PLEASE NOTE:
*
CCNet DIGEST, 8 June 1999
--------------------------
(1) 1998 OX4: THIRD ASTEROID WITH A NON-ZERO IMPACT PROBABILITY
FOUND -
SIMILAR OBJECTS EXPECTED TO BE DISCOVERED MORE
FREQUENTLY
Benny J Peiser <b.j.peiser@livjm.ac.uk>
(2) NEO SEARCHES REQUIRE FUNDING, COOPERATION
SpaceViews. The online Journal for Space
Exploration, 8 June 1999
(3) SPACEGUARD ONLY LOOKING ONE WAY
Spacer.Com, 2 June 1999
(4) FAST ROTATING ASTEROIDS
Petr Pravec <ppravec@asu.cas.cz>
(5) CLOSE-CALL ASTEROID COMING
Michael Paine <mpaine@tpgi.com.au>
(6) THE LARGEST IMPACT STRUCTURE IN FRANCE?
Andrew Glikson <geospectral@spirit.com.au>
(7) UK CHOSEN FOR FIRST LIVING PLANET MISSION
Peter Bond <100604.1111@compuserve.com>
(8) INTERNET REVEALS SOLAR EXPLOSION'S TARGET
BBC Online Network, 7 June 1999
(9) DISCOVERY OF EXTRATERRESTRIAL IRON AT THE TRIASSIC-PERMIAN
BOUNDARY
S. Miono et al., OSAKA CITY UNIVERSITY
(10) IS THERE A 100 KRY PERIODICITY IN THE ACCRETION OF
INTERPLANETARY DUST?
D.B. Patterson and K.A. Farley, CALTECH
(11) DICARBOXYLIC ACIDS IN K-T BOUNDARY SEDIMENTS
H. Mita et al., UNIVERSITY OF TSUKUBA
(12) ON THE EXTRATERRESTRIAL DELIVERY OF ORGANIC MATTER
V.A. Basiuk and J. Douda, UNIV NACL
AUTONOMA MEXICO
(13) PLAN TO DEMOCRATISE SCIENCE ONLINE
The New York Times, 8 June 1999
===========
(1) 1998 OX4: THIRD ASTEROID WITH A NON-ZERO IMPACT PROBABILITY
FOUND -
SIMILAR OBJECTS EXPECTED TO BE DISCOVERED MORE
FREQUENTLY
From Benny J Peiser <b.j.peiser@livjm.ac.uk>
As a result of recent discussions at the IMPACT workshop in
Turin, is
has become clear that the rapid increase in NEO discoveries,
which is
expected in the next decade, will inevitably lead to significant
numbers of PHAs with non-zero impact probabilities such as
asteroids
1997XF11 and 1999 AN10. In contrast to XF11 and AN10, however,
the vast
majority of these PHAs will no longer be newsworthy due to their
minuscule chances of actual impact (in the next century or so).
The
calculations of their orbital dynamics will be made routinely,
and
particularly interesting objects will be continuously monitored.
Consequently, public interest will only arise in exceptional
cases
which prove to have *significant* impact risks (< 1:1000?, or
in the
event of the detection of a Tunguska-sized object). That this
coolness is almost the norm already was evident when, at the last
day
of the IMPACT workshop, Andrea Milani presented new results he
and his
team (Steven Chesley and Giovanni Valsecchi) obtained from
calculating
the impact probabilities for asteroid 1998 OX4.
Asteroid 1998 OX4 was discovered by the SPACEWATCH search
programme
operated by the University of Arizona on Kitt Peak on July 26
1998.
Since this PHA (size c. 300-600m) approaches the Earth fairly
close
several times during the next 100 years or so, the Minor PLanet
Centre
has placed the NEO on its list of Potentially Hazardous Asteroids
<http://cfa-www.harvard.edu/iau/lists/Dangerous.html>
Andrea Milani and his colleagues have now analysed all dangerous
encounters asteroid 1998 OX4 will make with the Earth in the next
50
years and found that there is a tiny chance of an impact in
January
2046. Yet, the probability of such an encounter is, once again,
extremely small (1:100.000.000) and thus of actual interest only
to the
NEO search community which will have to monitor the object in the
future. Unfortunately, this PHA has been lost (which raises the
important questions of how to avoid such losses in the future!)
and
might only be recovered sometime in the year 2000 or 2004.
