Coughy Anan@united.nations.hq

    Duncan Steel <>

    Clark Chapman <>

    Ron Baalke <>


From: Coughy Anan@united.nations.hq

Dear NEO researchers

I am pleased to inform you that due to the recent events surrounding
asteroid 1997 XF11 the general assembly of the United Nations has today
decided in an unananimous vote to provide $ 500m in funds for setting up
a global system of NEO detection and R&D in NEO deflection for the next
10 years. Brothers and sisters, we are all convinced that this money
(most of which will come from the outstanding US subs, anyhow) is well
spent and will help to make the world a saver place. However, before
handing out the dosh, the nations of the world would like to call on
you to overcome you own discord and start joining forces.

In the hope that NEO researchers around the world will be just as
united and unanimous as we have always been, I remain

yours faithfully

Coughy Anan

UN Hq, New York, 1 April 1998


From: Duncan Steel <>

Dear Benny,

I note Rick Binzel's posting through the CC Digest, and also press reports
of the apparent agreement for coordination between various professionals
IN THE USA regarding possible press announcements (or indeed any mention
anywhere) about future situations where 'close' approaches to the Earth by
NEOs are predicted, and impacts cannot be ruled on on the basis of data in hand.

Unfortunately these attempts to control the dissemination of information
which is potentially (well, actually) alarming to the general populace are
doomed to failure.  Firstly, not all the professionals in NEO research work
in the USA, and so are controllable in this way (either through direct
pressure, funding considerations, and so on), and to keep this secret from
the WORLD's media through that avenue would require a black-out on the part
of the professionals world-wide.  Secondly, there are amateurs both in the
USA and elsewhere who are now capable of making the required calculations to
predict near-misses.  Many already had that capability (i.e., ephemeris
programs which are accurate enough for a few decades), but the announcement
through the CC Digest and elsewhere from Andrea Milani and colleagues of the
free availability through the WWW of the necessary software makes it likely
that the numbers of amateurs (and professionals) able to make the
calculations will now be growing significantly.  If anyone thinks that it
will be possible to keep all those people quiet, it is likely that they also
believe that Elvis Presley killed JFK (or vice-versa).

Not only is the software available to amateurs, note that much of the data
(NEO astrometry) derives from their efforts too.  Is there to be an attempt
to control access to NEO astrometry until after the appointed authorities
have decided to sound the all-clear?

Thus I'd like to make a prediction, as follows.  If this attempt to control
the availability to the media of stories like that of 1997 XF11 goes ahead,
through the implementation of whatever agreements between US professionals,
then what will happen is that an amateur somewhere will routinely run the
software on some very recent discovery, find a close approach in some
decades' time, tell his local friendly journalist, and then the story will
be picked up by the wires and the presses and phones will be running hot.
When it is realized that the news got out through, say, some amateur
astronomer living in Lapland, and that the data were available to various US
government instrumentalities (NASA, CfA, etc.), and that the information had
been deliberately suppressed, there will be a furore totally dwarfing that
over 1997 XF11.  With good cause.  To say the least this will diminish the
estimation of NASA (and others) in the eyes of the American public.  For
once the conspiracy theorists will have grounds for their beliefs: this
would be a conspiracy to keep people in the dark.  It will fail.

I write the above not to 'blame' anyone for recent events, or to support or
contradict the views of others about the desirability or otherwise of scares
such as that represented by 1997 XF11.  I am just saying that my belief is
that any such attempt by American professional astronomers to control the
outflow of information on this topic is virtually certain to fail, given the
present availability of NEO astrometry to all and sundry
(and if anyone tries to change that availability then the media will be onto
it in a flash).

Put simply, Pandora's Box is open. The best that can be done is to try
to direct the outflow from the box so as to achieve the least harm/most
good. You can't cram it all back in and shut the lid.


Duncan Steel


From: Clark Chapman <>


I have now written some material as a preface to my "Case Study" at

Excluding the first paragraph of the Preface (which deals with
the document itself), the remaining 7 or 8 paragraphs constitute
a "one-page-long" summary of my perspectives.


