Tom Van Flandern writes:
Solid rocky asteroids do not produce comae and tails, Van
Flandern. That simple visual distinction between comets and
asteroids has been around for decades. You are aware of the June 14
outburst, are you not? Rocky asteroids don't have those.
You've removed context, Van Flandern. Let's reinstate it:
As a professional astronomer, you are supposed to be
familiar with the viable, peer-reviewed, published models still on the
scientific table in areas where you claim some expertise.
That's rather ironic, coming from someone who had to change his
NEAR prediction about satellites around Eros, because he was not
familiar with the elongated shape (known for decades) and the
instability of some orbits around such an object (known for years).
Here is what you should know from reading the published papers on
this model and the Tempel 1 predictions paper on our web site: The EPH
predicts that debris clouds from the explosion will be trapped in orbit
around fragments.
That's what led you to predict a debris cloud around Eros, Van Flandern,
at least until after the flyby images didn't show any debris cloud, at
which point you changed your prediction, and explained that the elongated
shape of the asteroid made some orbits unstable. But Tempel 1 is also
elongated, so why should it have a debris cloud, Van Flandern? Aren't
those orbits also unstable?
Of course, the more distant orbits are still stable, so why didn't the
presence of distant satellites remain in the Eros prediction? Oh, that's
right; the flyby images didn't show any of those either.
Each debris cloud then evolves in mostly predictable
ways, depending on the forces it is subjected to. E.g., tidal forces
move the larger bodies away from the synchronous orbit. Smaller debris
(e.g., the size for a typical meteor) is removed by solar radiation
pressure if the nucleus spends too much time near the Sun. That is why
asteroids don't have much dust and gas left. Comet tails are generated
by radiation pressure on the whole coma, including the nucleus, not by
outgassing from the nucleus alone.
If radiation pressure removes the smaller particles, then why are there
any smaller particles left around a comet nucleus, Van Flandern? Doesn't
it need a source to resupply the smaller particles, Van Flandern?
You've removed more context, Van Flandern. Let's reinstate it:
The second
link above cites papers covering the history of the Satellite Model (SM)
for comets, a corollary of the exploded planet hypothesis (EPH), all the
way back to the original publication: "Do comets have satellites?",
Icarus 47:480-486 (1981).
Non sequitur, given that the EPH is not a viable model.
Pointlessly argumentative and uninformative.
That you are unable to see the point is your problem, Van Flandern, not
mine.
You've removed more context, Van Flandern. Let's reinstate it:
The EPH/SM model agrees that rocky asteroids do not produce
comet comae because comae do not come from the nucleus.
Irrelevant; the issue is not where the comae come from. The issue is
the visual distinction between objects called "asteroids" and objects
called "comets". Tempel 1 has a coma, therefore it is called a comet
and not an asteroid. Your prediction that Tempel 1 is a solid rocky
asteroid was therefore wrong before you even made it.
Pointlessly argumentative, or shows ignorance of the EPH/SM model
you are addressing. See preceding description.
That you are unable to see the point is your problem, Van Flandern, not
mine.
But I expect that you will continue to play your little game
of semantics in a feeble effort to maintain support for the EPH.
Ad hominem, argumentative, unscientific.
I'm well aware that your little game of semantics is unscientific,
Van Flandern. No need to tell me.
They are debris clouds from the original explosion event,
trapped inside the gravitational sphere of influence of the comet
nucleus.
Illogical, given the occurrence of outbursts.
Unexplained,
So, you admit that the EPH does not explain how outbursts can occur.
Progress. The icy dirtball model has no such problem.
but apparently shows ignorance of the model it addresses.
To which model are you referring, Van Flandern?
If a probe can cause an outburst, so can a meteorite.
Just how many 370 kg meteorites do you think hit a target smaller than
10 km in diameter over the span of a few weeks, Van Flandern?
But I'll note that you've carefully avoided mentioning
anything about the elongated shape of the comet.
Did you ever read the prediction article? Even its abstract
mentions the elongation.
It doesn't mention why the "debris cloud" exists for Tempel 1 despite
the elongated shape, Van Flandern. It doesn't mention why a similar
"debris cloud" didn't appear around Eros, Van Flandern. All it says
is that the local gravity field is unstable for large satellites, having
been removed by tidal forces. Does that mean the local gravity field is
stable for small satellites, Van Flandern? Why didn't we see any small
satellites around Eros? After all, you did predict satellites of all
sizes. If only the large ones able to raise tidal forces were deorbited,
then you have no reason for the smaller ones to be absent. Yet they were
absent.
