PLEASE NOTE:


*

WORKSHOP FOR MITIGATING THE EFFECTS OF PUBLIC CONCERN ON THE NASA
BUREAUCRACY:
TWO DAYS IN WASHINGTON, 2002

>From E.P. Grondine <epgrondine@hotmail.com>

Hello Benny -

Last week I spent two days at the "Workshop on Scientific Requirements for
Mitigation of Hazardous Comets and Asteroids". As after my study of the
Bazas impact I was rather tired, I estimated that 2 days of this would be
just about as much of it as I could stand. As it turned out, it was more
than I could stand.

Tuesday morning I had received the abstracts which contained Morrison's
entirely misleading  estimate of the impact hazard: you know the one, the
one where Morrison takes the lowest estimate of the number of large
asteroids which he can find, uses that and some means to estimate the total
numbers for smaller asteroids, which in fact are completely unknown, and
then "forgets" to add in the impact hazard arising from comets, which appear
to have been responsible for about 50% of the recent impacts, and are
implicated in a large number of Extinction Level Events. About the only
question left was how the Workshop was going to be manipulated to give this
fraud the guise of scientific respectability. The answer came Thursday
afternoon.

Since NASA management already has in hand a report by a skilled engineer on
exactly how to deal with the impact hazard, a report which NASA is doing its
best to ignore, the event more properly should have been called the
"Workshop for Mitigating the Effects of the Public's Concerns on the
Bureaucracy". This should come as little surprise to you, as as an
anthropologist you are well aware the primary goal of any social
organization is its own survival. That said, let's start at the beginning...

"I DID NOT HAVE SEX WITH THAT WOMAN."

Another principle of which you are aware of as an anthropologist is that the
goal of any ritual, any meeting such as this one, its outcome, is fairly
well planned in advance. Thus to determine a meetings's goal it is very
important to determine exactly who organized the meeting and how it came
about. The search for an answer to this simple question took a day and a
half and produced some interesting results:

Monday Evening: "Mike Belton had been concerned about this problem for some
time, and he contacted NASA, and NASA thought it would be a good idea." - a
NASA employee whose identity will be protected.

Wednesday Afternoon: "Mike Belton had been concerned about this problem for
some time, and he contacted NASA, and NASA responded." - a NOAA employee
whose identity will be protected.

Thursday Morning, question by EP to Ed Weiler:
EP: "Would you care to guess how many Congressmen and Senators share the
public's misconception that dealing with the NEO problem is NASA's sole
responsibility?"
EW: "For your information, I have been contacted by exactly one Congressman
about this."
EP: "Who was he?"
EW: "I prefer not to say."

Thursday Afternoon, extract from response by Mike Belton to issue raised by
EP:
MB: "When Ed (Weiler) was contacted by several Representatives on this, and
he asked for my help."

Ahem... Well, Benny, perhaps Weiler mis-spoke to Belton, or perhaps Belton
simply mis-heard him.  In any case the members of the House Space
Subcommittee know full well exactly how many of them have spoken to Ed about
this, or they can easily establish that number quickly over lunch. I have no
reason to doubt Mr. Belton's memory of events, given the sincerity of his
concern with the impact hazard.

>From the plan which was sprung of Workshop participants late on Thursday
afternoon, which undoubtedly was formed with Weiler's full participation,
what appears to have occurred was that Dr. Weiler was contacted by several
members of the Congress about how NASA is dealing with or rather failing to
deal with the impact hazard. Dr. Weiler then planned and organized a
conference which would give a shroud of scientific respectability to his
previously arrived at policy decision that the Next Generation Space
Telescope would remain a toy for the astrophysicists, instead of part of a
reliable NEO detection system. It is also likely that Dr. Morrison's desire
that funds not be diverted from the programs at Ames in support of manned
Mars flight are reflected in the unrealistically low impact hazard numbers
which were foisted on the Workshop's participants late on Thursday
afternoon.

(Note that Weiler let the contract for the Next Generation Space Telescope
on Tuesday at a cost of some $828,800,000 for its construction alone, not
including its launch and operation costs, to give you some perspective on
the $3,900,000 per year that NASA intends to spend on NEO detection.
Undoubtedly that contract contains severe cancellation penalties, the type
with which Webb would have been thoroughly and completely disgusted.)

As for the consensus of the Workshop, Duncan Steel pointed out that of the
12 professionals directly involved in the astronomical search for the next
Earth impactor, none of them was in attendance at the Workshop, though later
Grant Stokes, of the Department of Defenses' LINEAR program, did appear
briefly on Thursday. Instead, those from the US who attended the Workshop
were those involved in the efforts to determine the properties of asteroids
and comets, those whose programs Weiler has always asserted are NASA's
responsibility, and those whose programs he has always funded, and those who
programs Weiler pledged to continue funding in the plan which Belton put
forward. Thus going into the Workshop Weiler could be fairly sure of
obtaining those scientists' approval for his plan.

Before I left on Thursday, I noted this discrepancy in accounts to several
Workshop attendees, and by Saturday, a press release was sent out
identifying Eric Asphaug as the Workshop's organizer. This makes yet a third
account of how the Workshop came into being. Eric's involvement in the
Workshop may probably best be viewed as an attempt to give a "scientific
validity" to the policy decisions which had already made by the various
bureaucrats, those policy decisions which again were sprung on the
Workshop's participants late on Thursday afternoon. It is certain that the
good science which was presented at the Workshop, and there was a great deal
of it, of which more shortly, was entirely Eric's fault. My hat's off to
him.  But I digress...

CONGRESSIONAL ACTION IN 2003

I suppose this is as good a time as any to mention that the members of the
Congress are waiting for a report on the impact hazard from a Federal agency
separate from NASA, the results of which are to be to delivered in 2003, and
that they will then take action on the basis of that report. That the
legislators went to a Federal agency separate from NASA to obtain this
estimate of the impact hazard is a clear sign of their lack of trust in NASA
management in dealing with what they view as a very real threat to their
constituents. From what I've seen of NASA's actions so far, they made this
judgement on a very sound basis.

My hope is that efforts of NASA management to promote arbitrarily low
figures for the impact hazard via efforts such as the manipulation of this
Workshop will ultimately be futile. About the only thing which NASA
management could do at this time to contribute to the effort of accurately
determining the impact hazard would be to conduct accurate crater counts on
the new Mars imagery: unlike the Moon, the planet Mars has no nearby large
gravitational companions. Such a crater count is the only thing which will
measure both the hazard presented by asteroids as well as the hazard
presented by comets. To my knowledge, NASA has so far avoided every
opportunity to perform these new crater counts.

For my own current estimate of the impact threat, derived from the
historical, archaeological, dendrochronology, and climatic record, see the
Appendix below. This is only an interim estimate, and it will be improved as
new results come in: additional impact events will probably show up in the
data from India, Africa, the South Pacific, northern North America, and
China.

In response to a question about his responsibility to address the public's
concerns about their safety from impact, Weiler said that if an extinction
level event took place which killed everyone, he would not mind taking
questions afterwards. From this one can easily deduce that Ed is a rather
complete atheist, as otherwise he could reasonably expect to spend all of
eternity being questioned in a legislative hearing. On the other hand, it may just
feel like all eternity.

HOW TO DEAL WITH THE IMPACT HAZARD: THE COMET AND ASTEROID PROTECTION SYSTEM

In one of those accidents of omission, Dr. Mazanek of NASA's Langley
Research Center was actually allowed to present the results of his analysis
of how to deal with the problem in a poster set in the far corner of the
poster room.  His study may be viewed online at:
http://rasc.larc.nasa.gov/rasc_new/CAPS/CAPS_Concept_Summary.pdf

or
http://www.space.com/businesstechnology/technology/lunar_caps_011212-1.html

In sum, Mazanek's system uses a large telescope complex built on the Moon
for the detection at long range of large objects, and it uses a Moon based
Lidar for the detection of smaller objects (100 - 200 m) passing near the
Earth. While some Conference participants may think such a system a fantasy,
let me assure them that it is indeed possible for men to go to and work on
the Moon.  Over the years I have actually met several of them, and while
they are far more intelligent than most of us, I can confidently assert that
they do indeed put their pants on the same way we do, one leg at a time,
even though I have not verified this by personal observation.

The most likely reason that Mazanek's engineering study was allowed to slip
through the NASA bureaucracy in the first place was that he advocated that
this system be built only around 2035, well after their much desired manned
flight to Mars had taken place. In his study Mazanek also advocated the use
of what he calls HPFM modules, re-usable fuel modules which use a
combination of high efficiency low thrust engines and low efficiency high
thrust engines to accomplish the construction, and the development of these
would take some time.

For a different architecture for the construction of lunar facilities, one
using existing technologies, and which I set out several years ago, see:
http://www.geocities.com/epgrondine
For earlier US lunar architectures see Mark Wade's work:
http://www.astronautix.com/
and for earlier Soviet lunar architectures see: http://www.astronautix.com/

(It is interesting to note that the Chinese release of information on their
manned efforts to roughly 1969 now means that they have begun work toward
meeting one of the prerequisites for international cooperation in manned
space flight. Both the astronauts and the cosmonauts take a particular
interest in the fate of astronaut trainees and their families.)

The slowdown in the communications markets means that commercial launchers
will be available for the construction of such a lunar NEO telescope;
additionally, as the construction of the International Space Station will be
completed around 2006, at that time the US and other countries will have
available the engineering personnel and the manufacturing facilities
necessary for its construction.

For diverting threatening asteroids and comets, Mazanek advocated the use of
nuclear electric engines to get quickly to the threatening comet or
asteroid. After the spacecraft arrived at the asteroid or comet, its
propulsion system's nuclear electric generators would then be used for
ablative laser propulsion: in other words, by vaporizing its surface with a
laser and thus diverting the threatening object through by a jet reaction
fueled by its own mass. Little risk of fragmentation into smaller still
hazardous pieces arises with the use of such technology.

