PLEASE NOTE:
*
CCNet DIGEST, 15 April 1999
---------------------------
QUOTES OF THE DAY
"It is potentially hazardous,
that's certain" (Paul Chodas)
"It's dangerous for centuries"
(Brian Marsden)
"All information will be openly
shared with astronomers and the
general public world-wide" (IAU
guidelines on reporting
potentially hazardous objects)
(1) ASTEROID'S PATH MAY BE DISASTROUS
Albuquerque Journal, April 14, 1999
(2) 40-YEAR ASTEROID WARNING: SCIENTISTS SAY ROCK COULD PASS NEAR
EARTH
ABC News
(3) UPDATE ON ASTEROID-STORY CONTROVERSY
EXPLOREZONE <rob@explorezone.com>
(4) CURRENT NASA GUIDELINES ON REPORTING OF POTENTIALLY HAZARDOUS
OBJECTS
http://impact.arc.nasa.gov/news/1998/apr/13.html
(5) CURRENT IAU GUIDELINES ON REPORTING OF POTENTIALLY HAZARDOUS
OBJECTS
http://www.iau.org/neo.html
(6) THE NAME'S BOND, JAMES BOND
BBC Online Network, 14 April 1999
=====================
(1) ASTEROID'S PATH MAY BE DISASTROUS
From Albuquerque Journal, Wednesday, April 14, 1999
http://www.abqjournal.com/scitech/1sci04-14.htm
By John Fleck
Journal Staff Writer
An asteroid discovered by New Mexico researchers in January could
hurtle perilously close to Earth in 2039, according to
calculations by
a team of astronomers in Italy.
Found with an Air Force-owned telescope near Socorro, the
asteroid
known as "1999 AN10" has jumped to the top of
scientists' list of
potentially dangerous asteroids.
The chances it could hit Earth in August 2039 are small --
preliminary
data put it at one in a billion, the Italian team calculated.
"This asteroid does not present an urgent situation,"
Steven R. Chesley
of the University of Pisa said in an e-mail Tuesday.
But the Italian researchers showed that 1999 AN10 will spend at
least
the next 600 years on an orbit that repeatedly crosses Earth's
path,
meaning that it remains a long-range danger.
"It's dangerous for centuries," said Brian Marsden, an
orbit expert
with the International Astronomical Union who keeps track of 1999
AN10
and objects like it.
"It is potentially hazardous, that's certain," said
Paul Chodas, a
research scientist in the Near Earth Object program at NASA's Jet
Propulsion Laboratory in Southern California.
Scientists at the Lincoln Near-Earth Asteroid Research project --
LINEAR -- spotted the half-mile diameter asteroid the night of
Jan. 13.
The telescope, at the northern end of White Sands Missile Range
near
Socorro, spends its nights scanning the sky for asteroids, and in
the
last year it has become the world leader in finding them.
Of the 64 most significant asteroids found by astronomers around
the
world since the beginning of 1998, 44 were found by LINEAR.
The LINEAR scientists notified Marsden, and he posted the
asteroid's
sky coordinates on the Internet so other astronomers could begin
watching it, gathering the data needed to determine its orbit.
Found in looping orbits around the sun far from Earth, asteroids
show
up in astronomers' images as faint dots of light. Only by
watching
night after night can scientists detect the motion that sets
asteroids
apart from faint stars.
It's painstaking work, but LINEAR has leapt to the front of the
pack by
using a powerful electronic telescope camera and sophisticated
computer
software that automates much of the task..
Most asteroids orbit innocuously far from Earth, but in recent
years
scientists have accelerated the discovery of potentially
dangerous
ones, the ones following cockeyed paths that cross Earth's orbit.
The chances are slim, but if Earth happens to be there when one
crosses
our orbit, the results could be disastrous, said Mark Boslough, a
Sandia National Laboratories scientist who has studied
asteroid-impact
scenarios.
