, rem, sievert, curie or bequerel acceptable limit. You might enjoy a book currently available titled Diet For The Atomic Age, by Sara Shannon, which is far more honest and accurate about this matter than the AEC or any "official" government source. Remember, they are likely to let you believe you can *eat* radioactive dust without concern. I know, I know, such a statement probably just came from some dumb-ass supervisor who didn't know any better. But in a government regulated facility like that, why doesn't *everybody* know the facts about the dangers? Huh?

Now, having said all that, I wish to compliment you on the bulk of your second commentary (ignoring the last paragraph). That's more like the kind of opinion I expect from you, rather than the quick blow off that you gave it on your first try. I still think you are making a mistake in minimizing it, but at least you didn't just wave it away with a "tut tut never fear" attitude. There's that word again.

-- Gordon (gpconnolly@aol.com), August 18, 1999.

when I was an activist, protesting the Trojan Nuclear Power Plant, back in 1977, I was convinced that even a gram of plutonium, caught in your lungs, would continuously blast a tiny area of your lungs until you had a very high chance of getting lung cancer, years later. Plutonium was touted as being the single most poisonous material in the world.

Has all this changed? I haven't been keeping up with it since Trojan was shut down.

By the way, Trojan's 1000 ton reactor was barged up the Columbia River, then taken cross country to Hanford, just about a week ago. Glad to see it leave my state (Oregon). Washington seems to welcome radioactive waste, for some reason.

Al

-- Al K. Lloyd (al@ready.now), August 18, 1999.

1. It's now gone past OK. It was probably known to be AOK on course for days beforehand if not weeks. The potential accident was that its control systems might have failed months ago, leaving its trajectory possibly hitting Earth with no possibility of correction.

2. They tested a lot of A- and H-bombs in the atmosphere back in the 50s and 60s. This vaporized and dispersed a lot more plutonium than the Cassini probe could have done. Not good, but not a catastrophe either.

-- Nigel Arnot (nra@maxwell.ph.kcl.ac.uk), August 19, 1999.

There have been many serious exaggerations of the Pu threat - to date, even those atomic energy workers who ingested significantly more than "a grain" (a gram is Hell of a lot of Pu dear sir! - it would not "fit" down your nasal passages, nor could a gram of Pu become airborne.) of Pu in industrial accidents in the fifties and fourties have found to suffer the kind of lung cancers you mention.

If swallowed, the waste is discharged from the intestines in 24-30 hours, and so does not cause significant doses even then.

Excessive radiation is not a "good" thing, but it is NOT a calamity.

-- Robert A. Cook, PE (Kennesaw, GA) (cook.r@csaatl.com), August 19, 1999.

Robert, I assume you meant to say that these workers HAVEN'T been found to suffer lung cancer?

Although I think I goofed about a gram (I don't remember the figure, to tell you the truth, and it may have been a single atom, for all I know) I believe you are incorrect to say a gram cannot become airborne. It all depends on how finely you grind it up (or blow it up) Actually I believe that NASA, or whoever launched the satellite, was successful in getting over 30,000 grams airborn AT THE SAME TIME!! :)

Strangely enough, I am listening to a news report from Paduka, where they are explaining how they have an unusual amount of cancer, and men keep dying of brain tumors in their 30's, allegedly from plutonium. (All Things Considered is the program I'm listening to--National Public Radio)

Some would have us believe that Plutonium is not a serious threat because we dumped so much more of it into the air through nuclear weapons testing that is contained in this satellite. But MAYBE one of the reasons that cancer is killing so many people these days is that there is so much plutonium in the environment, no?

Anyway, I think they should use solar power to power these things rather than playing target practice with our favorite planet

Al

-- Al K. Lloyd (al@ready.now), August 19, 1999.

Nice to consider as a theory, true. But from an engineering sense, at the time these were designed, given the "state of the art (then and now) in solar cells", and given the distances (and reduced solar radiation at the long distances needed, and given the power available to get hte whole thing up into orbit and then (form orbit) out into the trajectory needed - it just couldn't be done.

You have a choice of not doing the mission, or doing it this way. Since the planet orbits can't be delayed (then or now), the mission HAD to be launched and designed precisely to even use this sling-shot method to get out towards the outer planets.

Yes, the activists can discuss solar power, but they build the required power at the required time using solar power: no more now than they can power a Al smelter or oil refinery from solar power. It simply can't be designed that way, can't be built that way.

But they can talk about it - granted. It

-- Robert A. Cook, PE (Kennesaw, GA) (cook.r@csaatl.com), August 19, 1999.