I think that every reporter's questions to either Ed Weiler or Colleen
Hartman as to why NASA has such a sudden need to visit Pluto or any of the
outer bodies, and to develop nuclear electric power generators to do this,
has met with vague and unsatisfying answers.  Since about 70% of the US
public thinks that Pluto, Mars and all the nebular clusters in M27 are all
real pretty and all that, but fundamentally not really worth a sh*t, and
would prefer that NASA use their money to find the next chunk of space stuff
before it hits and kills a lot of people (this is actually an informal
paraphrase of repeated poll comments), my thinking is that Ed and Colleen
could save themselves a lot of grief if they simply stated that the nuclear
electric powered propulsion systems were being developed for exactly the
purpose of stopping the next one of these comets or asteroids before is
hits.

After all, honesty is so important when discussing matters of public policy.
The power of Mazanek's system's lunar telescope ensures that if diversion by
laser ablative propulsion fails, there will enough time left for a second
attempt using nuclear charges to effect either diversion or destruction.
That's 2 shots, and no other system even comes close.

WHY USE NUCLEAR ELECTRIC POWERED LASER ABLATION PROPULSION FOR DIVERSION?

Rick Binzel presented a summary of what is currently known about the
properties of all asteroids, including the threatening ones.  Generally, the
percentage of each type of asteroid matches well spectrally with the
differing percentages of the types of meteorites recovered on Earth:

ASTEROID TYPE        METEORITE TYPE           PERCENTAGE

Iron:
M-Type               Iron                     4%

Stoney Iron:
A-Type               Stoney Iron              1%

Stones:                                      95%
Achondrite:                                   9%
Vesta-type           Basaltic Achondrite      9%
Chondrite:                                   86%
S-Types              Ordinary Chondrite      81%, when spectra adjusted for space weathering
G-Type               Carbonaceous Chondrite   5%  usually assumed to be dead comet fragments

These data indicate that the mechanism for the ejection of meteorites works
uniformly across all classes of meteorites.

The problem that emerges is that the measured densities of the meteorites
are far greater than the estimated densities for the asteroids, and this low
porousity and crushability of the asteroids generates problems for most
means of stopping them from hitting. The same problems appear to hold true
for the means of handling in-bound comets as well.

ESTIMATING THE DENSITIES AND POROUSITIES OF ASTEROIDS

Generally, the volume of any asteroid is estimated by the formula
log(asteroid diameter) = .8*log(asteroid reflectivity) + 3.13 -.2*(adjusted
optical magnitude)

The key here is the asteroid's reflectivity, and estimates of these vary by
200-300%. Work is being done to refine the estimates of reflectivity for
each class of asteroid; one initial result of this work on reflectivity is
that the smaller and faster rotating objects in each class of asteroid
appear brighter, and this difference in reflectivity is most likely due to
the darkening over time through space weathering of the larger and older
asteroids.

Duncan Steel stated to me that infra-red astrometry, and comparison of the
infra-red (retained light) signatures with visible light (reflected light)
signatures would enable the absolute determination of asteroid volumes and
thus their densities. In this he is undoubtedly correct; while the UK has
facilities at which this work could be done, this work is not funded. Also,
the use of European Southern Observatory facilities for the gathering of
asteroid light curve variations and their spectra has been denied. My
thinking is that European asteroid astronomers should now launch as many
proposals towards the ESO controlling body as they possibly can, and be as
vocal as possible when those proposals are turned down.

In the meantime, the sizes of the different types of asteroids are being
estimated by the method given above, and the shapes of the rotating
asteroids are being extracted from variations in their light signatures.
There were repeated mentions to me by other astronomers of their desire for
the source code for this software, software which extracts some 8 shape
components from the single plot of the variation in the light reflected by a
rotating asteroid. I am not aware of the degree of public funding of this
software, its ownership, or if it has any defense or industrial use.

The results of the analysis of the optical data are being closely compared
with both the results of radar imaging, which is being conducted by Steven
Ostro and his colleagues, (including prominently among them the software
developer Scott Hudson), as well as with the data which had earlier been
returned by the spacecraft which have visited several of the asteroids.  New
data important for the resolution of these problems in asteroid density and
surface weathering will also be returned shortly by the Japanese Muses-C
spacecraft, and similar data for comets will be returned by the United
States' Deep Impact probe.

The bottom line is that currently the meteorites appear to be much denser
than their related asteroids. This estimate is also in agreement with the
analysis of bollides and asteroids which has been done by the European
Fireball Network, the results of which Mario Di Martino of the Observatorio
Astronomico di Torino presented to the Workshop.

Thus the asteroids currently appear to be rubble piles with space weathered
surfaces, some of them so crushable that they flow into bar-bell shapes due
to the effects of their rotation.

EFFECT OF INTERIOR CRUSHABILITY AND SURFACE POROUSITY ON THE TECHNIQUES FOR
MITIGATION

Keith Holsapple of the University of Washington presented some initial
mechanical calculations of the effects of these new estimates of
crushability and porousity on several of the techniques which had been
advocated for "mitigating" the hazard presented by a threatening asteroid.
These restraints would appear to apply to stopping comets as well. All of the
estimates which Holsapple presented publicly are of limited use, as he could
make no use of the research results of the laboratories of the United
States' Department of Defense or Department of Energy. These limitations
have key consequences.

First off, the efficiency of diversion by simple mechanical impact fell from
13 X the energy of impact to .2 X the energy of impact. Earlier estimates
had been that a 200 to 1500 ton mass moving at 10 kilometers per second
would be necessary for diversion; Holsapple's new estimate was that
diversion by simple impact would require a 15,000 ton mass to accomplish the
same job.  Clearly this would not work, unless the total asteroid population
was so accurately mapped that a "billiard ball combination shot" type method
could be used to move a small asteroid into the path of the larger
threatening one.

For mitigation by explosive destruction, the old estimates were that a 90
kiloton nuclear charge would be needed; Holsapple's new estimate was that
1,000 kilotons (1 megaton) would be necessary.  As my rolodex currently has
contact information for individuals able to construct nuclear charges up to
100 megatons gross, explosive destruction would still appear to be a viable
method of mitigation.

For impactor diversion by stand off nuclear explosion, the old estimate was
that a charge of between 100 kilotons to 1 megaton would be necessary for a
1 cm/sec change in velocity; the new estimate was that identical charges
would result in no more than a 1 X (10^-3) cm/sec change.  I checked with
Holsapple after his presentation, and he had made no account in his initial
estimate for a release of energy through a dissociation of matter into
plasma by the use of ringed nuclear charges detonated simultaneously.

As for diversion by painting an impactor and thus changing it's light
gathering efficiency, under the space weathered rubble pile model this
technique would effect only the potential impactor's surface. No joy.

The effects of ablation by laser, e-beam, and x-ray on these weathered
rubble piles were unknown to Holsapple. As I mentioned before, both
Department of Defense and Department of Energy laboratories have done
extensive work in this area. Holsapple called for experimentation in open
and public laboratories. Dr. Mazanek's estimate is that a high power laser
could be used to vaporize a potential impactor's surface, and that the
resulting reaction force would be sufficient to divert it into a
non-threatening path. Since even the smallest nuclear electric powered
lasers could be fired indefinitely, in banks if necessary, I think he's
right.

In Holsapple's initial estimate, the techniques which he allowed as feasable
for mitigation were the use of mass drivers, solar sails, or propulsion.
Once again, Dr. Mazanek's estimate is that nuclear electric powered laser
ablation propulsion is the preferred method of altering a potential
impactor's course. In as much as nuclear electric powered laser ablation
does not require the transfer of the mass of the fuel for the jet reaction
to the impactor, but instead uses the impactor's own mass for fuel, it is
clearly several orders of magnitude more efficient as a method of diversion.

"THAT DEPENDS ON HOW YOU DEFINE SEX"

During one question period, I asked Ed Weiler whether he personally
preferred the proposal for a lunar telescope or a manned flight to Mars as
the successor project to the International Space Station. He replied that
NASA had no proposals for either, using the strict NASA contracting sense of
the word "proposal". I understand that some of today's youth have followed a
former executive's example, and have actually managed to convince their
girlfriends that oral sex is not sex. D*mn, why didn't we think of that when
we were younger?

Dr. Weiler next stated that no decision had been made on either, but that he
agreed with the current NASA Administrator Sean O'Keefe that whatever
project would be proposed would have to be justified by "SCIENCE" (emphasis
indicated), as if the unrealistic impact hazard estimate which was foisted
on the Workshop late Thursday afternoon had any validity, and was the only
one justified by "SCIENCE" as he wanted to try to define it. (Again, for another
impact hazard estimate, based on the observed record, see Appendix below).

However great or small the impact hazard ultimately turns out to be, from
Weiler's statement it is clear the goal of addressing the public's need to
be assured of their own and their families' safety and security plays little
role in his thinking. Understating the hazard simply allows him to reduce
its impact upon his previous plans.

In closing his answer, Weiler stated that if space based assets were
necessary, he would prefer the use of telescopes in free space to the use of
those on the "dirty old Moon". While this is only the second best option,
clearly, as I have argued for some time, and was demonstrated by Weiler's
actions here, in the US insisting on a lunar based telescope leads to
advancement of concepts for using space based telescopes to deal with the
impact hazard. As most here know, space based telescopes are the only things
which have any hope of dealing with the Tunguska size impactors of 50-100 meters
or so diameter, or of giving the earliest possible warning of in-bound comets.

Viewing the results of questioning the manned Mars program by advocating a
lunar based telescope, I am confident that threatening the Next Generation
Space Telescope, (even after its contract has been let), could lead to at
least a NESS class telescope being placed in orbit in the very near future.
My suggestion is that some NEO astronomer out there should try it; while the
use of this technique will not make you many friends along the way, at the same time you
will have the satisfaction of knowing that you have done your part to ensure
many peoples' lives and welfare. 

I am looking forward to Dr. Weiler's detailed comments on Mazanek's
comparison of the problems of electro-static dust containment on the Moon
with the problems arising from the computation, data transmission, electric
power, and pointing accuracy difficulties of free space based assets. I
expect that he will be presenting his detailed analysis no later than
sometime in mid-2003, about the time of the Congressional decision.