Andrea Milani tells me that the details of their calculations
will be
posted on the NEODys home page at http://newton.dm.unipi.it/neodys
in the next few days.
Benny J Peiser
==========
(2) NEO SEARCHES REQUIRE FUNDING, COOPERATION
From SpaceViews. The online Journal for Space Exploration, 8 June
1999
http://www.spaceviews.com/1999/06/08a.html
Astronomers involved in the search for near-Earth objects (NEOs)
stressed the need at an Italian conference last week for greater
funding and international cooperation to improve their searches.
Scientists attending the International Monitoring Programs for
Asteroid
and Comet Threat (IMPACT) conference in Torino, Italy,
representing a
large fraction of the NEO science community, worked on a number
of
recommendations to pass on to the International Astronomical
Union.
Key among the recommendations generated by scientists was the
need for
greater cooperation among the various national research programs
to
look for NEOs. Participants called for the creation of national
"Spaceguard" centers that would work together with the
international
Spaceguard Foundation to coordinate searches and follow-up
efforts.
Such cooperation is seen as necessary as the number of NEO search
programs grows. However, even with all the new programs, it is
uncertain whether they will be able to reach Spaceguard's goal of
detecting 90 percent of all NEO's more than 1 km (0.6 mi.) in
diameter
in the next ten years. In addition, followup observing programs,
as
well as efforts to observe smaller objects, will require more and
larger telescopes.
Participants also made recommendations on the best way to
communicate
reports of potentially hazardous objects, including the use of a
"hazard scale" to more effectively describe the risk of
impact by an
NEO. The specifics of those recommendations will be finalized
later
this summer.
Conference members also called on more efforts devoted to
followup
searches and compositional studies of asteroids to determine
their true
nature (although such studies will require the use of large
telescopes)
as well as new search programs based in the Southern Hemisphere.
The final recommendations from the IMPACT conference will be
passed on
to the IAU and published in July or August.
Copyright 1999, SpaceViews
===============
(3) SPACEGUARD ONLY LOOKING ONE WAY
From Spacer.Com, 2 June 1999
http://www.spacer.com/spacecast/news/oped-99f.html
By Dr. David James Johnson
Washington - June 2, 1999 - The U.S. Congress is considering a
boost in
NASA's budget for surveying the Near Earth Object population to
over 10
million dollars a year. Once approved, this would hopefully see
NASA
take a more receptive and responsible lead in this research.
Dr. David Morrison's recent statements on this potential funding
on
the CCNet, yet as he spoke of the Survey which NASA would
undertake
along with the USAF's LINEAR Project, there was no mention of the
southern hemisphere. When asked directly about this, Dr. Morrison
replied that the southern hemisphere had not been considered in
this.
FULL STORY at
http://www.spacer.com/spacecast/news/oped-99f.html
===============
(4) FAST ROTATING ASTEROIDS
From Petr Pravec <ppravec@asu.cas.cz>
Benny,
Reading a press release about the Mark Hammergren's work in the
June
7 issue of the CCNet Digest, I think that you and others could be
interested in my review talk on Fast Rotating Asteroids that I
will
give on the Asteroids, Comets, Meteors 1999 conference to be held
at
the Cornell University during July 26-30. See an abstract
of my talk
at the ACM99 abstract web page
http://scorpio.tn.cornell.edu/ACM/web_abs.html
(Although I am drawing your attention to my talk, I believe also
many
of the other abstracts on the page would be interesting for you
and
others.)
It was nice to meet you at the IMPACT workshop.
