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