HOW TO NOT DEAL WITH THE HAZARD PRESENTED BY EARTH IMPACTING COMETS

As a follow-up question to one of Weiler's answers in which he mentioned the
1 kilometer diameter NEO goal, I asked whether that goal included both
asteroids and comets. Weiler replied that the entire US economy did not
generate enough money to map all the comets in the Kuiper Belt. By this
answer Weiler clearly hopes to avoid the issue of providing the earliest
possible warning of Earth impacting comets, which in the recent past have
produced about half of all impacts, and as Steel pointed out privately, are
also implicated in nearly all of the Extinction Level Events (dinosaur
killers).

While one could hope that the historical data (see Appendix) represents a
recent spike in comet impact activity, and that this particular danger has
passed, the recent appearance of Comet Shoemaker-Levy 9, and the impacts
into Jupiter of its fragments, and the resulting Earth-sized explosive
plumes, may indicate that we are by no means assured that this process of
comet injection into our Solar System is over. At this point in time, we
simply do not know - and hence the need to err on the side of caution. Even if all
the recent Earth impacts which may have been due to fragments of Comet Encke
are removed from the historical record, enough danger remains to suggest an
extreme course of action.

THE NSF'S WAYNE VAN CITTERS VIEWS

What we have been seeing in the recent past are the reactions of every
government in the world in dealing with a problem they never knew they had,
and the resulting disputes between the different organizations within those
governments over their roles and responsibilities. The earlier disputes
between NASA and the NSF over their responsibilities I reported on at:
http://abob.libs.uga.edu/bobk/ccc/ce021102.html

Since my initial reports, co-ordination between NASA and the NSF has been
moved to a formal level by Congressional mandate. While it is intended that
this process will insure co-ordination and eliminate duplication in the
observing programs, it is significant that no agreements between the two
organizations have been reached yet. In the NEO area, this particularly
currently includes agreement regarding the operation of the Areceibo radar
astronomy antenna in Puerto Rico, the operation of which is important to
those studies which are attempting to better define asteroid densities.
Steve Ostro spoke repeatedly about his team's frustration in getting
observing time on any of the radar antennas.

While van Citters made mention of a Giant Segmented Mirror Telescope,
primary discussion focused on the Large Scale Synthetic Aperture Telescope,
or LSST. While no site for the construction of this telescope has been
selected yet, its construction is expected to begin in 2006-2007, at a cost
estimated at some $170,000,000. Also, while it is anticipated that 50% of
the observing time on the LSST will be devoted to NEO detection, allowing a
survey of the entire sky to magnitude 24, or to Near Earth Asteroids of some
300 meters diameter, the NSF and NASA have not come to any agreement on the
division of the LSST's operating costs. I do not know how effective the LSST
would be at detecting the appearance of new Earth bound comets, or how much
time it could provide for taking action to deal with them. Steel's estimate
was that the astrophysicists would quickly gain control of the LSST and
reduce the time available for NEO detection to the lowest level they could
get away with.

Special note should be made of the inquiry by an ISAS (Japanese Space
Agency's) representative about the possibility that the US would be open to
international cooperation in LSST, i.l. Japanese participation. Wayne van
Citters stated that if a formal proposal was submitted, a response would be
made.

The physical restriction of the LSST to a 300 meter level (no range given)
of detection is important. Weiler's current proposal (sprung on the Workshop
late Thursday afternoon by Mike Belton) is that over the next 25 years the
NSF would construct the LSST (Large Scale Synthetic Aperture Telescope),
while the Airforce and the University of Hawaii would construct the PanSTARS
telescope, and that these telescopes along with those involved in the
current NASA Spaceguard effort will be sufficient for NEO detection for the
next 25 years.

By restricting the NEO search to the use of ground based telescopes, and
avoiding the use of space based assets, Weiler clearly hopes to avoid making
NEO detection a NASA responsibility, or as he has put it repeatedly, "Who
nominated NASA to be in charge of saving the planet?". Since both the
reliable detection of the smaller Near Earth Asteroids, ones of 100 meters
or so diameter, in other words those capable of producing Tunguska class explosions,
as well as the earliest possible warning of approaching comets both require the use of
space based telescopes, I asked  van Citters if the use of space based
telescopes was solely NASA's responsibility. Wayne stated that it absolutely
was. The NSF's position on this matter seems to me to be both well formed,
and in line with US legislators' expectations.

Weiler has always stated that he would take the NEO detection job if given a
both clear legal mandate and the funds to do it. The problem has always been
that Weiler will not face up to the hazard and give the legislators a clear
statement of what he would require to handle it, as they in turn would most
likely divert that money from the research programs which benefit Weiler's
existing clients.

NEOs AND THE MEDIA: FORGET THE TORINO SCALE AND THE PALERMO SCALE, HERE'S
THE DC SCALE

At the session on the media and the hazard, Morrison expressed amazement
that the public actually expected NASA to already know where all the
dinosaur killer class NEOs were, and that they were shaken when some of
these asteroids were found only after they had passed between the Earth and
the Moon. I brought up the fact that while the public is entertained by Mars and
all the astrophysics of far away stars, they would prefer that their money be spent
on something of more immediate concern to them, like finding the next chunk
of stuff before it hits the Earth and kills large numbers of people.

I also tried to explain that the purpose of a journalist is to sell papers,
and that as long as the officials' performance failed to satisfy the public,
journalists would be able to feed on their pride, or on their bosses pride -
from the looks of things, it's going to be good eating.

My own favorite piece of journalism is the following by Andrew Parker of The
Sun (London) 25 July 2002, written by him during the 2002 NT7 flap:

"A teenager who could die on his 33rd birthday if the asteroid hits Earth vowed
last night to bed as many girls as he can by then. Paul Tonks, 16,
said he aimed to travel the world between now and February 1, 2019.
The lad, from Birmingham, is due to start his A-levels in September and
has not had a serious girlfriend yet.

"But he said: "I've always been a bit careful. Now I'm going to
enjoy myself. I'm going to start smoking, drink as much as I can, and
sleep with as many girls as will let me."

"I haven't had many girlsfriends but that's going to change." He
added: "It's not fair that the asteroid would have to hit on my
birthday. I've only had 16. "I'm certainly going to make the best of the
next 16."

No need to ask any scientists or bureaucrats any questions for your piece,
no need for any technical writing, no need for any travel, but just simply
talk with the kid next door, write it up, and walk away with a fat pocket.
I'd  have bought that paper, and I am sure that many did.  Simply Great Work
- a classic, and there ought to be a prize thrown in as well.

The consensus among some of the presenters seemed to be that if they just
improved the wording of the Torino Scale or the Palermo Scale, the public's
frustration with them for their inability to assure them of their safety
from this hazard, which surfaces during the flaps, would simply disappear.
They don't understand that the concern which arises during the time it takes to
refine the orbit of a potentially threatening impactor to one of no threat
reflects more generally the public's lack of satisfaction with the extremely
limited efforts which the governments are now undertaking. Journalists are
guaranteed both easy copy and good sales as long as officials continue to
try to justify the paltry amounts they are spending on dealing with this
hazard, while at the same time they waste plenty of the taxpayer's money on
metric tons of other space nonsense.

I don't know what its going to take to get through, but I present here to
irritated space bureaucrats everywhere The DC Scale, a way of measuring the
public's concerns about the NEO hazard, along with some of the courses of
action open to you, if you have no intention of actually doing anything
about it:

THE DC SCALE

0 - Public oblivious to the danger: no need to do anything
.5 - Public aware of local ancient small impact as a curiousity: no
need to do anything
1 - Small upper atmosphere detonations affect early warning systems,
but public does not know about it: no need to do anything, as the
military will take action to ensure that accidental nuclear exchange
does not take place
2 - Public aware of Tunguska impact as a curiousity: no need to do
anything
3 - Public growing aware that dinosaurs were killed by impact:
proposals for detection systems can be bandied about
4 - Knowledge of hazard presented by smaller impactors starts to
spread to public: no need to do anything, but expect very unusual to
absolutely bizarre behavior by the few members of the public aware of
the problem; best to label them as cranks.
5 - Public aware of dinosaur killer and see 2 movies concerning
impact: no need to increase funding, but time to organize existing
ineffectual efforts into larger ineffectual program.  Promise to find all
dinosaur killers by sometime in the indefinite future.
6 - Upper atmosphere detonations continue, military takes more
detection steps: take credit for these.
7 - Public becomes aware that not all dinosaur killers have been
found, and you won't be doing it any time soon: Journalists are able
to sell newspaper articles to concerned public; and you will face
mild questioning by your legislators. BS them.
8 - Legislators become aware of multiple Extinction Level Events and
small impact hazard
9 - Legislators become certain of multiple Extinction Level Events and
multiple small impacts: Legislators will stop relying on your opinion, but
will not fire you quite yet. There's still time to cloud the data
regarding multiple extinctions and small impacts and to label those
working in the field as cranks.
10 - Public and Legislators concerned when upper atmosphere detonation
occurs which nearly triggers nuclear war: Shared Impact Alert system set
up by military. Try to gain credit for this.
11 - Public becomes aware of multiple extinctions and small impact
hazard: Time to arrange personal finances in case of job loss.
12 - Intense questioning by Legislators about your performance in
dealing with impact hazard: Time to quickly resign so as to not affect
future job search.
13 - Public satisfied with government performance in dealing with the
NEO hazard: Time to criticize your successor for spending too much money
on a non-existent problem.

It took nearly 10 years, from roughly 1980 to 1990, for the Alvarez's
observation that the dinosaurs were killed by an impact to gain general
acceptance, and the sensational story today in 2002 is the one where someone
claims that impact did not kill the dinosaurs. It took another another 8
years after 1990 and two movies (1998) to see the beginnings of any
organized detection effort at all. The time needed for the spread of the
knowledge of the small impact danger is comparable, and while we're at Level
10 about now, we should be at Level 12 in 2003, and at Level 13 by about
2004-2005.