Best wishes,
Petr Pravec
Astronomical Institute
Ondrejov
Czech Republic
===============
(5) CLOSE-CALL ASTEROID COMING
From Michael Paine <mpaine@tpgi.com.au>
To: The Editor, Sky & Telescope
Your article "Close-call Asteroid Coming" has a factual
error. In
effect, it misquotes Paul Chodas from JPL. The article suggests
that
the odds of asteroid 1999 AN10 colliding with the earth in 2044
are
"...roughly 1 in 500,000 -- slightly more likely than a
chance hit
from an undiscovered asteroid over the next 40 years". The
odds of an
undiscovered asteroid with a diameter of 1 kilometre or more are
about 1 in 100,000 in any ONE YEAR. The odds over 40 years are
therefore about 1 in 2,500 - much more likely than the 1999 AN10
collision. A collision with a small "undiscovered"
asteroid is even
more likely. Assuming a poisson distribution, the odds of a
Tunguska
style event (60m diameter asteroid) are about 1 in 3 over a 40
years
period! See http://www1.tpgi.com.au/users/tps-seti/spacegd7.html
for
further details.
Michael Paine
NSW Coordinator
The Planetary Society Australian Volunteers
==============
(6) THE LARGEST IMPACT STRUCTURE IN FRANCE?
From Andrew Glikson <geospectral@spirit.com.au>
Dear Benny
CCNet 8.6.99 includes a report cited from "Sciences et
Avenir" of two
impact structures identified from Landsat images in southwest
France
- measuring 200-300 km in diameter and including (1)
Rochechourart
and (2) Bizeneuille.
A literature check suggests (1) Rochechouart is a 23
km-diameter
crater 214+/- Myr in age (based on R.A.F. Grieve's formal crater
listing and on Spray et al., 1998 - Evidence for a late Triassic
multiple impacts event on Earth, Nature, 392:171-173); (2) I have
not
found the reported crater Bizeneuille in the formal crater
listing.
Regarding the possibility that late Triassic impacts
(Rochechourart,
Saint Martin, Manicouagan, Redwing, Obolon) formed part of a
single
asteroid swarm, this was suggested by Spray et al. (1998) and
questioned by Melosh (1998 - Craters unchained, Nature,
394:221-222).
Yes, I will greatly appreciate being able to examine the reported
Landsat evidence for 200-300 km size craters in southwestern
France.
Andrew Glikson
8.6.1999
geospectral@spirit.com.au
=============
(7) UK CHOSEN FOR FIRST LIVING PLANET MISSION
From Peter Bond <100604.1111@compuserve.com>
ROYAL ASTRONOMICAL SOCIETY
PRESS INFORMATION NOTE
Date: 7 June 1999
Ref. PN 99/15
Issued by:
Peter Bond,
RAS Press Officer (Space Science)
10 Harrier Close,
Cranleigh,
Surrey, GU6 7BS,
United Kingdom.
Phone: +44 (0)1483-268672
Fax: +44 (0)1483-274047
E-mail: 100604.1111@compuserve.com
RAS Web: http://www.ras.org.uk/ras/
* * * * * * * * * * * * * * * * * * * * * * * * *
CONTACT FOR FURTHER INFORMATION ON THIS RELEASE:
Professor Duncan Wingham (University College London)
Tel: (+44) (0)171 419 3677
Fax: (+44) (0)171 419 3418
E-mail: djw@mssl.ucl.ac.uk
Patrick Edwards,
Head of Media Relations, (University College London)
Tel: (+44) (0)171-391-1621
Fax: (+44) (0)171-209-0117
E-mail: patrick.edwards@ucl.ac.uk
Ursula Edmunds, NERC Communications,
Swindon, Wilts.
Tel: (+44) (0)1793-411604
Fax: (+44) (0)1793-411510.
E-mail: uwe@nerc.ac.uk
* * * * * * * * * * * * * * * * * * * * * * * * * *
UK Chosen For First Living Planet Mission.
An innovative UK-led space mission to study the shrinkage of
Arctic
sea ice has been selected as the pioneering mission in the
European
Space Agencys new Living Planet programme. Known as CRYOSAT, the
mission was chosen ahead of 26 other proposals submitted from all
over Europe. The announcement was made by the UK Space Minister,
Lord
Sainsbury, who is currently chairman of the ESA Ministerial
Council,
and Antonio Rodota, ESAs Director General, at a press briefing
held
in London earlier today.
