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From Jonathan Tate (fr77@dial.pipex.com)
A "HOT DEBRIEF" ON THE WORKSHOP ON "INTERNATIONAL MONITORING PROGRAMS
FOR ASTEROID AND COMET THREAT" (IMPACT), HELD IN TORINO, ON JUNE 1-4,
1999
The Sponsors of the workshop were the IAU, ASI, NASA, ESA, Spaceguard
Foundation, IACG, The Planetary Society, Alenia Aerospazio - Divisione
Spazio and the Provincia di Torino.
This meeting was a follow up to the IAU WGNEO sponsored workshop on the
island of Vulcano (Italy) in September 1995, entitled "Beginning the
Spaceguard Survey". The aim of that workshop was to emphasise the need
for a co-ordinated effort, and to establish the basis for effective
international co-operation on the subject.
Participation at the Turin workshop included a high proportion of the
world expertise in NEO studies, and high ranking members of NASA, the
IAU and other sponsoring organisations.
The objectives of the workshop were:
- To encourage scientists in all nations and their sponsoring
agencies to increase NEO search and follow-up efforts.
- To improve communications among observers worldwide and to use
these improved communications to foster co-ordination of search and
follow-up activities.
- To assess the actual potential and limitations of ground-based
observing facilities, and to discuss the possible role of space-based
segments in NEO search.
- To develop procedures for assuring a rapid communication of
accurate information about Extremely Hazardous Objects which may be
detected in the future.
- To draft and discuss Recommendations to be distributed to the
scientific and political bodies able to support and fund NEO
researches.
The structure of meeting was to hold an initial plenary session during
which the conference was briefed on a number of topics, to bring
everyone fully up to date with recent developments. After the briefings
the conference split up into four sub-groups to discuss specific issues,
and to produce recommendations to be passed to the IAU. These
recommendations, once agreed by the sub-groups were then discussed at
another plenary session where they were agreed by the floor, or not.
While it is not yet possible to detail the recommendations that will be
passed to the IAU, as they have yet to be "word-smithed" by the
sub-group chairmen and agreed in their final forms, it is possible to
list a few of the significant statements made, discussions had and
recommendations made. So, below are some bullet points, to be followed
by a full report as soon as the results are published.
- Actual impacts are likely to be preceded by prior close approaches.
- Comets pose a much smaller risk than asteroids.
- Issues of funding and national interest need to be addressed.
- The issue of whether asteroids are rubble piles or solid bodies is
still unresolved. This information is very necessary for any
mitigation strategies. We need 4m-10m class telescopes to do
compositional studies on NEOs.
- Alan Harris of JPL estimated that about 18% of 1 km and above
sized NEOs have been discovered, but there are large population
uncertainties. However, we are still discovering asteroids at too
slow a rate (8-20 times).
- There are currently a number of space missions to asteroids and
comets. This is a "Golden Age" for studying comets and asteroids
according to Don Yeomans.
- NASA is increasing funds for NEO research, and has set up its
own US JPL program office.
- UK efforts need increased government interest. Recent events
have shown that there is official acceptance of seriousness of
problem. In the UK we have a wealth of experience, even in (eg) 4m
class telescopes. VISTA could be a wonderful tool.
- Japan is pressing ahead with its new NEO detection programme.
- There is an urgent need for some follow up programmes, and more
funding (staff) for the MPC. Ted Bowell proposed changes to the MPC
that were highly controversial, raising questions of control and IAU
international control. No consensus was reached.
- European possibilities were discussed eg DLR, ODAS, including
the use of ESO facilities.
- The number of inner Earth objects is thought to be similar to
the number of Atens. Both can be easy to find, provided that you look
at smaller solar elongations.
- Group 1 discussions emphasised the need for Southern Hemisphere
telescopes (economic and political).
- Group 2 discussions emphasised the need for research into NEO
physical characteristics.
- In Group 3 the importance of precoveries and plate log searches
was stressed. There was some emphasis on UKST archive. This would
also be an obvious role for the NSC. There was a strong
recommendation that analysis of PHAs should always be performed by at
least two independent groups.
- Group 4 developed a protocol, primarily for IAU purposes,
dealing with the announcement of PHOs. In the plenary session there
was some confused discussion, and eventually a shorter agreed
document was approved. This emphasised the need for individual
nations to discuss the issue; what do public, politicians and
decision makers require? The need for a National Spaceguard Centre is
obvious.
- R. Binzel discussed his new hazard scale, but J. Tate has
already produced something broadly acceptable for UK purposes. This
scale is designed for use when talking to the general public or the
media. D. Morrison observed that "people just don't understand
probability". S. Isobe reckoned that the index was a good lecturing
tool, but not good for communicating with the mass media.
Please be aware that this is a far from complete report, but I hope that
something of the workshop's flavour comes through.
Jay Tate
Spaceguard UK
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