I don't know where you in the UK stand in this process: at one session Steel
rather accurately described one of Lord Sainsbury's recent comments
"b*ll*cks". Among the many interesting things which I learned during diner
on Wednesday is that the efforts in both Italy and France are being driven
by the scientists, instead of by public concern. If I had to make some
guesses on why there is more action in the US, I think one must remember the early
work of Shoemaker, first at Barringer Crater, which lies in the US, and which has been
a major tourist attraction for decades; the support of Shoemaker's work first by the
Department of Defense, then by NASA, and always by the United States
Geological Survey; and finally Shoemaker's work with Representative George
Brown. For the UK, the process would seem to have started with Clube and
Napier's work; continued with the SIS, then CCNet and Spaceguard UK; and
then been moved to the legislative level by Lembit Opik.

A final interesting item to note is that the working language of the
Cambridge Conference is English, and that some 200 science writers receive
it. The bulk of the articles which we receive are in English, and this
probably represents rather accurately the levels of public concern within
each country with the hazard - usually this technique of estimating public
sentiment is known as a "count of column inches". Perhaps one way to move
the process along in Europe would be to see that Clube and Napier's works
were translated into French, Italian, and German; another might be for a
French, Italian, or German Conference participant to use one of the online
machine translators to translate the Correspondence as it appears, and then
to forward the translations on to the science writers who use those
languages. It is far easier to work in your own native language,
particularly when faced with stacks of technical material. The same might by
done to produce translations of the Conference archives. I don't know have
any suggestions as to how to handle the Russian or Chinese translations.

THE AIR FORCE'S PETE WORDEN

Due to traffic I was unable to catch anything but the last minutes of Pete
Worden's presentation.  In addition to his paper, Worden spoke briefly about
the problems he has encountered in moving the NEO issue through the
bureaucracy, and this was a very amusing tale indeed. After his presentation
I told Pete of the problems which I had had with the traffic, and asked him
if he would be sending his entire paper along to Conference participants,
and he said that he would. I think that Conference participants would also
enjoy hearing his account of his battles with the bureaucracy - I know I
would be most interested in hearing the story right from the start, with his
early work with Dr. Teller on this problem.

I also asked Worden about the effort toward a shared after the fact
notification of the smaller impacts to the launch officers of other
countries, and he told me that putting this system in place this was well
underway - lest I misquote him on how far along this effort has proceeded, I
will wait for his own account to Conference participants. Here is yet
another area where Dr. Mazanek's system would have great benefit, as he
advocates the use of a Lidar based on our Moon for the earliest possible detection
of the smaller impactors: with Mazanek's system one would be able to contact the
launch officers well BEFORE one of the smaller ones hits, instead of having to try to work
through the confusion to notify them AFTER it has already hit. The event of
6 June during the height of Pakistan-India tensions shows the need for as
early a warning as possible.

Before he had to leave the Workshop, Pete gave me a copy of his paper, and I
will mention some of its highlights here. As an operating officer, what
Worden encounters most often are the very smallest of impactors, those which
detonate in the upper atmosphere some 30 times per year.  Thus he is highly
aware of the problem in its full scope. For the ground based search, Worden
advocates a set of 3 meter telescopes equipped with new large format charge
coupled devices, two telescopes capable of scanning the entire sky every few weeks.
He thinks that this would help with the problem of dealing with the small objects, but
my thinking is that Mazanek's Moon based Lidar would be far superior for this.

For space, he would first like to have the Canadian NESS package launched to
provide near sun coverage. He would also like the next generation of
military space surveillance satellites (not the Earth surveillance
satellites, but the ones which examine objects in space) equipped so that
they are able to handle the NEO detection role as well.

One problem that he is likely to encounter is with his proposal for a
Natural Impact Warning Clearing House, which would be under US Department of
Defense control. Worden quite rightly views small and Tunguska class impacts
as being so frequent that ways of handling data on them will have to be
handled on an operational basis, and that the US Department of Defense will
have to have its own center and personnel for this. But I do not think that
the international community will trust such a vital function entirely to the
US. In my view, that's one of the reasons why the Smithsonian Minor Planet
Center data clearing house is of such great importance: it already has
international acceptance.

As an initial step towards mitigation, Pete would like to have expensive
($10,000,000 or so) micro-satellites sent to the smallest objects to obtain
data on them, as these are the ones which are most likely to hit. For the
diversion of these small objects (100 meters or so diameter) he viewed
diversion by simple mechanical impact as the most feasable technology,
rather than the use of nuclear charges.

For all objects, including the largest ones, Worden's opinion is that
mitigation would be accomplished most effectively by one country. Again,
while he is quite right in this, it is not likely that other countries will
trust solely the US to perform this duty. Russian plans for dealing with the
NEO hazard have already been circulated to Conference participants, and the
Russians expressed their reservations and concerns very clearly in this
study. The Russian scientist who was to have presented at the Workshop
cancelled; most likely this was due to budget pressures, rather than for any other reason.

Worden also advocated that the US Department of Defense undertake a study
gathering all data and assessing the impact threat. He was not aware that
such a study by another Federal agency was already well underway, and that
it is due to report to the Congress in 2003.

CURRENT AIR FORCE WORK ON THE NEO DETECTION PROBLEM

Since I missed this very important presentation, I will include its abstract
here:

A SPACE-BASED VISIBLE/INFRARED SYSTEM FOR THE CHARACTERIZATION AND DETECTION
OF NEOS
M.P. Egan (AFRL/XP), Y.J. King, P.D. LeVan, B.J. Tomlinson, & B. Flake
(AFRL/VSSS), & S.D. Price (AFRL/VSB, VSS)

"We present the technical capability for a modest sized (third to half
meter) space-based visible/infrared instrument to accurately determine the
diameters of NEOs and to augment their discovery by extending the survey
beyond the limitations of ground-based instruments. Previous analysis [has]
demonstrated the measurement capabilities for accurate size determinations
(Price and Egan, 2001) [as well as] the detection/discovery efficiencies of
such a system for objects [of] 200 meter[s] in diameter and larger (Tedesco
et al., 2000). The Air Force Research Laboratory's research program in
developing spacecraft/sensor technology in the critical areas of focal plane
arrays, cryocoolers, on-board signal processing, and integrated spacecraft
structures is key to being able to field a light-weight, cost effective
satellite.  Mid-Infrared focal plane arrays are being developed for space
observation applications. The mature Si[licon]:A[r]s[enide] F[ocal] P[lane]
A[rray] technology will be described, as will be other innovative
technologies for both the infrared and visible wavelength regions. Current
candidates for low background, Mid-Infrared applications require cooling to
almost 10 [degrees] Kelvin. Active low temperature cryogenic cooling for
Mid-Infrared sensing applications is being addressed within the Space
Vehicles Directorate of the Air Force Research Laboratory (Davis et al.
2001, Tomlinson et al. 2001) to address mid to long term D[epartment] o[f]
D[efense] mission requirements. Ten [degree] Kelvin cooling technology will
soon reach proto-flight capability, provid[ing] tremendous savings in
payload mass [compared  with those of] stored cryogen systems, and greatly
increases the payload performance (with increased cooling load capability)
and [the] lifetime: 10 years and longer. Trade studies will be shown that
evaluate the performance versus maturity levels of the subsystem
technologies."

The important point here is size and range of the potential impactors which
may be able to be detected by the proposed satellites. These satellites'
abilities may be good, but undoubtedly they are far less than a Moon based
Lidar system.  On the other hand, these satellites are far more likely to
actually be built.

NASA FIRMLY PLANS TO LET THE NEXT ONE HIT, AND YOUR CORRESPONDENT LOOSES IT

As I mentioned earlier, Tuesday morning I had received the abstracts which
contained Morrison's entirely misleading estimate of the impact hazard, an
estimate which sets the occurrence rate of Tunguska class impact events at 1
per 1,000 years; the observed rate (Appendix) has to be somewhere around 1
per 100 years. The only question left was how this new view was going to be
given the guise of scientific respectability by the Workshop. The answer
came with Belton's presentation on Thursday afternoon.

When Belton first used a low number, of only 1 impact of 80 meters per 464
years, I interrupted and told him that I was intimately familiar with the
observed impact rate and that it was roughly 1 Tunguska class impact every
100 years and 1 mega-tsunami every 1,000.

Though Steel told me afterwards that "Ted's book has been getting bad
reviews.", I don't think that the reviews are quite bad enough to alter
Bryant's work by much, given that Bryant is a highly skilled geologist who
specializes in the area of tsunami. The rate of planetary accretion for the
Earth was estimated at 24,000 metric tons per 100 years by Mario DiMartino
of the Observatorio Torino, with 80% of this in the 10 to 100 meter diameter
range, and 20% of it being larger than 100 meters in diameter, numbers which
agree very well with the observed historical record. In other words, 4,800 metric
tons per 100 years, in pieces larger than 100 meters in diameter.  I don't know
how the comet fragments fit into this number.

Belton continued with his presentation, but he was shook, and interrupted
himself a few minutes later to mumble that of course Morrison and Weiler's
hazard estimate was in agreement with my own, and that my estimate could be
generated from Morrison and Weiler's by simple Poisson probabilities.

Belton continued with his presentation of Weiler's plan, which anticipated
that NASA's role would be limited to that pretty much already existing:
detection programs were to be limited to ground based telescopes run
primarily by the National Science Foundation and the Department of Defense,
with NASA's Spaceguard telescopes playing a limited role, while during the
same period NASA would launch probes to determine the properties of
asteroids and comets. This continuation of the current state of affairs was
to run for some 25 years. To show how firmly entrenched this plan is
entrenched in Weiler's thinking, the Workshop's own cost of some $100,000
was included in the plan's total cost.