See http://metaresearch.org/solar%20syst...DeepImpact.asp.
Does it differ from what you sent Benny Peiser, Van Flandern?
That comae are of this nature is confirmed by the model's
past successful predictions: satellites of asteroids, satellites of
comets, salt water in meteorites, sodium (derived from salt) in the
tails of comets, "roll marks" leading to boulders on asteroids; the
time and peak rate of meteor storms and outbursts; explosion
signatures for asteroids; strongly spiked energy parameter for new
comets; distribution of black material on slowly rotating airless
bodies; splitting velocities of comets. See citations at the second
link above. Especially, the meteor storm predictions and the
"split"-comet separation speeds as a function of solar distance could
not have been correctly predicted if the model was wrong because no
adjustable parameters or ad hoc helper hypotheses were used as aids.
Once again, you've ignored the model's unsuccessful
predictions, like satellites of all sizes around Eros.
Have you even read the thread you are posting in?
Of course, Van Flandern. I could ask the same question of you, considering
how much material you omitted from your follow-up.
Or are you just trolling?
That's rather ironic, coming from the person who started the thread.
I'm merely responding to you, Van Flandern. If you can't take the
heat, get out of the sunlight.
You've removed more context, Van Flandern. Let's reinstate it:
It is not really relevant here, but you should also know,
contrary to what you claimed, that asteroids have been known to suddenly
flare up and produce comet tails, further blurring the distinction
between asteroids and comets.
It is not really relevant here, but you should also know, contrary to
your usage of the terms, that comets can be inactive when far from the
Sun, thus producing a stellar (or should I say asteroidal) appearance
through the telescope. Gee, where did the debris cloud go?
On the few occasions when very deep images were taken, the coma
remained present even for comets out near the orbit of Uranus - e.g.,
Hale-Bopp & Haley.
Are you claiming that a distant comet was never seen to be completely
stellar (or should I say asteroidal) in appearance, Van Flandern, even
with very deep images?
By the way, I'm not familiar with any comet "Haley", unless you're
referring to some musician on Earth. I am aware of an outburst on
comet Halley at something like 14 AU. Is that what you're referring
to as "remaining present" near the orbit of Uranus?
It "disappears" only for observers with inadequate telescope power.
How convenient. Anytime someone fails to see the "debris cloud" around
a comet, you blame it on inadequate telescope power. Well, shouldn't
it be possible to compute the brightness and extent of the "debris
cloud" and predict its detectability at all heliocentric distances?
Perhaps you'd like to explain why some comets brighten and then fade
with a larger exponent than the simple inverse square law would predict.
Or perhaps you wouldn't.
You've removed more context, Van Flandern. Let's reinstate it:
Two asteroid-comet transition objects are known.
I see that you're behind the times, Van Flandern. Ever hear of
(7968) Elst-Pizarro, otherwise known as comet 133P/1996 N2?
"As a professional astronomer, you are supposed to be
familiar with the viable, peer-reviewed, published models
still on the scientific table in areas where you claim
some expertise."
--Tom Van Flandern
Both ironic and amusing.
Note: no response.
[See section 3 at
http://www.ss.astro.umd.edu/IAU/comm...eport97.html.]
The most famous [dual identity asteroid/comet] is asteroid
4015 = Comet 107P/Wilson-Harrington.
[Tholen]: Whose cometary nature hasn't been seen since its discovery
in 1949. When rediscovered as an asteroid in 1979, I observed it
during the Eight-Color Asteroid Survey and classified it as an CF-type
asteroid.
You've removed more context, Van Flandern. Let's reinstate it:
But of course you knew that, given that professional astronomers are
supposed to be familiar with the peer-reviewed literature in areas
where you claim some expertise.
And your point is?
My point should have been obvious, Van Flandern. I guess you were too
busy removing the text that you didn't want to address, like your
unfamiliarity with the Elst-Pizarro case.
My point was that when asteroids suffer an
impact, they look just like comets until the debris settles or is blown
away by solar radiation again.
Gee, why don't comets look like asteroids after the debris settles or
is blown away by solar radiation again, Van Flandern? Or do you intend
to argue that comets keep suffering impacts, whereas asteroids do not?