An object the size of 1999 AN10 could kill living things over
large
areas and change Earth's climate, scientists say. The 1999 AN10
seemed
an unexceptional object when it was discovered, said Grant Stokes
of
the Massachusetts Institute of Technology's Lincoln Laboratory,
which
runs LINEAR.
Astronomers in Italy, Japan, Austria and Australia nevertheless
watched
1999 AN10 until Feb. 20, when it disappeared from view into the
daytime
sky as it neared the sun on its orbit.
The Italian group, led by Andrea Milani of the University of
Pisa, used
data from those observations to estimate the asteroid's future
orbit.
The group found it was likely to pass close to Earth in 2027, but
how
close is unclear. There's a remote chance that it will pass at
just the
right distance for Earth's gravity to deflect the asteroid onto a
path
that would then bring it back, 12 years later, to a cataclysmic
collision.
But uncertainties about the asteroid's distance from Earth in
2027 lead
to big uncertainties in the scientists' understanding of what
will
happen in 2039, because tiny differences in the tug it gets from
Earth's gravity in 2027 will make a huge difference later on.
"Small changes in the path of one close approach make big
changes in
the path in later close approaches," Chodas said. To narrow
their
conclusion, the scientists need more data, and they're eagerly
awaiting
further observations that will be possible when 1999 AN10 is
visible
again in June.
"That will tell us exactly what the circumstance in 2027
is," Marsden
predicted. "In a few months, when there is less uncertainty
in the
orbit, the picture will be very different from the one we have
now,"
Chesley said.
Copyright, 1999 Albuquerque Journal
=====================
(2) 40-YEAR ASTEROID WARNING: SCIENTISTS SAY ROCK COULD PASS NEAR
EARTH
From ABC News
http://abcnews.go.com/sections/science/DailyNews/asteroid990414.html
The Associated Press
S O C O R R O, N.M., April 14 An
asteroid discovered by New
Mexico researchers this year could come dangerously close to
Earth in
40 years, according to calculations by astronomers in Italy.
Asteroid 1999 AN10, located with an Air Force telescope near
Socorro,
thus moves to the top of sciences list of potentially
dangerous
asteroids.
The chances that it could hit Earth in August 2039 are only one
in a
billion, according to preliminary data, and "it does not
present an
urgent situation," said Steven R. Chesley of the University
of Pisa. He
reported on the asteroid via e-mail Tuesday.
But the Italian researchers showed that 1999 AN10 will spend at
least
the next 600 years on an orbit that repeatedly crosses Earths
path, so
it remains a long-range danger.
Regular Visitor
"Its dangerous for centuries," said Brian
Marsden, an orbit expert
with the International Astronomical Union. Paul Chodas, a
researcher
with the Near Earth Object program at NASAs Jet Propulsion
Laboratory
in Pasadena, Calif., agreed.
Scientists at the Lincoln Near-Earth Asteroid Research project,
or
LINEAR, spotted the half-mile-diameter asteroid Jan. 13 from
their
vantage point at the north end of White Sands Missile Range.
The LINEAR team notified Marsden, who posted the asteroids
coordinates
on the Internet so other astronomers could observe it.
Could Be a Big Bang
Although chances of collision are slim, scientists have said
that, if
there were a collision, an object the size of 1999 AN10 could
kill
living things over large areas of Earth and change the planets
climate.
The asteroid seemed unexceptional when discovered, said Grant
Stokes of
Massachusetts Institute of Technologys Lincoln Laboratory,
which runs
LINEAR.
But the Italian group led by Andrea Milani at Pisa calculated it
was
likely to pass close to Earth in 2027. They werent sure how
close. But
they said there was a remote chance it would pass at just the
right
distance for Earths gravity to deflect it onto a path that
could then
bring it back, 12 years later, for a cataclysmic collision.