Preface. The following Case Study is a DRAFT. Since the last revision,
many colleagues have offered additional information and
corrections (which, I'm sorry to say, I have not yet had time to
incorporate), chiefly concerning the complicated circumstances
surrounding the 1997 XF11 asteroid impact scare of mid-March. The
detailed technical analysis of what several research groups did,
and how they communicated their results and opinions with each
other and with the media, is still not fully understood by me, nor
by anyone else. It will, however, be important to document it so
that better procedures can be developed that take account of the
"realities" that develop in circumstances like those in mid-March.
Certainly, with the rates of discovering NEO's increasing rapidly,
there will be future cases that the NEO scientific community will
have to face. Many are bound to have differences from the case of
1997 XF11, but the XF11 case typified many of the issues that I
expect to happen again.

My simplified view of the XF11 affair is this: There are roughly
2000 Earth-approaching asteroids that approach or exceed the "1
mile wide" size that David Morrison and I have established as
possibly civilization-threatening. Less than 10% of these have
been discovered. The job for NEO astronomers is to discover as
many of the remaining ones (NASA's stated goal, not yet
implemented, is 90% of them in the next decade), and to determine
their orbits. Almost certainly, as each one is discovered, it will
be demonstrated within days (occasionally as long as a few years)
to NOT be on a collision course with Earth. As we go through this
process of certifying that asteroids will NOT strike the Earth, we
will gradually reduce the probability of impact in the succeeding
30 years from the current 1 chance in 10,000 to 1 chance in
100,000 (from the remaining 10%).

As of March 11th, observations of the position of 1997 XF11 had
been reported to the IAU Minor Planet Center over a three-month
period. The good news is that those data, and those data alone,
were sufficient to demonstrate the 1997 XF11 would NOT hit the
Earth during its approach in 2028 or at any other time in the
foreseeable future (more specifically, that the chances of XF11
impacting the Earth could be shown to be MUCH less than the
background probability -- 1 chance in 10,000 -- of an unknown
asteroid hitting us before 2028).

But, instead of adding 1997 XF11 to the slowly growing list of
asteroids certified as not going to hit the Earth, the director of
the Minor Planet Center, Brian Marsden, instead made an
announcement to the world (via the IAU Circulars he edits and an
associated press statement) that the asteroid was "virtually
certain" to pass within 80% of the distance to the Moon and stood
a "small...not out of the question" possibility of hitting the
Earth. (It is not yet known, to me, whether Marsden's calculations
were faulty or rather that he misinterpreted them and/or used
ill-chosen words to convey his results.)

Because Marsden has a policy of holding onto the data he receives
from the world's astronomers, and of doing his own evaluation of
the data before making them available to other astronomers, nobody
else had the practical capability of making independent
calculations. Moreover, Marsden didn't bother to check his results
with colleagues at other institutions before making his faulty
announcement to the world. Within hours, Marsden was persuaded to
release the data, and within hours of that, several other
astronomers had correctly calculated that the probability of Earth
impact was essentially zero -- certainly much less than the
probability of impact from the as-yet-undiscovered asteroids.

Already during the evening of March 11th, several astronomers
requested that Marsden issue a public correction, and tell the
anxious world that new calculations by other astronomers showed
that the asteroid would not hit. He explicitly refused to do so.
Even by noon the following day, Marsden was still telling
reporters that the asteroid could hit. If no prediscovery
observations were ever located and no subsequent observations of
XF11 were ever made, a proper analysis of the Dec. 1997 - Mar.
1998 data -- done by several other astronomers within hours of
being provided the data by Marsden -- clearly places 1997 XF11 in
the "not dangerous" category.

Marsden finally, late on the 12th, changed his prediction to "no
impact", using as an excuse the arrival, and inclusion in his
calculations, of prediscovery data from 1990. It is essential to
realize, however, that this was "icing on the cake." Every other
expert on NEO's had already concluded that 1997 XF11 was in the
"safe" category long before the 1990 data became available.