The plan was envisioned to run to 2027, at a cost of some $3,279,000,000,
with initial research on mitigation technologies beginning some 10 years
out, in 2012, and the development of actual mitigation systems to only start
in earnest after that, at which point the Workshop let out a collective
groan. Weiler/Belton estimated that following 2027 the Air Force effort at
actual mitigation would then take an additional $1,500,000,000 and run for some 15
years, finally providing a reliable system in roughly the year 2042 at a
cost of some $4,779,000,000 in 2002 dollars.

>From Belton's plan, it was clear that Weiler had gone with Holsapple's
initial estimates, and that the techniques which he allowed as feasable for
mitigation were the use of mass drivers, solar sails, or propulsion.
Weiler's lack of interest in diversion by ablative laser propulsion is
interesting, given NASA's current investments in electric generation in
space by the use of nuclear reactors.

With the use of solely ground based assets, instead of space based ones,
there is somewhere around a 1 in 4 chance that the Earth will be hit
unawares by a Tungunska class impactor over the next 25 years, and around a
1 in 2 chance that it will be hit unaware by 2047. I interrupted Belton,
accusing NASA of doing nothing to deal with the most likely immediate real
threat from objects between 100 meters to 300 meters. Belton denied that the
government was doing nothing, and declared: "Look, I've been so concerned
about this problem that 6 years ago I changed my job. When Ed (Weiler) was
contacted by several Congessmen on this, and he asked for my help."

As Belton's presentation showed, Weiler and Morrison's plan to deal with the
small impact hazard is simply to try to pick up the pieces after the next
small one hits. In point of fact they budgeted some $20,000,000 for what
they called "Ameliorization", as though this amount has any connection with
the actual damages which will be caused by the next Tunguska size impact or
mega-tsunami caused by impact, or could do much to help "ameliorate" those
damages. They saw an identification of "Ameliorization" needs beginning in
2003, with training beginning in 2006. 

THE GOOD PART OF WEILER'S PLAN

A journalist is expected to be unbiased, so let's see if there's anything
good I can say about Weiler's plan. There is.

His list of both the knowledge needed and the technologies needed to deal
with this hazard were excellent. Weiler sees 4 medium class missions between
now and 2027, with starts every other proposal cycle. Undoubtedly these
missions will use nuclear electric propulsion and will develop the guidance
and control systems necessary for diverting one of these things. The numbers
given in the presentation were fuzzy, ranging anywhere from $350,000,000 to
$600,000,000 per mission, but since the opportunity cost, the cost of the
impact risk, is some $2,600,000,000 per year, these missions should be
do-able.

RESULTS OF THE WORKSHOP

Well, Benny, the truth of it is, I just don't know what they were. I left
Thursday evening and did not return for the "discussion" of Weiler's plan
which took place Friday morning.  Considering that the Congress will take
action based on their own independent assessment of the hazard due in 2003,
I didn't see much point. In this regard it is important to note that
Jonathan W. Campbell of NASA's Marshall Space Flight Center endorsed
Mazanek's proposal to use laser ablative propulsion for diversion. The way I
count it, that's Langley and Marshall: if Johnson gets onboard, Headquarters
OSS and Ames will have a rough time stopping them.

The true science which was done at the Workshop was great, and my thanks to
Eric Asphaug for organizing its presentation here. Steel is going to be
overseeing publication of the Workshop's proceedings for Cambridge
University Press; while some of the abstracts have already been circulated
to Conference participants, my hope is that more of them will be along
shortly. My apologies to several of the astronomy and spacecraft teams whose
presentations I missed, in particular that of Andrew Cheng of the NEAR team on asteroid
composition; that of William Bottke (SwRI), Alessandro Morbidelli (Obs. Nice) and Robert
Jedicke (U. Arizona) on asteroid population estimates (which does not
include any estimate of the impact hazard due to comets); and G.B.
Valsecchi's presentation of his and Carusi's work on using a small
deflection to steer a threatening object towards some large body with a
large gravitational field - a very good idea.

PERSONAL IMPACT "AMELIORATION" STRATEGIES

The Workshop ended with no relief in sight for Marsden and his 1.5
colleagues at the Minor Planet Center, who are still putting in 80 hour
weeks, as they have been doing through all the weeks and months of the last
couple of years now. My condolences to them and their families and friends.

Since one of the "Workshop on Scientific Requirements for Mitigation of
Hazardous Comets and Asteroids" organizers' main goals was to make it clear
to everyone that mitigating an impactor is "Certainly not our job", as
NASA's Colleen Hartman put it, what follows are some suggested strategies
for personal "amelioration", to use Morrison's term.

TUNGUSKA CLASS IMPACT OCCURS IN ANOTHER COUNTRY: Decide to take comp time
and make it an early day. When stock trading re-opens, short the stock of
any company which does business with or in that country. Remove affected
country from your list of possible vacation spots.

MEGA-TSUNAMI HITS ANOTHER COUNTRY: Same as above, except leave work
immediately, and do not stop to fill in paperwork. Remove affected country
from any maps of the world or globes which you may happen to own.

TUNGUSKA CLASS IMPACT OCCURS IN ANOTHER REGION OF YOUR OWN COUNTRY: No need
to go in to office for at least several days, if not for several weeks.
Your attendance at funerals in the affected area will not be required, but
expect distant relatives to show up to "visit" indefinitely.

IMPACT MEGA-TSUNAMI HITS ANOTHER REGION OF YOUR OWN COUNTRY: Expect great
deals on beach front property, as soon as anybody can figure out who owned
it. Expect that you may have to have to use force to return home "helpers"
who will have arrived from neighboring countries.

TUNGUSKA CLASS IMPACT OCCURS IN YOUR OWN AREA: When light from the explosion
appears, do not pause to bend over and kiss your *ss goodbye. Drop to the
floor and roll over once to put out the fires burning on your body. In the
seconds left until the blast wave arrives, expel all the air from your lungs
so that they are not burst by the blast wave, bury your nose and mouth into
the floor, and place your hands over your ears so that your eardrums are not
ruptured when it arrives.

IMPACT MEGA-TSUNAMI HITS YOUR OWN AREA: As above, but before beginning your
drive inland, pause to bend over to kiss your *ss goodbye, as that's about
as much of a chance as you have of making it.

EXTINCTION LEVEL EVENT OCCURS: The chances are about 7 out of 8 that you
will not be instantly killed by the blast, but instead have your lungs
completely ruptured. Thus as your life flows out of your body, you will have
anywhere from several seconds to several minutes to seriously contemplate
and reflect on how you spent your time on planet Earth.

Live a good life.

WILL 2002 DJ150 STRIKE THE EARTH IN AUGUST, 2003?

Talk about your agonizing waits. The report on the failure of the CONTOUR
spacecraft will not be completed until the pieces of it are observed on
their return to the Earth sometime in August, 2003. While the JPL navigation
team is still working out their orbits, even if the pieces do hit the Earth
it is not likely that much of them will be able to survive entry through the
Earth's atmosphere. Collectors everywhere will be saddened by this news, since a
nice piece of engine maranging steel would be a great addition to anyone's
collection of space junk.

Star 30 Motors have had the reliability of a brick, but sometimes that snake
is going to come up and surprise you and bite you in the butt no matter what
you do ahead of time. My condolences to Don and Joe and all the CONTOUR team
on a nice try, and I'm sure all Conference participants wish them much
better luck next time.

THAT'S WHY THEY'RE ASTRONAUTS: ASTRONAUT RUSTY SCHWEICKART'S PROJECT B612

Certainly one of the most interesting presentations was that of Astronaut
Rusty Schweikart on his Project B612: http://b612.boulder.swri.edu/

Schweikert spent about $5, 000 to set up a non-profit organization to seek
about several hundred thousand dollars in tax-deductable donations for
undertaking immediate engineering studies towards an interceptor. He named
his organiztion Project B612 after the asteroid which was the home of Le
Petite Prince.

Whatever else it accomplishes, this mechanism is going to allow Schweikart
to alert the leaders of US society of the hazard presented by impact. His
thinking on the matter is that doing this will be more effective than
waiting for the Congress to act, one reason for this being that the public
already thinks that NASA is dealing with the problem.  With his plan, the
system studies could start now.

I first asked Schweikart how he planned to get access to the information on
the nuclear electric powered lasers necessary for diversion by laser
ablative propulsion, and he replied that his proposal would not use them,
but instead rely on giving the impactor a push with nuclear electric powered
engines. I next inquired that since actually building these devices would
require government funding, perhaps the best way to motivate the government might be
through supporting research guided specifically toward demonstrating the
impact threat, such as guided archaeological and geological work on specific
impacts. Schweikart replied that that might work, but that with his plane he
would not have to convince the government to act, but could begin the
engineering studies now.

That's why they're astronauts, Benny. Here I have used personal funds for my
work, for example betting some $5,000 that demonstrating the destruction of
Bazas will ultimately help to motivate the French government to take action,
and betting some $80,000 total of my own personal funds that a good recovery
of the historical record of impact events will motivate my own government to
act.

For $5,000 I could have set up a non-profit and tried to use other peoples
money to do this. As it was, I did not take any time to do this, instead
concentrating entirely on the studies themselves.

That's why they're astronauts. Of course, I, like everyone else here, await
the delivery by that independent Federal agency of their own impact hazard
analysis to the Congress in 2003, and the resulting Congressional action.


APPENDIX 1: A SHORT ANNOTATED LIST OF KNOWN AND SUSPECTED HISTORICAL IMPACTS
AS OF SEPTEMBER, 2002

Most, but not all, of the impact events listed here await detailed
confirmation by field geologists and field archaeologists; those impact
events which have already been confirmed by field studies are indicated by
the lack of an accompanying "?". Known impacts which resulted in no or few
deaths are indicated by "miss".  More detailed information on each separate
impact, pointers to internet sites, and reports on current research may be
found in the Cambridge Conference archives maintained by Bob Kobres at:
http://abob.libs.uga.edu/bobk/cccmenu.html.


CLASS 8 DEFINITION: LOCALIZED DESTRUCTION
"A collision capable of causing localized destruction."
CURRENT FREQUENCY ESTIMATE (adopted by the International Astronomical
Union):
"Such events occur somewhere between once per 50 years and once per 1000
years."