But uncertainties about its distance from Earth in 2027 mean even
bigger uncertainties about 2039. Astronomers around the world
watched
the asteroid until it disappeared Feb. 20 in daytime skies as its
orbit
neared the sun. They await fresh observations in June. "That
will tell
us exactly what the circumstance in 2027 is," Marsden said.
Copyright 1999 The Associated Press.
=======================
(3) UPDATE ON ASTEROID-STORY CONTROVERSY
From EXPLOREZONE <rob@explorezone.com>
Yesterday, we told you about a group of scientists who posted a
paper
on the Web discussing a possible asteroid impact with Earth in
2039.
Our story, along with the newletter from Dr. Benny J. Peiser that
spawned the story, have both generated strong controversy and a
lively
defense from the researchers. Today, the story was picked up by
the BBC
and the Boston Globe (see below for URLs).
If you haven't already, you may wish to read the updated version
of our
story, posted yesterday afternoon, in which researcher Steven R.
Chesley responds to comments by Peiser regarding the publication
of the
research, which has yet to go through peer review. We believe
that the
issue of when and how to publish this type of research, which may
alarm
the public, is worthy of debate. We invite your comments.
http://explorezone.com/archives/99_04/13_asteroid_impact.htm
At the bottom of the story, as always, is a link explaining how
to make
Your Voice heard. (To get your comments posted with a story, you
can
always write directly to myvoice@explorezone.com.)
OTHER LINKS
BBC story
http://news.bbc.co.uk/hi/english/sci/tech/newsid_318000/318969.stm
Boston Globe story
http://www.boston.com/dailyglobe2/104/nation/Scientists_say_asteroid_may_tango_with_Earth+.shtml
OTHER NEWS
On a less controversial note, unrelated research groups studying
black
holes have come up with evidence that the massive objects come in
three
sizes instead of two, and that they may be more prevalent than
previously shown.
http://explorezone.com/archives/99_04/14_black_hole.htm
cheers,
Robert Roy Britt
Editor
explorezone.com
rob@explorezone.com
http://explorezone.com
=======================
(4) CURRENT NASA GUIDELINES ON REPORTING OF POTENTIALLY HAZARDOUS
OBJECTS
From http://impact.arc.nasa.gov/news/1998/apr/13.html
NASA Proposed Interim Roles and Responsibilities for NASA-funded
researchers on Reporting Potentially Hazardous Objects (PHOs)
1 April 1998
1. No hazard or threat prediction statements will be released
without
verification and consensus.
2. Astrometric data on Near-Earth Objects (NEOs) or suspected
NEOs
received by the Minor Planets Center (MPC) of the International
Astronomical Union at the Harvard-Smithsonian Center for
Astrophysics
will be made available to the scientific community, generally
within 24
hours of receipt.
3. Should a member of the NEO search community2) note a future,
possibly threatening, close approach to the Earth, the other
members of
the NEO search community will be notified so that calculations
can be
checked and archival files can be searched for prediscovery
observations. The response will be coordinated by a point of
contact to
be designated by the NASA Office of Space Science (OSS), and the
search community will make an effort to reach consensus as to the
nature
of the threat within 48 hours of being informed.
4. The NASA OSS will be informed at least 24 hours in advance of
any
public report of a PHO.
5. NASA, in coordination with appropriate national and
international
organizations, will sponsor a study of how best to communicate
NEO
issues to the public. This study will include an international
workshop to
develop detailed recommendations concerning procedures, roles,
and
responsibilities regarding observations, orbit calculations, and
communications with the public and policy-making officials.
1) These interim guidelines represent an agreement among
NASA-supported NEO searchers and dynamicists.
2) The NEO search community includes all major NEO searchers,
dynamicists, and data archivists.