You've removed more context, Van Flandern. Let's reinstate it:
The Dirty Snowball model itself makes no specific prediction
(although individual advocates are betting on various possible
outcomes), but instead has an accommodation ready for whatever is
found. In science, this is known as "shooting an arrow into a target,
then painting a bull's eye around the arrow"
Sort of like the EPH predicting satellites of all sizes
around Eros, finding none, and then painting the EPH around the
boulders found on the surface. Ostensibly due to the unstable nature
of some of the orbits around an oddly shaped body. Except that the odd
shape had been known for decades, and the instability of some of the
orbits almost as long.
The original prediction that asteroids would have satellites
dates to the first "Asteroids" volume in 1979.
I see that you've left out some adjective, Van Flandern. The
prediction was not merely that asteroids would have satellites, but
rather that they would be commonplace. The adaptive optics searches
for satellites of main-belt asteroids are succeeding in less than 5
percent of the cases. Not exactly my idea of "commonplace".
Pointlessly argumentative.
Is that the best rebuttal that you can come up with, Van Flandern?
That you are unable to see the point is your problem, Van Flandern,
not mine.
My dictionary says: "commonplace: something ordinary; something that is
encountered or seen often, or that happens often."
Satellites of asteroids certainly aren't being encountered very often,
Van Flandern.
At the time, satellites were considered to be
non-existent or at best rare, freakish phenomena.
By whom, Van Flandern? If they were considered non-existent, then why
were astronomers looking for them? I participated in numerous asteroid
occultation experiments. We were always looking for secondary events.
Why would we do that if we considered satellites to be nonexistent?
You can't make a scientific argument by telling others what they
considered to be the case when in fact that wasn't what they considered
to be the case, Van Flandern.
5% is commonplace by comparison.
According to whom, Van Flandern? You?
And that percentage is a minimum because we can presently
discover only the largest instances of asteroid satellites.
No, it's not a minimum, Van Flandern; the minimum would be the actual
discovery rate, which is less than 5 percent for the main belt. It's
closer to half that.
But Hayabusa will be getting to Itokawa in just a few weeks.
When can we expect your prediction for it, Van Flandern?
Not enough is known about this asteroid's gravity field (to my
knowledge) to determine whether stable satellite orbits exist.
"As a professional astronomer, you are supposed to be
familiar with the viable, peer-reviewed, published models
still on the scientific table in areas where you claim
some expertise."
--Tom Van Flandern
Both ironic and amusing.
Not only have extensive lightcurve observations been obtained of the
target asteroid, radar has been bounced off it as well. The rotation
period is roughly 12 hours. The axis of rotation is nearly orthogonal
to the ecliptic plane. The dimensions are roughly 600 by 300 meters.
Is that enough for you to make a prediction, Van Flandern?
Estimates of a 2-to-1 elongation leave the stability matter ambiguous.
Why?
I therefore
make the same prediction as for Eros: Several satellites in orbit, or
lying on the surface with roll marks.
Covering all bases, eh Van Flandern? What you want is a prediction
that distinguishes your EPH from what you like to call "mainstream"
models, Van Flandern. Anything else isn't going to help your cause.
BTW, where are your predictions for Tempel 1 and Itokawa, Tholen?
Scientific fact does not depend on the presence or absence of
predictions, Van Flandern. Let it suffice to say that I have
participated in the planning for a satellite search around Itokawa.
Unfortunately, the experiment is necessarily severely limited by
the bandwidth of the downlink. Full resolution images are needed.
If you want to cover the entire Hill sphere, the observations will
necessarily be distant, thus making the smallest objects hard to
see. Being closer in would enable the observations of smaller
objects, but then multiple images would be needed to cover the entire
Hill sphere, but the bandwidth is inadequate to transmit that many
images without compromising other science.
You've removed more context, Van Flandern. Let's reinstate it:
It became specific in
1991 when I predicted that spacecraft would find at least one satellite
at one of the first three asteroids visited. That was repeated in my
1993 book, "Dark Matter, Missing Planets and New Comets". The prediction
was fulfilled by the discovery of Dactyl orbiting Ida in 1993. Many more
cases have been found since then.
The number of negative cases outnumbers the number of positive cases
by a factor of several. I see that you avoided mentioning that fact.
Note: no response.
But even those 1991 and 1993
predictions contained the caveat that, for unstable gravity fields or
asteroids involved in collisions, satellites would be found as boulders
on the surface, accompanied by roll marks to indicate their grazing
decay from satellite orbits.
Didn't stop you from predicting satellites of all sizes around Eros,
whose elongated shape had been known for decades.