CLASS 8 SUSPECTED(?) AND CONFIRMED HISTORIC IMPACT EVENTS AS OF JUNE 2002:

CA. 2697 BCE - HUANGDI IMPACT, SHAANXI, CHINA
TYPE OF IMPACTOR: Analysis of found fragment not yet published
http://www.china.org.cn/english/30360.htm - Li Yanhun, 1980-2000
http://www1.chinadaily.com.cn/cndy/2002-04-09/64766.html
http://www.greatwallct.com/meteorit.htm
?http://www.jilin.gov.cn/en/sxfm/jl.htm

17 February, 2325 BCE - CAMPO DE CIELO, ARGENTINA
TYPE OF IMPACTOR: IRON
http://www.phy.mtu.edu/~jaszczak/meteorite.html
http://www.star-bits.com/campo.htm
Both Bruce Masse and Oscar Alfredo Turone have been assembling myths from
the area:
http://abob.libs.uga.edu/bobk/ccc/cc032601.html

For a possible Mayan record of this event, see:
http://abob.libs.uga.edu/bobk/ccc/ce010702.html - E.P. Grondine, 2001:
7 September, 2325 BCE - A white headband was closed for White?
17 February, 2325 BCE - Lady White conjured up the gods at Matawil
Note that the meaning of the Mayan locative "Matawil" is still unclear, and
this report may instead relate to the Hurrian impact event (below). Note
also that the rain of molten iron subsequent to the impact of an iron at
higher speeds can result in fires occurring over an area far larger than
that first ignited by the initial impact blast.

CA. 1586 BCE  - DESTRUCTION OF HITTITE FORCES UNDER T'E HANTILISH (JOSHUA
IMPACT EVENT)(?)
TYPE OF IMPACTOR: IRON strongly suspected
There had been much discussion of this impact event prior to my own
involvement, and I hope others will forgive my bias here, but for a first
accurate dating in LM 1B context and possible identification as an iron
impactor see:
http://abob.libs.uga.edu/bobk/ccc/cc032098.html;  - E.P. Grondine, 1998. For
a summation of contemporary (i.l. at 1586 BCE) text and archaeological data
see: http://abob.libs.uga.edu/bobk/ccc/cc021202.html - E.P. Grondine, 2002

CA. 520 BCE  - DESTRUCTION OF ETRUSCAN CAPITOL CITY OF VOLSINII(?)
TYPE OF IMPACTOR: UNKNOWN
See: http://abob.libs.uga.edu/bobk/ccc/cc043098.html - E.P. Grondine, 1998
(I have a collection of Latin texts relating to this impact event sitting on
my desk.  Of course, work with texts is no substitute for field work in
Tuscany.)

CA. 1 BCE  - BRENHAM, KANSAS
TYPE OF IMPACTOR: STONY-IRON
For discovery of the crater, see:
http://www.bigwell.org/meteor.html
For impactor type, see:
http://wapi.isu.edu/Geo_Pgt/Mod05_Meteorites_Ast/Met_ast_pages/brenham_meteorite.htm
For Native American use, see:
On five new American Meteorites; ART. XLII, The American Journal of Science,
George F. Kunz, 1890  (This was 112 years ago, but before nuclear explosions
no one understood the size of the blast.)
For an overview of subsequent work, see:
Cosmic Debris - Meteorites in History, J.G. Burke, 1986, pp. 223-225:
For other contemporary work see:
http://www.maa.mhn.de/Comet/metlegends.html  - Gary W. Kronk
http://www.meteor.co.nz/may96_2.html  - Glen Akridge, 1996
Anthropologist Donald Blakeslee is also currently working through Native
American materials.
For exhaustive abstracts of the anthropological and physical work on Brenham
done since 1890, with full citations, serious researchers may wish to try contacting Bernd
Pauli via the meteorite list.

CA. 645 CE - IMPACT IN DYFED(?)
TYPE OF IMPACTOR: UNKNOWN
http://abob.libs.uga.edu/bobk/ccc/cc052402.html - Melfyn Thomas, 2002
http://abob.libs.uga.edu/bobk/ccc/cc071502.html - Alistair McBeath, 2002

CA. 679 CE - DESTRUCTION OF COLDINGIHAM MONASTERY(?)
TYPE OF IMPACTOR: UNKNOWN
http://abob.libs.uga.edu/bobk/ccc/cc081597.html  - Phil Burns, 1997
Possible lightening strike on tall structure

CA. 838 CE - IMPACT IN BALTIC AND DEATH BY LOCAL TSUNAMI(?)
http://abob.libs.uga.edu/bobk/ccc/cc033099.html - Trevor Palmer, 1999
http://abob.libs.uga.edu/bobk/ccc/ce120500.html - James Palmer & Trevor
Palmer, 2000
For possible mention in contemporary Chinese astronomical records, see:
http://abob.libs.uga.edu/bobk/ccc/cc010301.html

CA. 800 CE - TUNGUSKA TYPE IMPACT AT KEY MARCO, FLORIDA(?)
TYPE OF IMPACTOR: COMET airburst strongly suspected
http://abob.libs.uga.edu/bobk/ccc/ce010702.html  - E.P. Grondine, 2001-2002

CA. 1000 CE +/- 100 - DESTRUCTION OF MAJOR NATIVE AMERICAN CENTER
ALONG THE SAINT LAWRENCE RIVER(?)
TYPE OF IMPACTOR: UNKNOWN
http://abob.libs.uga.edu/bobk/ccc/ce090400.html - E.P. Grondine, 2000

2 SEPTEMBER, 1311 CE - ENGLAND
Gleam enduring many hours, trees burned, church burned
Possible lightening strike on tall structure
http://abob.libs.uga.edu/bobk/ccc/cc022800.html - Roberto Gorelli, 1997

1338 CE - AQUILEIA, NORTHERN ITALY
Lands burned by fire which fell from the sky
No tall structure mentioned
http://abob.libs.uga.edu/bobk/ccc/cc022800.html - Roberto Gorelli, 1997

CA. 1321-1368 CE - ERH RIVER FALL IN CHINA(?)
TYPE OF IMPACTOR: UNKNOWN
"Meteorite Falls in China and Some Related Human Casualty Events."
Meteoritics 29, 864-871, Kevin Yau, Paul Weissman, & Don Yeomans - 1994
This work is not available online.  For extracts, including mention of other
very small impacts, see:
http://www.oberlin.edu/library/sciencelib/geo117/group9/group9.html
http://www.100megsfree4.com/farshores/ameteo.htm

1450 CE - MISS IN WABAR, SAUDI ARABIA
TYPE OF IMPACTOR: IRON
http://minerals.usgs.gov/east/wynn/3wabar.shtml - Jeff Wynn & Gene
Shoemaker, 1997

1490 CE - CH'ING-YANG FALL KILLS OVER 10,000 (POSSIBLY HAIL)(?)
TYPE OF IMPACTOR: UNKNOWN
"Meteorite Falls in China and Some Related Human Casualty Events."
Meteoritics 29, 864-871 Kevin Yau, Paul Weissman, & Don Yeomans - 1994
Article not available online.  For extracts, including other very small
impacts, see:
http://www.oberlin.edu/library/sciencelib/geo117/group9/group9.html
http://www.100megsfree4.com/farshores/ameteo.htm

5 APRIL 5, 1800 CE - NORTH AMERICA(?)
Fall of a large meteorite accompanied by earthquake and overthrow of forest
http://abob.libs.uga.edu/bobk/ccc/cc022800.html  - Roberto Gorelli, 2000

9 OR 19 NOVEMBER, 1819 CE - CANADA AND NORTH OF U.S.
Black rain joined with bolides, tremors of earthquake, and obscuration of
the sky
http://abob.libs.uga.edu/bobk/ccc/cc022800.html - Charles Fort, 1919;
Roberto Gorelli, 1997

11 NOVEMBER, 1836 CE - MISS AT MACAU, RIO GRANDE DO NORTE, BRAZIL
TYPE OF IMPACTOR: STONE, Olivine-bronzite chondrite (H5), veined, 26.27 %
total iron
http://www.meteoritesales.com/met_m.htm - Ken Regelman
After the appearance of a brilliant meteor, followed by detonations, a
shower of stones, some said to weigh from 11lb to 80lb, but most the size of
doves' eggs, fell near the mouth of the river Assn, killing several cattle.

30 JANUARY, 1868 CE - MISS AT PULTUSK, POLAND
TYPE OF IMPACTOR: STONE CHONDRITE
http://www.resologist.net/lands221.htm - Charles Fort, 1923
http://www.meteoriteguy.com/pultusk.htm
http://www.meteoriteguy.com/pultuskslices.htm

8-9 OCTOBER, 1871 CE - GREAT LAKES FIRES(?)
TYPE OF IMPACTOR: COMET, based on 1 recovered sample, possibly COMET BIELA
Air burst leading to fires?
http://www.angelfire.com/mi2/gfmeteor/background.htm#top - Ken Rieli
http://www.angelfire.com/mi2/gfmeteor/evidence.htm

3 FEBRUARY 3, 1882 CE - MISS AT MÖCS, HUNGARY
TYPE OF IMPACTOR: STONE Olivine-hypersthene chondrite (L6), veined, 21.81 %
total iron
http://www.resologist.net/lands221.htm - Charles Fort, 1923
http://www.meteoritesales.com/met_m.htm - Ken Regelman
other reports of over 100,000 stones.