=====================
(5) CURRENT IAU GUIDELINES ON REPORTING OF POTENTIALLY HAZARDOUS
OBJECTS
From http://www.iau.org/neo.html
IAU Policy Statement on Near Earth Objects
The Solar system contains a large number of bodies ranging in
size from
the major planets to tiny meteorites. Research over the last
several
decades has revealed that all major bodies of the Solar system
have
suffered larger or smaller impacts of bodies ranging in size from
millimetres to kilometres, the best-known example of which is the
abundance of craters on the Moon. Geological features on Earth
show
that impacts of significant size have occurred also on our own
planet.
The realization that such impacts occur at long, but presently
poorly-known intervals has recently caused growing concern in the
public, and in the press.
Research on the minor constituents of the Solar system - the
minor
planets or asteroids - has formed part of astronomical research
for the
last two centuries. The International Astronomical Union (IAU)
has
acted as the international focal point for this research since
the
foundation of the Union in 1919, in particular through its
Commission
on the Positions and Motions of Minor Planets, Planets, and
Satellites.
As part of this function, the IAU has for over 50 years operated
a
Minor Planet Center (MPC), currently at the Smithsonian
Astrophysical
Observatory (SAO; Cambridge, Mass., USA), for the collection of
data
and the dissemination of information concerning minor planets
and,
lately, comets. When continued research showed that the orbits of
several minor planets crossed that of the Earth, the IAU in 1991
appointed a Working Group (WG) on Near Earth Objects (NEO) to
coordinate international studies of NEOs and develop suitable
strategies for detection, follow-up, and orbit prediction. As one
result of this work, the international Spaceguard Foundation was
formed, and a number of observational programs for the detection
of
NEO's have been started. The WGNEO is also active in the
development of
proven algorithms for long-term NEO orbit prediction and thus for
assessing the distance to which NEOs may approach Earth within
the next
few centuries.
Currently, the number, size distribution, and orbits of
individual NEOs
are incompletely known from observation. Thus, the most urgent
task is
the detection and observation of NEO's to determine their orbits.
This
is an international responsibility that requires the efforts of
and
support for astronomers around the world. As the international
organization of professional astronomers, the IAU coordinates
this
activity through the NEO Working Group and offers the services of
the
MPC for the collection and collation of new observations and
computation of predictions from which follow-up observations can
be
made to improve our knowledge of the orbits and sizes of these
objects.
It is possible that, sometime in the future, these studies may
lead to
the prediction of an actual impact on Earth. In such a case, this
information must be promptly conveyed to the governments of the
world,
who may be in a position to organise countermeasures (a subject
outside
the mandate of the IAU). On the other hand, public announcements
of
potential impacts without proper verification are clearly
undesirable.
The IAU has therefore charged the WGNEO, in consultation with
astronomers worldwide, to draft a set of recommended procedures
to be
followed in case minor planets and comets are discovered that
lead to
predictions by the MPC of potential impacts. These procedures
will
conform to the following general principles:
1. All information will be openly shared with astronomers and the
general public world-wide.
2. The content of public statements that might alarm the public
will be
subject to prior scientific peer review by the IAU.
3. The IAU Officers and appropriate authorities will be consulted
before such information is released to the press.
The IAU reaffirms and increases its support of the Minor Planet
Center,
as the international clearing-house for this research, and
acknowledges
the support of SAO and NASA for its operation. The IAU encourages
all
countries of the world to contribute to the effort of charting
the NEO
population and will continue to ensure that this global issue is
addressed in a properly international forum.
========================
(6) THE NAME'S BOND, JAMES BOND
From the BBC Online Network, 14 April 1999
http://news.bbc.co.uk/hi/english/sci/tech/newsid_319000/319237.stm
By BBC News Online Science Editor Dr David Whitehouse
Czech astronomers have named a minor planet they discovered in
1983
after Her Majesty's Secret Agent 007 - James Bond.
Giving a minor planet a name is one of the privileges given to
those
astronomers who find them. Mostly, these objects are a few miles
across
and orbit the Sun in-between the orbits of Mars and Jupiter.
When a newly-discovered minor planet has been observed several
times,
and an orbit for it has been well established, it is given a
number.
