PLEASE NOTE:


*

CCNet DIGEST, 15 June 1998
--------------------------

(1) HEADQUARTERS AND FIELD CENTERS
    Ed Grondine" <epgrondine@hotmail.com>

(2) SOME COMMENTS, FROM AN INTERNATIONAL PERSPECTIVE, ON CLARK
    CHAPMAN'S "RESPONSE TO CONGRESS FOR AN NEO PLAN"
    Jonathan TATE <fr77@dial.pipex.com>

(3) US HOUSE SUBCOMMITTEE HEARING ON NEOS
    David Morrison <dmorrison@arc.nasa.gov>

(4) ASTRONOMERS FIND NEARBY STARS CONSTANTLY BOMBARDED BY COMETS
    Andrew Yee <ayee@nova.astro.utoronto.ca>

(5) THE IAU's EDGAR WILSON AWARD
    IAUC 6936
    http://cfa-www.harvard.edu/iau/special/EdgarWilson.html

=====================
(1) HEADQUARTERS AND FIELD CENTERS

From Ed Grondine" <epgrondine@hotmail.com>

Benny -

Let me start by apologizing to Dr. Levy for continuing this debate, but
I agree with you that its not about personalities but instead about the
future of international cooperation in the NEO search.

Having gone through stacks of records from the Soviet, Russian, and
Chinese space programs, I am pretty skilled at cutting through the
"bureaucratese", and perhaps I may call to your attention some of the
finer "points" of Chapman's response to the Subcommittee. At least this
time I don't have to deal with some of the more "theoretical" aspects
of Soviet socialism or Mao or Deng thought!

The first thing to remember is that NASA is not a monolithic entity and
that in the past there have been disagreements between NASA
headquarters and the field centers as to roles and responsibilities.
There have been several books written on the history of this subject
alone.

Dr. Huntress at HQ clearly stated to me that he thought that the MPC
would play the international coordinating role in the survey and that
NASA would cooperate with it.

Dr. Chapman has suggested otherwise:  

>(4) Support a center (analogous to the Minor Planet Center), at an
>adequate level for the greatly increased discovery rates anticipated,
>to oversee and coordinate the Survey; to collect, disseminate, and
>archive the data; to perform routine calculations to track discovered
>near-Earth asteroids; and to provide ephemerides for astrometric or
>physical observational follow-up. Additionally, support the research
>community to evaluate the ongoing results of the Survey in the >context
of the impact hazard.
>
>(5) Coordinate with existing international efforts and broaden
>international participation in the Survey.

You've already called attention to Dr. Chapman's use of "analogous",
and I will examine his response in detail a little later. While one
might hope that Dr. Chapman is calling for an improved US center
separate from the MPC, for the meantime note that in (5) Dr. Chapman
does not inform the committee that the MPC currently is responsible for
such international coordination as currently exists.

Now if Dr. Chapman wishes to relieve the MPC of its current
international responsibilities that is one thing and he should
explicitly state it and justify the recommendation; but I doubt if the
Subcommittee is going to appreciate it if he repeatedly fails to inform
them of the MPC's existence and current work, i.e.:

>research program); lead responsibility should be by NASA but there
>should be specified, supporting roles for the USAF and other
>potentially relevant federal entities (e.g. DOE, FEMA).

Where he fails to mention the MPC again. As I understand it MPC is
under the Smithsonian, which is a separate federally chartered and
funded entity. 

Dr. Chapman also does not wish to offend other NASA officials, and one
might assume that he thinks he will need their support for his plan:

>(4) Mandate (e.g. in authorization language) that NASA fully (not
>partially) implement the Survey and provide (in NASA's appropriations
>bill) an appropriately funded line item for the Project, not to be
>taken from existing scientific research programs.

Maybe NASA will be able to get more money from the Congress, but my
sense of what the Subcommittee intended was for NASA to take money from
"existing scientific research programs", including canceling them if
need be.  This is the kind of hard decision that NASA HQ faces all the
time, while the NASA centers do not.    

Moving on:

>(5) Facilitate international meetings so that U.S. scientists and
>representatives of relevant U.S. agencies meet and coordinate with
>counterparts from other countries (including national space agencies,
>international scientific unions, etc.). These meetings should include
>not only astronomers but also experts in risk management, hazard
>mitigation, etc. Since the impact hazard is international in scope,
>the goal of these meetings should be to establish an international
>framework within which the U.S. Spaceguard Survey Project can operate
>in an independent but coordinated way and to foster
>augmented international participation.