The 350 kg CRYOSAT, which is expected to be launched into a
near-polar
orbit in 2002, will be dedicated to a two year study of polar sea
ice. Lead scientist on the mission will be Professor Duncan
Wingham
of University College, London, who has spent many years studying
polar ice with radar satellites.
CRYOSATs radar will enable it to see in darkness and in all
weathers at
least 85% of the ice floating on the surface of the Arctic Ocean.
The
satellite will carry two radar altimeters, spaced one metre
apart, to
obtain high resolution synthetic aperture radar observations of
the
surface features as it passes overhead.
Even more significant, however, will be the use of a computer
processing
technique known as interferometry. This allows scientists to
combine
the radar signals which are bounced off the planets surface and
received by each instrument in order to create a
three-dimensional
view of the surface variations in the sea ice.
This technique will enable CRYOSAT to measure the thickness of
polar sea
ice. Although ice floes are typically 2 - 6 metres thick, only
10% of
his (20 - 60 cm) can be seen above sea level. The object of the
mission is to measure these differences in height, and so
determine
the thickness of the underlying ice. If the sea ice is melting
and
thinning, this should show up in the data returned by the
satellite.
We're interested in how much ice changes into water, said
Professor Wingham. We measure this to calculate the mass of
melted
ice entering the oceans.
Although Arctic sea ice has not so far been studied in detail, it
is
a particularly important factor in models of the global
environment -
much more so than Antarctic sea ice, which shrinks back to the
coasts every summer because it is much thinner and largely
restricted to inshore waters.
If the Arctic ice cap was to melt and disintegrate, the
consequences
could be catastrophic. With no ice to reflect sunlight and heat
in
the summer, the entire radiation balance of the Earth would
change.
This would lead to major shifts in ocean currents, particularly
in
the North Atlantic, leading to alterations in the thermo-haline
ocean
circulation system which transfers heat and minerals around the
planet. The end result would be dramatic global climate change
and
unpredictable disruption to the oceanic food chain.
NOTES FOR EDITORS.
CRYOSAT was selected as the first Earth Explorer opportunity
mission
under ESAs new Living Planet programme. It was chosen from 27
study
proposals which covered all aspects of Earth science, Earths
atmosphere, land surface, oceans and polar caps.
ESA has already selected a second candidate small-scale
opportunity
mission - known as Soil Moisture and Ocean Salinity. This
proposal is
led by French scientists, but has strong NERC involvement through
co-investigators at the Southampton Oceanography Centre and the
Institute of Hydrology. A decision about whether it will be
adopted
will be made when the funding situation has been clarified.
The Living Planet programme was given the go-ahead at a meeting
of
the ESA Ministerial Council in Brussels on 11-12 May. It will be
implemented in a series of five-year-long stages. The first stage
of
the programme (1999-2002) will be funded by ESA at a level
of 593
million Euro (about 400 million pounds). The UK has pledged a
contribution of 14% (approximately 67 million pounds) towards the
programme through the DTI and the Natural Environment Research
Council (NERC).
ESAs opportunity missions will be strictly budget limited with
the
agency committed to provide funding of no more than 80 million
Euro
(about 54 million pounds) towards each of the opportunity
missions.
Additional funding will be requested from other sources,
including
industry.
==============
(8) INTERNET REVEALS SOLAR EXPLOSION'S TARGET
From the BBC Online Network, 7 June 1999
http://news.bbc.co.uk/hi/english/sci/tech/newsid_363000/363358.stm
By BBC News Online Science Editor Dr David Whitehouse
A tremendous explosion took place on the surface of the Sun last
Tuesday and for a few very nervous hours astronomers did not know
whether it was heading for Earth.
The blast threw a jet of superheated plasma carrying magnetic
energy
into space at speeds of 1,000 kilometres per second (600 miles
per
second).