At present, there are 10,448 numbered minor planets of which
7,000 have
been officially named.
According to Brian Marsden of the Minor Planet Center at Harvard
there
are rules about choosing names.
Naming rules
No military or political names are allowed until at least 100
years
after the event or death of the person concerned. No
unpronounceable
names or those that are obscene or in bad taste. None must be too
similar to existing names and none must be longer than 16
characters.
Following these guidelines, 223 minor planets have just received
names -
a record. They include asteroid 9007 which according to its
discoverers
at the Klet observatory in the Czech republic, could only be
called
James Bond.
Minor planets have also just been named after the writers Iris
Murdoch
and Arthur Ransome, as well as painters Constable, Holbein and
Gainsboroug.
Star gazing
There is also Minor Planet DENI which stands for the Department
for
Education in Northern Ireland.
But perhaps the most touching name given to a minor planet is
1992 QJ
Lewispearce. Lewis Percival Pearce was born at Nedlands, Western
Australia on 23 January this year. He suffered oxygen deprivation
during birth and never regained consciousness. Twelve days later,
he
died but not without sharing some experiences with his parents.
One of
them was observing the stars with his dad, Andrew Pearce.
Copyright 1999, BBC
----------------------------------------
THE CAMBRIDGE-CONFERENCE NETWORK (CCNet)
----------------------------------------
The CCNet is a scholarly electronic network. To
subscribe/unsubscribe,
please contact the moderator Benny J Peiser <b.j.peiser@livjm.ac.uk>.
Information circulated on this network is for scholarly and
educational use only. The attached information may not be copied
or
reproduced for any other purposes without prior permission of the
copyright holders. The fully indexed archive of the CCNet, from
February 1997 on, can be found at http://abob.libs.uga.edu/bobk/cccmenu.html
*
LETTERS TO THE MODERATOR, 15 April 1999
---------------------------------------
(1) 1999 AN10 FROM THE SCIENCE JOURNALIST'S PERSPECTIVE
Robert Roy Britt <rob@explorezone.com>
(2) NO SIMPLE ANSWERS
Keith Cowing <kcowing@reston.com>
(3) MANAGING THE KNOWLEGE OF HAZARDOUS ASTEROIDS
Michael Paine <mpaine@tpgi.com.au>
as posted on EXPLOREZONE, 15 April 1999
(4) PERSONAL APPRECIATION
Joy Warren <thewarrens@mediaone.net>
(5) CRYING WOLF
Martin Barstow <mab@star.le.ac.uk>
=========================
(1) 1999 AN10 FROM THE SCIENCE JOURNALIST'S PERSPECTIVE
From Robert Roy Britt <rob@explorezone.com>
Benny:
As Andrea Carusi, in his message to you, has struck a rather
accusative
tone toward this reporter (as did Steve Chesley in his initial
e-mails), I thought it might be instructive to recount the
communication that occurred in the early hours after your April
13
newsletter and before we reported the story on explorezone.com
later
that morning.
I received your e-mail, which discussed the publication of the
research by
Milani and his colleagues, at 8:01 a.m. (All times mentioned here
are
EST.) I e-mailed questions to Chesley and Giovanni Valsecchi at
9:14
a.m., and I sent one to Milani at 9:39 a.m.
I sent the questions to each researcher to insure at least one
would
see it. This seemed a reasonable gesture.
As a journalist, I've always found scientists to be helpful and
responsive. But since I don't work for AP or The New York Times,
I'm
used to getting no response from people who are on the defensive.
(I
should note that I am not the one who put them on the defensive,
but
rather was offering them a public forum in which to respond to
Dr.
Peiser's comments.)
By approximately 10:30 a.m. (I did not note the exact time) I
made the
judgement that the researchers likely were hoping I would go
away. It's
possible that they had not seen the e-mails yet, but Carusi's
comments
indicate they had. Carusi says that they did in fact choose to
"take
some time" in answering. It might have behooved them to let
me know
that. I would gladly have held my story for a reasonable period
while
they prepared a response.