Dr. Chapman does not propose that the MPC, IAU or UN Committee on
Space conduct these meetings; instead he explicitly gives the IAU (and
by implication the MPC) a participant role.

Moving on to his clarification:

>Obviously, whatever entity oversees the Spaceguard Survey will have to
>be different from the MPC, at least in the sense that it must be
>augmented in scale and will have additional responsibilities. I think
>that the current MPC would be the obvious front-runner in proposing to
>take on these responsibilities. But it is not the only option. There
>was discussion at the Spaceguard Workshop in Volcano in 1995 that  
>the Spaceguard Foundation might oversee the project. One can imagine 
>other bidders.  Notwithstanding recent mistakes by the MPC, I think it
>has generally performed its function very well and with dedication.
>Brian Marsden's operation seems to me to be the obvious choice to take
>on these new responsibilities. But, then, I haven't seen other
>proposals nor, indeed, have bids even gone out!

But this begs the question as to why there is a requirement for a
bidding process, as well as the most important point, WHO EXACTLY DOES
HE PROPOSE CONDUCT THIS BIDDING?  

My understanding is that Dr. Marsden is attempting to perform the MPC's
work with just one full time assistant and one part time assistant. It
seems to me that one obvious way to improve the NEO detection effort is
to make sure that the MPC is adequately funded, but that's not what Dr.
Chapman proposes. Instead he states that the MPC is inadequate to the
task, proposes no new funding, and then suggests that the MPC will have
to "bid" to continue its current role, as well as any of the additional
international roles which he has set out above.
  
One glaring deficiency in Dr. Chapman's proposals is that he seems to
be completely oblivious as to the responsibilities of the astronomical
communities in Russia, China, Japan, and the E.U. member states to
their respective defense establishments. In the end, final approval on
the structure of the US NEO detection program to be proposed to the
Congress will be undertaken by Dr. Huntress and Dr. Goldin in
cooperation with Gen. Estes and commanders of the Air Force programs,
and I doubt that any of these gentlemen are similarly unaware of those
responsibilities.

                      Best wishes,
                      E.P. Grondine

========================
(2) SOME COMMENTS, FROM AN INTERNATIONAL PERSPECTIVE, ON CLARK
    CHAPMAN'S "RESPONSE TO CONGRESS FOR AN NEO PLAN"

From Jonathan TATE <fr77@dial.pipex.com>

Firstly, it is tremendous to see that the subject of the NEO hazard is,
once more, being taken seriously at high level in the United States.
Would that this was the situation elsewhere.

While I understand that this document was prepared for a United States,
audience, my main concern with the plan, as laid down in Dr Chapman’s
document, is that it appears to be an entirely American affair. 
Although international co-operation is mentioned briefly in the
introduction and then in the last paragraph of the proposal, the
remainder of the document concerns itself solely with the United
States’ efforts. This harks back to the rather odd proposals for NEO
reporting procedures that were bandied around in the wake of the XF11
affair.

It has always been an act of faith amongst the NEO community that any
major detection programme must be international, and for very sound
reasons. Indeed, Gene Shoemaker himself was adamant on this point.  So
let us assume that any sensible programme will be international in
nature.  Sure, the United States will probably be the major
contributor, but this does not automatically confer the right of
dominance in the field. Perhaps I have misread the situation totally,
but it seems to me that the international community has immense
resources to offer, and that one nation cannot, and indeed should not 
“go it alone” on a matter of such importance to us all.

The proposal calls for the building of two additional telescopes, so,
rather than agonising over the necessary financial expenditure required
to establish the whole programme, the United States should be making
strenuous efforts to encourage other nations to participate.  In the
United Kingdom there is a staggering lack of action and initiative at
government level, but how that would change were it to be made clear
that the United States was taking the whole business very seriously! 
The UK has assets that could be invaluable to the global effort; the
facilities available at the AAO for instance, and indeed the UKST,
which has already been the subject of a proposal to make it a key part
of the Spaceguard network.  A serious word in the right ear from the US
government would be of inestimable value in situations like this.