24 FEBRUARY 24, 1885 CE - 37° N.,170° E., PACIFIC OCEAN
Red inflamed sky, blinding mass fell on the ocean and lifted a large mass of
water
http://abob.libs.uga.edu/bobk/ccc/cc022800.html - Charles Fort, 1919;
Roberto Gorelli, 1997

30 JUNE, 1908 CE - MISS (2 DEAD) AT TUNGUSKA, RUSSIA
TYPE OF IMPACTOR: COMET strongly suspected
Summary of current research and internet resources:
http://www-th.bo.infn.it/tunguska/ - another excellent Italian research
effort

10 AUGUST, 1930 CE - MISS AT RIO CURACA IN JUNGLE OF BRAZIL
TYPE OF IMPACTOR: COMET strongly suspected
http://www.xtec.es/recursos/astronom/craters/amazonase.htm
- Leonid Kulik, 1931; N.Vasilyev & G.V. Andreev, 1989;
  Mark Bailey, D.J.Markham, S. Massai, J.E. Scriven, 1995;
  Duncan Steel, 1995
http://www.meteor.co.nz/feb96_2.html
http://www.anomalist.com/reports/tunguska.html - Mark Bailey, 1995; Patrick
Huyghe, 1996

11 DECEMBER, 1935 CE  - MISS IN RUPUNUNI REGION OF BRITISH GUYANA
TYPE OF IMPACTOR: UNKNOWN, but one capable of creating airburst
http://www.xtec.es/recursos/astronom/craters/amazonase.htm  - Serge A.
Korff, 1935

12 FEBRUARY, 1947 CE - MISS AT SIKHOTE ALIN IN KAMCHATKA, RUSSIA
TYPE OF IMPACTOR: IRON
http://www.arm.ac.uk/paseg/Sikhote-Alin-1947.html - E. L. Krinov, Valentin
Tsvetkov
http://www.usm.maine.edu/~planet/galbtxt.html
http://www.alaska.net/~meteor/SAinfo.htm

1972 CE - MISS IN SOUTH WEST PACIFIC(?)
http://www.llnl.gov/planetary/pdfs/Threat/02-Nemtchinov.pdf
http://www.llnl.gov/planetary/pdfs/Threat/02-Boslough.pdf

10 AUGUST, 1972 CE - MISS BY GREAT DAYLIGHT FIREBALL
TYPE OF IMPACTOR: COMET strongly suspected
http://www.astrosurf.com/lombry/Images/impact-teton.jpg
http://www.astrosurf.com/lombry/meteores-anomalies2.htm
(I have not found on the internet as an mpeg file the very impressive movie
of this near miss, and I do not know if anyone has calculated when this
object will return to intercept the Earth.)

1 FEBRUARYT, 1994 - WESTERN PACIFIC
http://www.space.com/scienceastronomy/astronomy/classified_impacts_000502.ht
ml
Edward Tagliaferri
FOR US DEPARTMENT OF DEFENSE DECLASSIFICATION ALSO SEE:
http://www.permanent.com/ref-so-5.htm#1 - Pete Worden
http://www.permanent.com/ref-so-5.htm#9 - Doug ReVelle
http://www.permanent.com/ref-so-5.htm#3 - Grant Stokes

RECENT UPPER ATMOSPHERE DETONATIONS OF IMPACTORS (BOLIDES):
http://phobos.astro.uwo.ca/~pbrown/usaf.html

18 JANUARY, 2000 TAGISH LAKE
TYPE OF IMPACTOR: COMET based on multiple samples recovered
http://phobos.astro.uwo.ca/~pbrown/tagish/


CLASS 9 DEFINITION: REGIONAL DEVASTATION
"A collision capable of causing regional devastation."
CURRENT FREQUENCY ESTIMATE (adopted by the International Astronomical
Union):
"Such events occur between once per 1,000 years and once per 100,000 years."

CLASS 9 SUSPECTED(?) AND CONFIRMED HISTORIC IMPACT EVENTS AS OF JUNE 2002:

DATE UNKNOWN: ENLIL'S PICKAX IMPACT(?)
TYPE OF IMPACTOR: UNKNOWN
Crater identified by Sharad Masters, 2001 -
http://news.telegraph.co.uk/news/main.jhtml?xml=%2Fnews%2F2001%2F11%2F04%2Fwmet04.xml
http://atlas-conferences.com/cgi-bin/abstract/caiq-15
For other comment on possible dating, possible Harappan immigration into
depopulated area, and myths possibly relating to this impact, see:
http://abob.libs.uga.edu/bobk/ccc/cc041702.html - E.P. Grondine, 2002

CA. 5700 BCE - NINURTA/ASAG IMPACT(?)
TYPE OF IMPACTOR: UNKNOWN
http://abob.libs.uga.edu/bobk/ccc/cc041702.html - E.P. Grondine, 2002

CA. MAY 10, 2807 BCE - UTNAPISHTIM/GILGAMESH/ATRAHASIS MEGA-TSUNAMI(?)
So many have worked through the myth materials and flood remains related to
this possible impact and subsequent mega-tsunami that there is not
sufficient space here to cover it all. No less than six versions of the myth
have been preserved: http://www.asa3.org/archive/ASA/200103/0070.html
along with a Hurrian version. Bruce Masse is currently working through the
myth materials, and arrived at 2807 BCE as the date of the Indian Ocean
impact and resulting tsunami

2318-2278 BCE - THE ULLIKUMMI HURRIAN IMPACTOR
TYPE OF IMPACTOR: COMET

Archaeologist Claude Schaeffer (1948) was the first to notice simultaneous
destruction levels in the ancient Near East: Stratigraphie Comparee et
Chronologie de l'Asie Occidentale: IIIe et IIe Millenaires, Oxford
University Press, Oxford & London, 1948. His work then languished:
http://abob.libs.uga.edu/bobk/ccc/cc022497.html
http://abob.libs.uga.edu/bobk/ccc/cc070497.html
until in an attempt to resolve the cause of these destructions, the lead
excavator of the site of Tel Leillan, Harvey Weiss, called in French soil
specialist Marie-Agnes Courty.

By 1997, Courty believed she had identified a local strata of impact origin:
http://personal.eunet.fi/pp/tilmari/tilmari2.htm
though other members of the team strongly argued for volcanic or natural
cyclic climatic effects as the cause of the simultaneous destruction levels.

By 1999, a Hurrian account of a cometary impact had been recovered:
http://abob.libs.uga.edu/bobk/ccc/cc012099.html - E.P. Grondine, 1999

and for a contemporary illustration of this impact event, see:
http://www.louvre.fr/anglais/collec/ao/sb0004/ao_f.htm  - identified, E.P.
Grondine, 2002

For a possible absolute dating of this impact event, see:
http://abob.libs.uga.edu/bobk/ccc/cc041702.html - E.P. Grondine, 2002

Based on the soil record, it appears that the effects of this impact event
may have been regional, and not global in scope. The causes of Near Eastern
droughts are still under debate, and for the current problems caused in
differentiating impact debris from volcanic ash and wind blown top soil,
see: http://www.knowledge.co.uk/sis/abstract/courty.htm

For an attempt at an absolute dating of the droughts during this period,
see:
http://abob.libs.uga.edu/bobk/ccc/cc041702.html - E.P. Grondine


CA. 1500 BCE - INCINERATION OF CITY OF MOHENJO DARO(?)
TYPE OF IMPACTOR: COMET strongly suspected
Site excavators found bodies lying scattered in the streets of "The City of
the Dead", with no evidence of wounds or weapons, and signs of
"vitrification" by intense heat - remains consistent with the air burst of a
cometary impactor of the Tunguska type. These "mysterious" remains, in
combination with heavily nationalistic archaeologies and poorly understood
myths, have lead to a great deal of nonsense. To my knowledge no one is
currently seriously working with either these physical remains or with the
impact myths.  Nonetheless, both the physical remains and the myth materials
remain what they are.
http://www.itihaas.com/ancient/contrib2.html
http://personal.eunet.fi/pp/tilmari/tilmari3.htm - Timo Niroma, 1998
http://www.meteorobs.org/maillist/msg19734.html - E.P. Grondine, 2000
http://abob.libs.uga.edu/bobk/ccc/cc092600.html - E.P. Grondine, 2000

CA. 635-570 BCE - KAALI LAKE IMPACT
TYPE OF IMPACTOR: IRON
http://www.muinas.ee/ecp/kaali/en/index.html
Ivan Reinvald, 1928-1941; Agu Aaloe, 1955-1980; Lennart Meri, 1976
For an overview, see:
http://abob.libs.uga.edu/bobk/ccc/cc062402.html

CA. 300 BCE - DEVASTATION OF AINU PEOPLE OF JAPAN(?)
TYPE OF IMPACTOR: UNKNOWN
http://abob.libs.uga.edu/bobk/ccc/cc102898.html - E.P. Grondine, 1998
Jomon ends in southern Japan, appearance of Yayoi culture, with Ainu impact
myth.  To my knowledge, no one fluent in Japanese is working on these
materials.

CA. 500 CE - IMPACT TSUNAMI HITS WESTERN AUSTRALIA
TYPE OF IMPACTOR: UNKNOWN
http://abob.libs.uga.edu/bobk/ccc/ce053101.html
Ted Bryant, Bob Young, Duncan Steel, 1989-1996

580 CE - IMPACT IN CENTRAL EUROPE(?)
TYPE OF IMPACTOR: FRAGMENT OF COMET
http://abob.libs.uga.edu/bobk/ccc/ce082202.html - E.P. Grondine, 2002

580 CE - DESTRUCTION OF CITY OF BAZAS AND SURROUNDING REGION
TYPE OF IMPACTOR: FRAGMENT OF COMET
http://abob.libs.uga.edu/bobk/ccc/cc081597.html  - Phil Burns, 1997
http://abob.libs.uga.edu/bobk/ccc/ce082202.html - E.P. Grondine, 2002

585 CE - DESTRUCTION OF TWO ISLANDS IN BAY OF BISCAY(?)
TYPE OF IMPACTOR: FRAGMENT OF COMET
http://abob.libs.uga.edu/bobk/ccc/cc081597.html - Phil Burns, 1997
http://abob.libs.uga.edu/bobk/ccc/ce082202.html - E.P. Grondine, 2002

CA. 750 CE - GREAT RAFT FORMATION, LOUISIANA(?)
TYPE OF IMPACTOR: UNKNOWN
Currently unknown if caused by impact, hurricane, or methane hydrate
explosion
http://abob.libs.uga.edu/bobk/ccc/ce090400.html - dating, E.P. Grondine,
2000
(I believe Bob Kobres was the first to raise this possibility, but I can not
find a link)

CA. 1200 CE - BALD MOUNTAINS IMPACT(?)
TYPE OF IMPACTOR: UNKNOWN
Event leads to migration of Cherokee into depopulated area?
http://abob.libs.uga.edu/bobk/ccc/ce090400.html - E.P. Grondine, 2000

CA. 1500 CE - AUSTRALIAN GREAT WALL OF WATER
TYPE OF IMPACTOR: UNKNOWN
http://abob.libs.uga.edu/bobk/ccc/ce053101.html
Ted Bryant, Bob Young, Duncan Steel, 1989-1996
With collapse of Polynesian megalithic cultures on Ponhpei and elsewhere


CLASS 10 DEFINITION: GLOBAL CLIMATIC CATASTROPHE
"A collision capable of causing global climatic catastrophe."
Current stated IAU (International Astronomical Union) frequency estimate:
"Such events occur once per 100,000 years, or less often."