Note: no response.
Reports of possible secondary occultations during the 1973
Eros-star occultation event led me to be optimistic that Eros had a
stable gravity field and satellites still in orbit.
Which says something rather significant about the
reliability of secondary occultation observations, something that
you've hung your hat on (so to speak) for other asteroids, like
Herculina.
So you think the 5-second secondary occultation of a bright star
91 seconds before its 20-second occultation by Herculina, reported by an
experienced occultation observer in California and confirmed
photoelectrically by two experienced professionals at Lowell
Observatory, was unreliable?
The zenith distance at Lowell was something like 88 degress, as I
recall. Weren't the Lowell professionals also skeptical, Van Flandern?
I'm sticking by my original assessment - it was a satellite.
Where's the satellite of Eros that produced the secondary occultations,
Van Flandern?
Herculina probably has a ring of satellites, which
would certainly frustrate any adaptive optics efforts to resolve them.
Why would a ring of satellites frustrate adaptive optics, Van Flandern?
Here's another chance for you to take a position. Do you have one
on this issue?
To which issue are you referring, Van Flandern? I wouldn't expect
a ring of satellites to frustrate adaptive optics. That's my position
on that issue.
You've removed more context, Van Flandern. Let's reinstate it:
But I learned of
1995 and 1996 Scheeres papers showing that the satellite orbits around
Eros were unstable because of its elongated shape only a year before the
encounter, in 1999.
"As a professional astronomer, you are supposed to be
familiar with the viable, peer-reviewed, published models
still on the scientific table in areas where you claim
some expertise."
--Tom Van Flandern
Both ironic and amusing.
Note: no response.
So I amended the prediction accordingly, well before the
results were known.
On what basis do you make that claim, Van Flandern? By
"results", are you talking about the rendezvous? Let's not forget that
the originally planned rendezvous failed due to an aborted engine
burn. The flyby imaging revealed no satellites, something that was
reported at the time.
Yes, I was talking about the rendezvous. So what's your point?
That you are unable to comprehend my point is your problem, Van Flandern,
not mine. But let me spell it out for you: your amendment was made after
the results were known, not well before, contrary to your claim.
Larger satellites tend to evolve tidally at the most rapid rate, so
smaller ones are more likely to survive. The original distant flyby
could detect satellites only down to an estimated 50 meters, with poorer
limits for close-in satellites.
And nothing was seen. After that, you amended your prediction.
Fireballs in Leonid meteor storms are
said to arise from 1-2 meter bodies escaped from the parent comet. That
is still a pretty significant mass, so the distant flyby from the
aborted rendezvous was not sampling potential satellites covering five
orders of magnitude of mass in the range of chief interest.
Yet the results were good enough to force you to reconsider your
prediction, Van Flandern.
The 2000 encounter results were then reported at
http://metaresearch.org/solar%20syst...ngeResults.asp,
showing that the prediction amended the previous year was correct.
You have a peculiar notion of "correct", Van Flandern.
Argumentative and uninformative.
That you are unable to comprehend the information is your problem,
Van Flandern, not mine.
Neither you nor any other astronomer accepted my prediction
challenge.
Which prediction challenge would that be, Van Flandern? The
original one, or the revised one? You're a moving target.
Irrelevant because you did not accept either, and pointlessly
argumentative.
That you are unable to comprehend the point is your problem,
Van Flandern, not mine.
But let's take a look at your latest prediction. Benny
Peiser circulated on CCNet your message to him, which included:
"The impact will leave a small, shallow crater perhaps
10-20 meters in diameter."
--Tom Van Flandern
Now for JPL News Release 2005-113, circulated by David Morrison in his
NEO News:
"Scientists say the crater was at the large end of original
expectations, which was from 50 to 250 meters (165 to 820 feet)
wide."
Is that the best you can do?
Is that the best rebuttal you can come up with, Van Flandern? The JPL
news release says that the crater is much larger than you predicted,
Van Flandern.
The quick rise in ultraviolet light
indicates the probe hit a hard surface
Non sequitur. I was talking about your prediction of crater size,
Van Flandern, not the strength of the surface.
... possible crystalline silicates
Non sequitur. I was talking about your prediction of crater size,
Van Flandern, not the composition of the surface, which is consistent
with the icy dirtball model.
... large surface craters
Non sequitur. I was talking about your prediction of crater size
made by the impactor, Van Flandern, not the sizes of other features.