The message is, don’t try to go it alone.  Put the other members of the
international community under pressure to participate in what everyone
agrees has to be a global project.  With a truly international
programme, cost burdens and expertise will be shared, data will be
freely available, and the right facilities will be dedicated to the
right job.

Jay Tate
Spaceguard UK

=======================
(3) NEO News (6/12/98): US HOUSE SUBCOMMITTEE HEARING ON NEOS

From David Morrison <dmorrison@arc.nasa.gov>


NASA MEMORANDUM FOR THE RECORD, by Barbara Cherry, Legislative Affairs
Office

SUBJECT: "Asteroids: Perils and Opportunities" hearing before the
Subcommittee on Space and Aeronautics, Committee on Science, May 21,
1998.

MEMBERS Rohrabacher, Chairman, (R-CA), Brown (D-CA),  Cook (R-UT),
Gordon (D-TN),

PRESENT: Bartlett (R-MD), Hall (D-TX), Roemer (D-IN), Weldon (D-FL),
Luther (D-MN)

WITNESSES: Dr. Clark Chapman, Southwest Research Institute; Dr. William
Ailor, The AerospaceCorporation; Dr. Gregory Canavan, Los Alamos
National Laboratory; Dr. John Lewis, University of Arizona; Dr. Carl
Pilcher, NASA.

OPENING STATEMENTS: Chairman Rohrabacher opened the hearing by
commending Congressman Brown for his leadership and long track record
of pushing the Executive Branch to deal with the issue of cataloging
and characterizing asteroids. He stated that the potential impact of
these hazardous objects is one of national security, economic as well
as scientific interest. Congressman Rohrabacher noted that the
potential to mine asteroids for metals, minerals and other resources
that can be used to build large structures in space was an important
aspect of the hearing. Mr. Rohrabacher chided NASA for not "walking the
talk" by funding the Near Earth Object (NEO) search program at the
levels suggested in the Shoemaker Report. He noted that NASA has no
trouble finding $50 million for a program pushed by the Vice President
to transmit pictures of Earth into everyone's living room and cannot
find a few million dollars to increase the likelihood of cataloguing
all of the potentially hazardous NEOs l km or larger.

Congressman Brown echoed his long-standing interest in this subject and
the importance of addressing the issue of cataloging and characterizing
NEOs even though the risk of impact is small because of the enormous
potential catastrophic consequences.

Dr. Chapman discussed the "possibility that an asteroid or comet might
strike Earth in our lifetime, perhaps destroying civilization as we
know it." He presented a chart which illustrated the chances of dying
from an asteroid impact against selected other causes (USA). 
Congressman Cook noted that the chances of dying from an airplane crash
and from an asteroid impact were both l in 20,000.

Dr. Chapman noted that if a mile-wide asteroid hit earth, it would
create a hole larger than Washington DC, it would be deeper that 20
Washington monuments stacked on top of each other, ruin agriculture
production, and hundreds of millions to billions of people would die. 
He noted that the consequences were devastating and, therefore, it was
prudent to implement the recommendations contained in the Shoemaker
Report of cataloging 90% of all of the NEOs with diameters of 1 km or
larger within a decade. This would reduce by a factor ten the
uncertainty of knowing if an asteroid were headed toward Earth and
would likely provide sufficient time to try and deal with the
situation.

Dr. Pilcher testified that NASA is committed to the goal of cataloging
90% of all of the NEOs with diameters larger than 1 km within a decade
and that we are on track to do so. He stated that NASA has a rich
program of research on asteroids and comets which will provide
essential information if the Nation were ever to divert an asteroid. 
Dr. Pilcher stated that the Space Science Strategic Plan includes as a
objective, to catalog 90% of the NEOs with diameters larger than 1 km
within 5-6 years and NASA has put into place a program to do this.  Dr.
Pilcher stated that the budget has been doubled to $3 million and NASA
will maintain at least this level of funding in the future. Dr. Pilcher
outlined all of the elements of the NEO Search program and where
increases in the budget have enabled NASA to support new activities. 
He discussed the Partnership Council, a Council chaired by the
Administrator and General Estes of the Air Force to discuss issues of
mutual concern to both agencies - NEO detection is one issue which the
Partnership Council is addressing.  Dr. Pilcher stated that the only
recommendation that NASA is not implementing from the Shoemaker Report
was the recommendation to build a dedicated 2 meter telescope -
-because planned upgrades to existing telescopes can do the job.  Dr.
Pilcher told the Committee that NASA would do what it takes to do the
job right.