CLASS 10 SUSPECTED(?) AND CONFIRMED HISTORIC IMPACT EVENTS AS OF JUNE 2002:

CA. 3114 BCE -
TYPE OF IMPACTOR: COMET, possibly COMET ENCKE

By 1998, climate researcher Timo Niroma had noticed several simultaneous
events centered around this date: Stonehenge I had been constructed, and the
date was significant in the Mayan Calendar.  Niroma had also begun to work
through the myths, in particular hypothesizing on tsunami leading to flood
myths (Battle of Titans?): http://personal.eunet.fi/pp/tilmari/tilmari3.htm

For Mayan records of this event, see:
http://abob.libs.uga.edu/bobk/ccc/ce010702.html - E.P. Grondine, 2001:
16 June, 3122 BCE    - The First Maize Revealer Partitioner is born
7 December, 3121 BCE - Birth of Lady White (?)
13 August, 3114 BCE  - Image made visible at Closed Sky, the First Three StonePlace;
                       Event for The First Maize Revealed Partitioner
5 February, 3112 BCE - The First Maize Revealed Partitioner enters the sky,
                       Prepared/Dedicated the Raised Up Sky Place in the North
                       Set in motion the Raised Up Sky Heart

25 October, 2360 BCE - GREAT SOUTH AMERICAN FIRE; END OF MAYA FIRST
CREATION(?)
-
TYPE OF IMPACTOR: COMET, possibly COMET ENCKE

Following Peter Schultz's mistake in the identification and dating of the
Rio Cuarto features,
http://usuarios.lycos.es/CRATERES/index.htm
http://news.nationalgeographic.com/news/2002/05/0509_020509_glassmeteorite.h
tml
Anthropologist Bruce Masse assembled South American folk myths relating to a
great fire:
http://www.msnbc.com/news/373938.asp?cp1=1
http://atlas-conferences.com/cgi-bin/abstract/caiq-36

For Mayan records of this event, see:
http://abob.libs.uga.edu/bobk/ccc/ce010702.html - E.P. Grondine, 2001:
8 November,  2360 BCE - Birth of the Red Dwarf(?) Partitioner
25 October,  2360 BCE - Birth of Sun-eyed Torch, The killer of the kings in
                        the White House, the White Bone House, the ?? of the heavens,
                        who with fire closed the eye of the Sun-eyed Lord Sun;
                        "arrived" (struck) at or from "Matawil"
21 October,  2360 BCE - Birth of G1

For a possible Near Eastern dating of this event, see:
http://abob.libs.uga.edu/bobk/ccc/cc041702.html - E.P. Grondine, 2002

CA 1150 BCE - ATLANTIC IMPACT MEGA-TSUNAMI DEVASTATES COASTAL CENTRAL AND
NORTH AMERICA
TYPE OF IMPACTOR: UNCERTAIN, possibly dates with COMET ENCKE return
http://abob.libs.uga.edu/bobk/ccc/ce010702.html - E.P. Grondine, 2001
General migration in Eastern Mediterranean follows

ca. 536 CE - CLIMATE COLLAPSE
TYPE OF IMPACTOR: dates with COMET ENCKE return
Dust loading leads to sub-Roman times becoming sub-Roman. Global climate
collapse and starvation.  Possible combination of cometary and volcanic
dust.
"Dendrochronology raises questions about the nature of the AD 536 dust-veil
event", M.G.L. Baillie, The Holocene  4, 2, 212-217, 1994
http://abob.libs.uga.edu/bobk/ccc/ce082202.html - E.P. Grondine, 2002
Summation of current research:
http://www.pbs.org/wnet/secrets/flash/catastrophe1_script.html
http://www.pbs.org/wnet/secrets/flash/catastrophe2_script.html
Current discussion:
http://www.ad536.org/ad536/


CA. 830-875 CE - CLIMATE COLLAPSE DUE TO INTERCEPTION OF COMET DEBRIS
STREAM(?)
TYPE OF IMPACTOR: COMET(?)
http://abob.libs.uga.edu/bobk/ccc/cc033099.html - Trevor Palmer, 1999
http://abob.libs.uga.edu/bobk/ccc/ce120500.html - James Plamer & Trevor
Palmer,
2000
For Chinese records, see:
http://abob.libs.uga.edu/bobk/ccc/cc010301.html


WORK ON RECENT HISTORICAL IMPACTS IN PROGRESS

Information on both tsunami and airburst impact events affecting the Maori
of New Zealand is currently undergoing analysis by Peter Snow. I have also
been informed by Richard Wade that initial data on historical impact events
in Africa will be published in the very near future.  Bruce Masse's work on
South American and other myths continues. Ed Sugrue, Annette Kolodny, and
Melissa Ryan are currently working through Native American materials
relating to historical impacts in North East North America. I have also been informed that the
United States' National Academy of Science is working on an impact risk
assessment due in 2003.

The Indian Space Research Organization has suspended its work in translating
and publishing ancient Indian astronomical records and transferred those
funds to military related tasks.


WERE THE IMPACTS PERIODIC?

How is Clube and Napier's original hypothesis that several impact events
were related to the regular returns of Comet Encke holding up? Mike Baillie
has provided a short list of demonstrated periodicity in tree ring data:
"The tree-ring record points to global environmental traumas between 2354
and 2345 BC, 1628 and 1623 BC, 1159 and 1141 BC, 208 and 204 BC and AD 536
and 545...",  which appears to show specific support for it.  While
archeological excavation data currently seldom provides sufficient time
resolution for astronomical work, some ancient text records are sometimes
pretty adequately dated, particularly those with astronomical references,
with Mayan text records being very date specific indeed.  While the 2360 BCE
return of Comet Encke appears to be mentioned by text, and the 1159 BCE
return of the Comet indicated by mega-tsunami, and the 536 CE return
implicated in the climate collapse which occured then, the explosions of the
volcanic island of Thera ca 1628 BCE makes it very difficult to separate out
the data on the effects of any return in this period. For the 208 BCE window
of Comet Encke's return, so far there appears to have been little
archeological evidence recovered of the interception of its debris field,
and in particular no evidence of impact events. But this is only a summation
of current knowledge, and all of this most likely will change significantly
as work on the archaeological record continues.

Almost no work has been done to date on the periodicity of other impacts,
and whether these impacts may relate to the regular return of other comets
or of asteroidal debris streams.  No doubt this is due for the most part to
the simple fact that so little reliable data on the impacts themselves has
been recovered to date. If the historical impact record is to be recovered,
money needs to be spent on targeted research in the field.

Bernd Pauli has done very limited work on the regular annual return of
meteorite streams, and I expect that meteoriticist Ken Regelman may take
this work up soon as well.

PREHISTORIC IMPACTS AND MAN

A MASSIVE IMPACT AT THE BEGINNING OF THE HOLOCENE

German rocket scientist and inventor Otto Muck was probably the first to
note a number of geological anomalies indicative of a massive impact event
at the start of the Holocene:
Atlantis gefunden: Kritik und Lösung des Atlantis-Problems, Stuttgart,
Victoria Verlag, 1954

The retired British geologists Derek Allan and Bernard Delair continued with
the assembly of these anomalies in their book, When the Earth Nearly Died,
1995, now published as Cataclysm: Compelling Evidence of a Cosmic
Catastrophe in 9500 B.C., 1997, which contains an exhaustive bibliography.
While the anomalies Allan and Delair list are indicative of impact, their
work has often been used by others to support the most extravagant
astronomical and anthropological claims.

For a review of the book, see Trevor Palmer's comments at:
http://abob.libs.uga.edu/bobk/ccc/ce102899.html

For North American anthropological restraints on the date of this impact
event, see:
http://abob.libs.uga.edu/bobk/ccc/ce010702.html

For a possibly related African neolithic site, see:
http://www.colorado.edu/PublicRelations/NewsReleases/1998/Oldest_Astronomical_Megalith_A.html

AN IMPACT WITNESSED BY HOMO ERECTUS

Stone tools have been found at a massive impact crater in Asia which dates
frome some 803,000 years ago: Mid-Pleistocene Acheulean-like Stone
Technology of the Bose Basin, South China; Hou Yamei, Richard Potts, Yuan
Baoyin, Guo Zhengtang, Alan Deino, Wang Wei, Jennifer Clark, Xie Guangmao,
and Huang Weiwen, Science March 3 2000: 1622-1626.
For extracts, see:
http://home.earthlink.net/~exonews/ancients/oldest_stone.htm
http://abob.libs.uga.edu/bobk/ccc/cc030600.html

A NARROWING OF THE DNA POOL

Several teams of researchers studying changes in human DNA have recently
noted that there appears to have been a reduction of the human population to
around 100 individuals, but the point in time when this occurred as well as
where it occurred are both not yet adequately constrained enough to allow
tieing it to an impact event.

E.P. Grondine epgrondine@hotmail.com
Oak Knoll Farm, Burr Hill, VA. 22433
tel. 540-854-4429
(Cash always welcomed)



CCCMENU CCC for 2002

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