The first e-mail I received was from Chesley, at 2:59 p.m., more
than 5
hours later. His answers were well-formed and lengthy, so surely
he had
been working on them awhile. I worked quickly to include his
comments
and had the revised version of the story up within an hour or so.
Carusi's comment, therefore, that "it is surprising the
arrogance of a
newspaperman pretending to be answered in a matter of
minutes" is a
misrepresentation of what happened.
It seems clear that the story, which has since been picked up by
AP and
other major news organizations, is legitimate. The dispute over
whether
the research should have been posted on the Web is a dispute
mostly
between scientists, but it has been made public, and that is news
in
this case (given that it involves a potentially deadly topic
matter).
In fact, the whole issue became public when it was posted on the
Web.
Any scientist who doesn't know this is far behind the general
public in
their understanding of the Web.
My only involvement in the whole affair is to have been the first
to
report the story, in the media, to the general public. In
retrospect, I
believe I acted fairly and honestly.
Sincerely,
Rob
----------------------------------------------
Robert Roy Britt
Editor
explorezone.com
rob@explorezone.com
http://explorezone.com
Science headlines by e-mail:
http://explorezone.com/ezhome/eznewsletter.htm
Free science graphics for your site:
http://explorezone.com/ezhome/ezgraphics.htm
=====================
(2) NO SIMPLE ANSWERS
From Keith Cowing <kcowing@reston.com>
Benny:
Looks like you have caused quite a stir - wire services and TV
networks
are featuring 1999 AN10 stories on their websites
..... I will let
you know if anything airs here in the US. ABC is usually watching
this
sort of thing closer than others.
Also - your distribution of all the responses pro & con-,
friendly &
angry, supportive & dismissive is admirable - something I
always try
and do as I cover issues on NASA Watch. No issue I've ever
thought
worth the bother of considering has ever evidenced a simple
answer.
Well Done!
Keith, fellow pot stirrer
=====================
(3) MANAGING THE KNOWLEGE OF HAZARDOUS ASTEROIDS
Michael Paine <mpaine@tpgi.com.au>
as posted on EXPLOREZONE, 15 April 1999
http://explorezone.com/news/opinion/1999/04_15_paine_asteroid.htm
By Michael Paine, News South Wales Coordinator,
The Planetary Society Australian Volunteers
E-mail: mpaine@tpgi.com.au
The current debate about Asteroid 1999 AN10 amongst astronomers
and
others in the scientific community is mainly concerned with the
manner
in which information about potentially hazardous asteroids is
released
to the public. This issue has received considerable attention
since
April 1998 when a "false alarm" was raised about
another asteroid (1997
XF11). A working group of the International Astronomical Union is
apparently preparing guidelines for announcement of possible
impacts
and the 1999 AN10 "incident" should help that group
review its work. As
a nonscientist who is trying, on a voluntary basis, to get a
major NEO
search effort re-established in Australia, I would like to offer
some
comments on this issue.
Firstly, I believe the common goal is to protect the Earth from
the
consequences of impacts by asteroids and comets. This involves:
a) detecting near earth objects
b) establishing the orbital parameters of newly detected
objects
c) predicting future orbits
d) identifying potential collisions with the Earth
e) verifying predictions of collisions to a high degree of
accuracy
f) implementing measures to avert or mitigate a collision
(including tsunami effects)
Items (a) to (d) are relatively low-cost, "routine"
activities that are
well described in the Spaceguard Proposal on NASA's Web site The
entire
cost of a ten year, worldwide Spaceguard Survey is about US$100
million
-- apparently equivalent to US military expenditure for just two
days
in the Balkan Conflict! Despite the low cost of this
"insurance for
mankind," efforts to introduce a worldwide Spaceguard Survey
appear to
have stalled -- advisors to government don't seem to take the
issue
seriously (in fact, I have questioned whether Spaceguard is too
cheap
for its own good). Several groups around the world have been
working on
this by lobbying politicians and key scientists. "False
alarms" don't
help this effort and also unfairly undermine the credibility of
scientists working in the field.