Dr. Canavan's testimony addressed several issues. He stated that new
technology developed since the Shoemaker Report was issued has
increased the detection rate. He emphasized that one area that has not
been addressed is long period comets whose orbits intersect the Earth. 
He said there is no clear concept how to do this and it may constitute 
as high as 50% of the threat. Dr. Canavan also stated that
characterization of asteroids is important if one were to try and alter
the course of an asteroid or comet.  He discussed the Clementine II 
mission, which he said represented excellent collaboration between NASA
and DOD before it was canceled. Dr. Canavan closed by saying that the
current level of funding for NEO searches is 1/3 to _ too low to
adequately do the job.

Dr. Ailor discussed the risk the Leonid meteor shower will pose this
November.  He stated that in a normal year one see 10-15 meteors per
hour and this November there will be as many as 200-5,000 meteors per
hour traveling at a speed of approximately 155,000 miles per hour.  He
discussed the recommendations from a recent Conference that was held to
address this issue: 1) During the period, satellite controllers should
be on duty and check the health of the satellites frequently, 2) orient
satellites so that sensitive components are shielded from the oncoming
stream of particles and 3) recovery plans should be in place in the
event of a system failure.

Dr. Lewis discussed the economic value of asteroids as a source to mine
minerals and materials for earth or to produce materials in space for
future space transportation.  He noted  the very low departure speed
required to lift off from an asteroid for a return trip to Earth. Dr.
Lewis stated that the keys to successful importation of materials from
space are lower launch costs and careful choice of exploitation targets
to favor those that are most accessible and have the richest resource
concentrations.

QUESTIONS:  Chairman Rohrabacher stated that NASA has not been spending
adequate funding to search for NEOs as recommended in the Shoemaker
Report. Dr. Pilcher noted that, the Office of Space Science has issued
their Strategic Plan which includes a goal of cataloging 90% of the 1
km asteroids, that NASA funding wasn't adequate to accomplish this
goal, and NASA had doubled the funding of the NEO program.

Mr. Rohrabacher asked Dr. Pilcher how many of the asteroid missions he
discussed were actually in the budget.  Dr. Pilcher replied that  DS-1,
DS-4, Contour, STARDUST, Comet Nucleus Sample Return, and Pluto Kuiper
Express were all assumed in NASA's budget.

Congressman Gordon asked if NASA was the only Agency working on the
problem.  Dr. Pilcher responded that NASA supports researchers at
Universities to address this issue and works closely with the Air Force.
He stated that NASA is developing collaborations with the international
community as well.  Mr. Gordon asked if the Federal Government was
coordinating adequately.  Dr. Chapman responded that FEMA has little
appreciation for the hazard of such an event.  Dr. Canavan stated that
interagency cooperation between NASA and the Air Force hasn't
percolated down to the troops beyond the Administrator and General
Estes.

Congressman Hall asked if we have to have a calamity before anyone
takes something seriously and noted that it is an international problem
and should have international participation.  He asked how much NASA is
spending on search activities.  Dr. Pilcher responded that NASA is
spending $3 million per year and approximately $1 billion over the next
decade in asteroid/comet missions. Mr. Hall questioned if NASA is
actually spending all of the money allocated for the purposes which the
Congress appropriated the funds, indicating that Life and Microgravity
funding was being spent for hardware and not research.

Mr. Roemer noted that Dr. Chapman had provided the sound bite for the
evening news - that "a mile wide asteroid could hit the Earth tomorrow
and we wouldn't know anything about it."  He asked if the Federal
Agencies had held discussions among themselves on what you would need
to do to coordinate a response if an impact were imminent.  The
witnesses indicated that not much had been done.

Mr. Rohrabacher stated that one needs to put things in perspective and
perhaps we aren't spending money wisely.  He noted that Mission to
Planet Earth is budgeted at $1.4 billion and perhaps it makes more
sense to spend additional money on looking for NEOs  and improving
interagency coordination instead of spending money on Mission to Planet
Earth. He stated that he hoped the Congress would move forward and lay
the ground work for the Clementine II mission.