... possible layering
Non sequitur. I was talking about your prediction of crater size,
Van Flandern, not the stratigraphy of the comet.
... overall appearance indistinguishable from an asteroid
Non sequitur. I was talking about your prediction of crater size,
Van Flandern, not the appearance of the comet.
... no increase in water emission or other volatiles
Non sequitur. I was talking about your prediction of crater size,
Van Flandern, not the lever of water emissions.
... evolved surface with dust not coming from inside
Non sequitur. I was talking about your prediction of crater size,
Van Flandern, not the evolutionary state of the surface.
... no new jet formed
Non sequitur. I was talking about your prediction of crater size,
Van Flandern, not the formation of new jets.
... These already-announced findings
all correspond to the prediction that Tempel 1 is an asteroid with its
coma not yet blown away by solar radiation,
Interesting that you didn't provide any reference to these "already-
announced findings", Van Flandern. But even if you had, it wouldn't
change the fact that they're all non sequitur to the issue of crater
size.
and several of these points
were mentioned explicitly in my prediction article referenced on CCNet.
Non sequitur. I was talking about your prediction of crater size,
Van Flandern, not your other points.
Regarding the crater size, the words used, "still analyzing", mean
they haven't seen the crater yet, but just the ejecta layer from the
crater, which is naturally considerably larger than any crater itself.
Conservation of mass, Van Flandern. The material ejected into space
had to come from somewhere.
The dust blasted into space was more opaque than the team anticipated,
making crater visibility problematic.
I pointed that out to colleagues shortly after they showed the movie
of the plume casting a shadow, Van Flandern.
So far, unless fancy image
processing can bring the crater walls out of the noise, they have seen
only a large black spot from crater ejecta (relatively black because the
probe targeted the brightest spot on the surface). Strength-dominated
comet models are still very much in the running, and I stand by my
small-crater-diameter prediction.
Does that mean that if the final analysis confirms a crater size at the
large end of original expectations, you'll declare the EPH as a failed
model, Van Flandern?
What's your prediction?
Scientific fact does not depend on the presence or absence of
predictions, Van Flandern.
Do you have an opinion of your own?
Opinions are irrelevant, given that what we're after is scientific
fact, Van Flandern.
You've removed more context, Van Flandern. Let's reinstate it:
The only one who even negotiated terms bowed out when I added the caveat
about decayed moons on the surface.
Why would anybody want to negotiate terms with someone who
doesn't stick to his predictions?
Argumentative and insulting.
You're the one who changed his prediction about Eros, Van Flandern.
If you find it insulting for someone to note that you changed your
prediction, then perhaps you should consider not changing your
predictions, Van Flandern.
You've removed more context, Van Flandern. Let's reinstate it:
But the prediction was in place and
was correct a year before the February 2000 encounter, when the first
boulder and roll mark were found.
The original prediction about satellites of all sizes was in place
and incorrect at the time of the satellite imaging effort during
the original flyby.
Note: no response.
How does that count as "painting the bull's-eye around the arrow"?
See above.
Note: no response.
Is there anything about my present prediction that Comet
Tempel 1 would have a solid, rocky nucleus that you find to be ad hoc
or like painting the bull's-eye around the arrow?
We'll have to wait and see how you change your prediction to
accommodate the actual data, the way you did with Eros.
Ad hominem, insulting, argumentative,
You're the one who changed his prediction about Eros, Van Flandern.
If you find it insulting for someone to note that you changed your
prediction, then perhaps you should consider not changing your
predictions, Van Flandern.
unscientific,
I agree that the changing of predictions in response to actual data
being received is unscientific, Van Flandern. No need to tell me
about it.
trolling.
That's rather ironic, coming from the person who started the thread.
I'm merely responding to you, Van Flandern.
Or do you give no credit to models you disfavor, regardless of
their success at making genuine predictions that other models can't
make?
What success are you referring to, Van Flandern?
The list in the paragraph above set off with four asterisks: ****
.... ****.
No more successful than the "mainstream" models you disfavor, Van
Flandern, and a failure at predicting satellites of all sizes around
Eros.
So do you have anything to say that might aid the search for truth
about which model describes nature better?
You're erroneously presupposing that I haven't already said something
to aid in the search for truth, Van Flandern.
Or is that not an interest of yours? -|Tom|-
"Ad hominem, insulting, argumentative, unscientific, trolling."
--Tom Van Flandern
How ironic.