It turns out that the authors of the paper describing the
potential
hazard of Asteroid 1999 AN10 had submitted it for peer review
prior to
making a "preprint" available on the Internet. This is
entirely
appropriate -- the difficulty is deciding at what stage the media
should be informed and how such information should be worded in
order
to not raise undue alarm. Brian Marsden from the Minor Planet
Centre
has pointed out that 1999 AN10 was added to the list of
"Potentially
Hazardous Asteroids" on February 16, well before the Italian
paper was
posted on the Internet.
There are media relations precedents in other fields such as the
release of economic indicators -- everyone knows that the
statistics
are analysed by competent people over several weeks but that
public
release of the results will take place on a certain day. Another
(perhaps more relevant) analogy is where a medical doctor detects
a
potentially cancerous growth on a patient and sends a sample away
for
pathology tests. The patient is told that it will take a certain
time
(usually days) before the results of the tests are available.
My suggestion is that there be a similar "official"
delay in the
announcement of the results of NEO impact assessments. People
would
know that sufficient information had been gathered to enable
orbit
calculations to be undertaken, that one or more groups were
performing these calculations and that an announcement of the
results
would be issued (probably by MPC) on a certain day (say two
months
after its inclusion on the PHA list). As several people in the
NEO
field have pointed out, there really is no need for urgency in
the
release of these results.
A related issue is the need for consistency in terminology
amongst
spokesperson scientists when dealing with the press. Terms such
as
"potentially hazardous", "especially
dangerous" (Brian Marsden's
suggestion), "possible impact" and expressions of
probability need to
be clearly defined and some poorly understood terms need to be
avoided altogether. Richard Binzel's suggestion for a scale of
impact
hazards, similar to the Richter Scale for earthquakes, has merit.
Of
course, anyone commenting on an impact hazard issue should bear
in mind
the likelihood that some sections of the media will
sensationalise the
story.
A couple of other points:
The high orbital inclination of 1999 AN10 means we (humankind)
were
lucky to detect it in January this year with current (pitiful)
search
efforts. We are also lucky that its return between June and
August this
year should be observable -- the next opportunity is 2004! If, in
January, it had only appeared in southern skies then almost
certainly
it would have been missed - there is no southern NEO search
program
anywhere near the scale of those such as LINEAR in the northern
hemisphere (amateurs in Australia do a great but limited job).
The comparison of impact probabilities for 1999 AN10 with the
probability of an impact by an undiscovered object has a trap --
the
number of undiscovered NEOs (and therefore the probability of an
impact) will (hopefully) gradually reduce over the next few years
as
more objects are discovered! Also the point should be made that
the
probabilities are (I understand) for asteroids with a diameter of
1km
or more.
===============
(4) PERSONAL APPRECIATION
From Joy Warren <thewarrens@mediaone.net>
Dear Benny,
I have been on your CCNet mailing list for quite a while now -
you may
recall that I am a writer in Los Angeles. Recently, my
husband and I
became involved in setting up a web site for a nonprofit
organization
we are associated with. I must tell you, that after all the work
involved in getting this thing going I have come to appreciate
the work
you put in on CCNet by 1000 fold! Thank you.
Best regards, Joy
P.S. If you want to see our brand new nonprof web site -
check it out!
http://www.arts4peace.org
=====================
(5) CRYING WOLF
From Martin Barstow <mab@star.le.ac.uk>
Hi Benny,
Interesting debate going on about the latest asteroid
discovery/controversy. However, please forgive me if the story of
"The
boy who cried 'wolf'" increasingly springs to mind.
Cheers,
Martin
-----------------
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