Congressman Hall said he thought the hearing was a waste of time unless
"we arrive at some actions - if it is money we need to know how much."
Both he and Congressman Rohrabacher charged each of the witnesses to
draft a two page action plan on what is needed to address the NEO issue
and what policies need to be developed to meet the challenges that a
NEO impact threat poses.

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

Statement on The Threat of Impact by Near-Earth Asteroids by Dr. Clark
R. Chapman, Southwest Research Institute (for a version of these
remarks that includes the figures, see
www.boulder.swri.edu/clark/hr.html)

====================
(4) ASTRONOMERS FIND NEARBY STARS CONSTANTLY BOMBARDED BY COMETS

From Andrew Yee <ayee@nova.astro.utoronto.ca>

University of California-Berkeley

NEWS RELEASE: 06/11/98

UC Berkeley astronomers find comets around two nearby stars, indicating
the likelihood of planets forming

By Robert Sanders, Public Affairs

BERKELEY -- Space scientists at the University of California, Berkeley,
have found two nearby stars that appear to be continually bombarded by
comets, thought by many to be the building blocks of planets.

The two stars, each about 450 light years from Earth, bring to four the
number of known solar systems so young that their inner regions are
still peppered with comets.

Because planets are thought to coalesce from the collision of comets
and asteroids, it is likely that planets are forming within the gas and
dust surrounding these stars.

"Observations of comet-like bodies, or 'planetesimals,' outside of our
solar system are of great importance in understanding the role of
comets in the formation of all planetary systems," said Barry Y. Welsh,
a researcher in interstellar gas studies at UC Berkeley's Space
Sciences Laboratory. "Our observations indicate a high level of
cometary activity in these disk systems suggesting that there is
potentially plenty of raw building material for new planetary bodies."

Welsh and colleagues Nahide Craig of UC Berkeley and Ian Crawford of
University College, London, England, reported data on the two stars --
HD85905 and HR10 -- at the June 7-11 meeting of the American
Astronomical Society in San Diego, Calif.

Both stars show clear evidence of surrounding disks of gas and dust,
Welsh said. Until recently, only one star -- Beta Pictoris -- was known
to possess both proto-planetary dust and gas clouds, although dust
disks have been observed around perhaps a dozen other stars.

It seems likely that the stars' gravity is pulling swarms of
kilometer-sized solid bodies out of the surrounding dust disk into
highly elliptical orbits, which bring the comets within about 100
million miles of the stars' surfaces, where they are destroyed.

The discovery was made during two observing runs in 1997 from the
1.5-meter telescope at the Cerro Tololo Observatory in Chile. The
telescope's high resolution spectrograph showed highly variable
features that could only be attributed to the evaporation of large
blobs of gas, presumably originating in the nuclei of comets as they
approached close to the central stars.

"Our observations show large changes in the amount of gaseous calcium
and sodium from night to night," Craig said. "The amounts seen are
consistent with the evaporation of gas from comet-like objects, similar
to the huge tails of glowing gas that many people in North America saw
last year from Comet Hale-Bopp. These observations show identical
behavior to that routinely seen towards the star Beta Pictoris, a
well-known candidate proto-planetary system."

Beta Pictoris is the preeminent example of a solar system whose central
star is being hit by continual swarms of gaseous bodies, probably
comets. Since 1984, when Beta Pictoris was found to be surrounded by a
disk of dust -- presumably a swirling planetary nursery -- astronomers
have trained telescopes and radio dishes on the star in search of
actual planets.

This intense study turned up a surprise in 1985, when a doughnut of gas
was found around the star. Even more surprising, bursts of gas seemed
to pop up almost daily, a phenomenon attributed to comet-like bodies,
or planetesimals, falling into the center of the system and spewing out
gas as they are heated by the star. Presumably the comets are pulled in
from the dust cloud surrounding the star, just as comets in our solar
system today are pulled from a distant concentration of comets called
the Oort Cloud.

Despite intense searches, no similar star systems with cometary
activity were found until last year, when variable ultraviolet gas
cloud emissions indicated the presence of newly forming proto-planets
around HD100546, a star also known to have a dusty disk. The UV
emissions were detected by Carol Grady of Eureka Scientific, Inc., and
coworkers using the International Ultraviolet Explorer
satellite.

Welsh and his colleagues thought of a simpler way to look for systems
like Beta Pictoris: search out stars that resemble Beta Pictoris as
closely as possible.