In the future, it will be necessary for NEO scientists to do what
scientists have traditionally done for centuries, which is to have
important results peer-reviewed before they make rash
announcements to the public. To facilitate this, all data from the
international astronomical community should be disseminated as
rapidly as is technically possible, and procedures should be
implemented to cross-check and peer-review announcements of
potentially hazardous close approaches before such conclusions are
published (i.e. made public). This should be done rapidly. I
hasten to add that such a procedure is NOT "secretive" -- it is
the normal way that scientists report results and ensures that the
public can have some degree of confidence that the reported
results are reliable.

I hope to incorporate further corrections in my Case Study within
about a week, and I continue to solicit comments, suggestions,
corrections, etc.

Clark R. Chapman, 31 March 1998.


From: Ron Baalke <>

Royal Astronomical Society Press Notices

Date: 27 March 1998

Ref. PN 98/07 (NAM 4)

Issued by:

Dr Jacqueline Mitton
RAS Public Relations Officer
Phone: Cambridge ((0)1223) 564914
FAX: Cambridge ((0)1223) 572892


UK astronomers have discovered two of the faintest objects ever seen
orbiting our Sun. One is estimated to be 150 km (90 miles) across and the
other 110 km (70 miles). Both are about 45 times farther from the Sun than
Earth (4,200 million miles or 6,750 million km), and more remote than the
planet Pluto, which is currently 30 times farther from the Sun than Earth.
The objects belong to the so-called Kuiper Belt in the region of space
beyond the planet Neptune. Since 1992, 61 Kuiper Belt objects ('KBOs') have
been discovered, including 7 found by the same UK team. Most are over 200 km

But rather like the curious incident of the dog that famously did nothing in
the night-time [in the Memoirs of Sherlock Holmes] it is the fact that the
team DID NOT find more objects that may prove to be a highly significant
clue as astronomers probe the mysteries of these outer reaches of the solar
system. Based on present ideas about how Kuiper Belt objects formed,
astronomers expected to be finding these faint objects at even greater
distances. Since they did not, those ideas may need to be revised. It may be
that the average size of the KBOs is smaller the farther away they are, so
the most distant ones were too faint even for this survey. Or it might be
that the objects actually discovered mark the outer edge of the Kuiper Belt.

These latest results will be presented at the National Astronomy Meeting at
the University of St Andrews on Tuesday 31st March by Dr Alan Fitzsimmons of
Queen's University Belfast on behalf the team, which also includes Miss Edel
Fletcher (Queen's University of Belfast), Dr Mike Irwin (Royal Greenwich
Observatory) and Professor Iwan Williams (Queen Mary & Westfield College

Hardly any previous searches have been targeted on objects as faint and as
small as those the UK team were looking for when they made the observations
in November 1997. They used the 2.5-metre Isaac Newton Telescope on La Palma
to image the sky for 7 nights, searching a total area slightly smaller than
that covered by the full Moon. On the telescope they had a new, sensitive,
wide-field camera built by the Royal Greenwich Observatory. The new camera
can see five times as much sky as the one previously used.

During each night they stared continuously at different patches of sky for
up to four hours at a time. In each patch of sky several thousand distant
stars and galaxies could be seen. However even these images were not
sensitive enough to record the solar system objects the team were seeking.
So they combined the images by computer in a way that eliminated all stars,
galaxies and nearby asteroids and revealed only faint solar-system objects
at large distances from the Sun.

Two new objects were discovered. One is roughly 150 km in diameter, while
the other is only 110 km across. Both appear to be around 45 times further
from the Sun than the Earth. At this distance, the smallest object was forty
million times fainter than the faintest stars that can be seen by eye on a
dark night. They are so faint that it is not worth taking up all the
telescope time needed to track them in the future, and it is very unlikely
they will ever be seen again.


     Dr Alan Fitzsimmons
     Dept. of Pure & Applied Physics
     Queen's University of Belfast
     Belfast BT7 1NN
     Northern Ireland
     Tel: 01232-273124
     Fax: 01232-438918

Press room at the National Astronomy Meeting, University of St Andrews

     (8.30 - 18.00 Tue 31 March to Thur 2 April; 9.00 - 12.00 Fri 3 April):
     Phone: 01334-462168 and 01334-462169
     Fax: 01334-463130

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