"I made a list of everything we knew about Beta Pictoris from an
astronomical viewpoint, and then I looked for stars with these
characteristics," Welsh said. "How hot it is, how old it is, is there
dust, how fast is it rotating?"

Welsh and his colleagues identified some 40 candidates and were able to
look at six of them for five or more separate nights last year. Two
showed clear evidence of gas bursts.

"I've discovered a cheap way to find them," Welsh said. "The only
difficulty is that you have to look for many nights at these objects,
and it is hard to get sufficient telescope time for that."

Gas can be detected around a star because it absorbs starlight. In
looking at Beta Pictoris, astronomers noticed not only absorption from
a doughnut of gas around the star, but also additional absorption that
seemed to appear and disappear on a daily basis. The interpretation was
that large comets or swarms of comets evaporated periodically as they
approached the star, causing a brief decrease in the light coming from
the star. The UC Berkeley team found the same signature with HD85905
and HR10.

This past April three other stars -- Vega, Fomalhaut and HR4796A --
made headlines when two separate groups of astronomers produced new
Hubble Space Telescope photos that seemed to show evidence of
proto-planets in the disks of dust around the stars.

"Much attention has recently been focused on detecting the infrared
signatures from disks of dust surrounding proto-planetary systems such
as Vega and HR4796," Crawford said. "Our new observations show the
presence of gas disks and comet-like bodies in these planetary building
sites. Although the inner planets in our own Solar System are made
mostly of rock, the outer planets like Jupiter and Saturn are gas
giants. Our new data show a potential reservoir of gaseous building
materials for such planets."

While Welsh acknowledges that the evidence for planets in formation
around the two stars is indirect, "there is no other mechanism that can
explain what we're seeing -- the data tell us there are numerous
asteroids and comets around these stars," he said.

==================
(5) THE IAU's EDGAR WILSON AWARD

From IAUC 6936
http://cfa-www.harvard.edu/iau/special/EdgarWilson.html

This is to announce the establishment of and the criteria for the Edgar
Wilson Award for the discovery of comets. The Award shall be allocated
annually among the amateur astronomers who, using amateur equipment, have
discovered one or more new comets. Only comets officially named for their
discoverers shall be included in the annual count. Since particular
recognition is to be given to the amateurs who discover the most comets,
identical fractions of the total Award funds shall be allocated for each
comet with an eligible discoverer, except that if the same comet is credited
to more than one independent eligible discoverer, each discoverer shall
receive a full fraction. If the discovery is made as the result of
information produced or prepared by some other person, it shall not qualify
for consideration. Eligible discoveries may be made by visual, photographic
or electronic means.

The Award shall be administered by the Smithsonian Astrophysical Observatory
(SAO), as the beneficiary under the Will of Edgar Wilson of Lexington, KY.
This administration shall specifically be through the International
Astronomical Union (IAU) Central Bureau for Astronomical Telegrams (CBAT),
which, with the advice of the Small Bodies Names Committee (SBNC) of IAU
Division III, has the responsibility for naming comets.

It is anticipated that the funds available for the first annual Award shall
be approximately US$20 000 (twenty thousand dollars). For the purpose of
this Award, a year shall be the period of twelve months beginning and ending
on June 11.0 UT. The first Award shall be for the year ending on 1999 June
11.0. The Award shall be announced and made during the month of July
following the end of each period.

To be eligible for the Award an individual must demonstrate:

  1. that he or she is acting in an amateur capacity, at least for the
     purpose of discovering the comet, and
  2. that only amateur, privately-owned equipment was used for the
     discovery.

In years when there are no eligible comet discoverers, the Award shall be
made instead to the amateur astronomer(s) judged by the CBAT to have made
the greatest contribution toward promoting an interest in the study of
comets.

SAO employees associated with the CBAT, SBNC members, as well as members of
their immediate families, are not eligible for the Award.

The Edgar Wilson Award is international in scope, and nationals of no
country are excluded from consideration. An observer who suspects he or she
has discovered a comet shall ensure that his or her discovery report reaches
the CBAT according to the usual procedures. The CBAT shall maintain the
necessary records and may contact the discoverers for eligibility
documentation.

The decision of SAO (via the CBAT) is final and takes precedence over the
description on this page.

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

Hypothetical Example

A rather contrived example shows most of the probable situations that can
arise. In the year 2028, there were 13 discoveries of new comets:

   * C/2028 C1 (Papathanassiou); professional with professional telescope
   * C/2028 F1 (Oldfield); amateur
   * P/2028 F2 (Lennon-McCartney); two independent amateurs
   * C/2028 G1 (Harrison-Starr); two amateurs working together
   * P/2028 K1 (SONOFLINEAR); professional
   * C/2028 L1 (Papathanassiou); naked-eye discovery by professional in an
     entirely amateur capacity
   * C/2028 M2 (Oldfield); amateur
   * P/2028 O1 (Hail-Caesar); independent amateur and professional discovery
   * C/2028 S2 (Jarre); amateur locating comet on Palomar Sky Survey V
   * C/2028 T1 (Harrison); amateur while observing with the 1.5-m at Palomar
   * P/2028 U1 (Harrison-Clapton); joint amateur and professional discovery
     with professional equipment
   * C/2028 U2 (Harrison-Clapton); joint amateur and professional discovery
     with amateur equipment in an entirely amateur capacity
   * C/2028 X3 (Starr); amateur

Comments:

   * In these examples the term 'amateur' alone means an amateur observing
     with amateur equipment. Similarly, 'professional' alone means a
     professional using professional equipment.
   * C/2028 G1 was by a team and is eligible for one share.
   * Although Papathanassiou is a professional, his discovery of C/2028 L1
     is eligible because it was not using professional equipment.
   * C/2028 O1: Hail is eligible because he is an amateur, Caesar is not
     because he is a professional.
   * C/2028 S2 is not eligible because the information used for the
     discovery was prepared by someone else.
   * P/2028 U1 is not eligible because the discovery was not made with
     amateur equipment.
   * C/2028 U2 was by a team and is eligible for one share.

The shares per discovery are then as follows:

            By comet                         By discoverer
C/2028 C1 (Papathanassiou)     0       Oldfield        2   = 1+1
C/2028 F1 (Oldfield)           1       Starr           1.5 = 0.5+1
P/2028 F2 (Lennon-McCartney)   1+1     McCartney       1   = 1
C/2028 G1 (Harrison-Starr)    0.5+0.5  Harrison        1   = 0.5+0+0+0.5
P/2028 K1 (SONOFLINEAR)        0       Lennon          1   = 1
C/2028 L1 (Papathanassiou)     1       Papathanassiou  1   = 0+1
C/2028 M2 (Oldfield)           1       Hail            1   = 1
P/2028 O1 (Hail-Caesar)        1+0     Clapton         0.5 = 0+0.5
C/2028 S2 (Jarre)              0       SONOFLINEAR     0   = 0
C/2028 T1 (Harrison)           0       Caesar          0   = 0
P/2028 U1 (Harrison-Clapton)   0+0     Jarre           0   = 0
C/2028 U2 (Harrison-Clapton)  0.5+0.5          Total   9
C/2028 X3 (Starr)              1
                     Total     9       Estimated Award per share
                                       = 20000/9 = c. US$ 2222

Just for interest's sake, if this award had been operating in recent years
the number of eligible discoveries would be: 1995 award, 5; 1996 award, 6;
1997 award, 5; and 1998 award, 4.

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*

MORE NUANCED AND CAREFUL EVALUATION OF EXTINCTION EVIDENCE IS DESIRABLE

From Timo Assmuth <Timo.Assmuth@vyh.fi>

Hello Benny and everybody entangled in the CCDigest network,

An inexact statement had slipped in the welcome letter of Clark Chapman
on 'Differences between civilization-threatening impacts and
extinction-level effects' (2nd June Digest) concerning the K/T
(Cretaceous-Tertiary) boundary events, in stating "virtually every
animal and plant (species) on the planet die(d)" (additions in
parentheses are mine, inserted to clarify the meaning of the quote).

In fact, browsing the paleontological literature on K/T boundary
events, e.g. the recent comprehensive critical review of the evidence
by A. Hallam and P.B. Wignall in 'Mass extinctions and their aftermath'
(Oxford UP 1997), the following pictures emerge - even with dinosaurs,
the debate continues of the temporal development of extinction (in
particular, rapidity, and occurrence before K/T). This is in part
related to the representativity and reliability of the fossil record.
Sceptics of the NEO impact-extinction hypothesis have also pointed out
e.g. the natural high generic turnover rate of dinosaurs, the areal
variation of species abundance, and pseudoextinctions.

- planktonic foraminifera (a key group in marine fossil records) do
seem to have suffered their all-time extinction peak around K/T
boundary. Yet, there is variation and uncertainty in how catastrophic
this was; some results suggest that ca. half the species vanished at
the boundary. Also, no sudden mass extinction has been found at high
paleolatitudes, which has been interpreted as suggesting high relative
sensitivity of the warm-climate taxa

- calcareous nanofossils did underwgo massive and rapid change, ca. 85%
vanishing at (within resolution) of K/T boundary

- in contrast to planktonic species, benthic foraminifera seem to have
suffered relatively little extinctions, which is consistent with a
scenario of environmental changes in shallow but not deep ocean waters

- also diatoms and dinoflagellates survived relatively well (perhaps
due  to resting stages)

- mollusc extinction before the end of Cretaceous is well-known, but
again its rapidity, globality and consistence across taxa aren't clear.
Recent high-resolution work indicates sudden extinction at (or within
sampling error range of) K/T impact event for some key groups such as
ammonites, while inoceramids seem to have suffered a more gradual
disappearance, perhaps globally.

- On continents, turtles and crocodiles fared well, which may reflect
the importance of the input of land-based detritus in these
(freshwater) environments (whereas the dramatic disappearance of marine
reptiles such as mosasaurs is consistent with a catastrophic
hypothesis) 

- a large share of birds also survived into the Tertiary, which is
somewhat surprising considering some of the postulated effects of the
Chicxulub impact

- also among terrestrial plants, extinction seems to have varied
considerably by taxonomic group (e.g., ferns, mosses and conifers
having fared better) and by region (e.g., Southern Hemisphere and
Europe exhibiting less change for some groups)

- for the extremely diverse insect faunas (studied little so far),
there are no indications of significant change across K/T boundary.

All in all, based on the groups studied, 70-76% of the species (with
genera-level and family-level observed extinction rates of 47 % and
16%, respectively) have been estimated to have vanished 'at the K/T
boundary'. However, as indicated above, the characteristics of this
development require more defining and scrutiny, e.g. relating its time
frame to the maximum temporal resolution of the strata.

The key question here is, then, how to summarize the evidence. Instead
of extinction of 'virtually all species' at the K/T boundary
(particularly when implying its occurrence rapidly), it would be better
to speak of the extinction of 'a majority of the species on the basis
of the groups studied' (perhaps within the temporal resolution of K/T
boundary).

The other (implicit) assumption in Clark's letter in this connection was
that the above changes resulted from NEO impact (at Chicxulub).
However, there are several alternative explanations also for rapid
('catastrophic') mass extinctions at the K/T boundary, including
volcanism, sea level regression, etc. These may or may not be causally
related to extraterrestrial agents - which may moreover include other
factors than (a single) NEO impact. It is possible and perhaps even
likely that the (multiattribute) extinction processes were
multifactorial, being the result of several causes. 

While on the subject, it may be reminded that for other mass extinction
effects there is still less clear evidence of an impact cause (despite
some recent supportive evidence).

Of course this was a minor point in Clark's letter, and quite
irrelevant to the core issue of distinguishing between differences in
effects. I wholly agree on this, and consider it one of the major needs
in developing risk assessments for NEOs. I also do agree on the need
for directing significantly increased resources to risk identification
(searches) and management (at some level, e.g. institutional).

Still, I wished to make these remarks because I think it important to
be specific and explicit, correct in details, and nuanced and balanced
- otherwise one risks e.g. accusations of 'overdoing' one's case. This
is particularly so with the K/T mass extinction, where inflation of the
evidence and too uncritical inferences are common. To be sceptical of
and careful with the 'dinosaur argument' is important also considering
its inherent appeal e.g. to lay people and media (cf. Deep Impact) -
which may be both used well and misused.

All the best,

10.6.98 Timo Assmuth
Finnish Environment Institute

Timo Assmuth
Dr.Sc. (environ.)
Special researcher
Finnish Environment Institute
P.O. Box 140
FIN-00251 Helsinki
Finland
tel. +358 9 40300 523
fax +358 9 40300 591
e-mail timo.assmuth@vyh.fi



CCCMENU CCC for 1998

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