However, using the speed of the Internet, astronomers around the
world
rapidly compared images and decided that a worldwide alert was
unnecessary.
FULL STORY at
http://news.bbc.co.uk/hi/english/sci/tech/newsid_363000/363358.stm
===============
(9) DISCOVERY OF EXTRATERRESTRIAL IRON AT THE TRIASSIC-PERMIAN
BOUNDARY
S. Miono*), Y. Nakayama, K. Hanamoto: The discovery of native
iron
nuggets in the 250 my old bedded chert of Sasayama section,
Japan:
provenance estimated by PIXE analysis. NUCLEAR INSTRUMENTS &
METHODS
IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS
AND
ATOMS, 1999, Vol.150, No.1-4, pp.516-519
*) OSAKA CITY UNIVERSITY, SUMIYOSHI KU,OSAKA,JAPAN
A large number of micron sized native iron nuggets (micro iron
nugget)
occurs in the Triassic-Permian bedded chert. Judging from PIXE
analyses
and microscopic observations, an interstellar origin is deduced.
The
occurrence of micro iron nuggets is remarkable and is strongly
suggestive of the existence of a new accretional mechanism in
space.
(C) 1999 Elsevier Science B.V. All rights reserved.
================
(10) IS THERE A 100 KRY PERIODICITY IN THE ACCRETION OF
INTERPLANETARY DUST?
D.B. Patterson*) and K.A. Farley: Extraterrestrial He-3 in
seafloor
sediments: Evidence for correlated 100 kyr periodicity in the
accretion
rate of interplanetary dust, orbital parameters, and Quaternary
climate. GEOCHIMICA ET COSMOCHIMICA ACTA, 1998, Vol.62, No.23-24,
pp.3669-3682
*) CALTECH,DIV GEOL & PLANETARY SCI,PASADENA,CA,91125
We have determined the helium abundance and isotopic composition
of
seafloor carbonate sediments from the flanks of the Ontong Java
Plateau, western equatorial Pacific Ocean (ODP Site 806). These
results
provide a two million year record of the burial flux of
extraterrestrial He-3, which we believe is a proxy for the
terrestrial accretion rate of interplanetary dust particles. The
He-3
burial flux prior to similar to 700 ka was relatively low,
similar to
0.5 pcc cm(-2) kyr(-1), but from 700 ka to the present, the
burial
flux gradually increased to a value of similar to 1.0 pcc cm(-2)
kyr(-1). 100 kyr periodicity in the He-3 burial flux is apparent
over
the last 700 kyr and correlates with the oxygen isotope record of
global climate, with high He-3 burial fluxes associated with
interglacial periods. This periodicity and phase are consistent
with
previous He-3 measurements in North Atlantic sediments. Although
100
kyr periodicity in He-3 burial flux is in agreement with recent
predictions of the accretion rate of interplanetary dust based on
a
model of the orbital evolution of asteroidal debris, the
measurements
and predictions differ by one half cycle in phase. Nevertheless,
our
observations suggest the terrestrial accretion rate of
interplanetary
dust is controlled by orbital eccentricity and/or inclination
relative to the solar-system invariable plane. Such control is a
necessary but not sufficient condition for the hypothesis of
Muller
and MacDonald (1995) that variations in extraterrestrial dust
accretion modulates terrestrial climate with a 100 kyr period. We
also identify several brief (<25 kyr) intervals of strongly
enhanced
He-3 burial, possibly related to random and transient
fluctuations in
the accretion rate of asteroidal or cometary dust particles.
Copyright (C) 1998 Elsevier Science Ltd.
====================
(11) DICARBOXYLIC ACIDS IN K-T BOUNDARY SEDIMENTS
H. Mita*), N. Fukunaga, A. Shimoyama: Characterization of
dicarboxylic
acids in the Cretaceous/Tertiary boundary sediments at Kawaruppu,
Hokkaido, Japan, and comparison with those of carbonaceous
chondrites.
GEOCHIMICA ET COSMOCHIMICA ACTA, 1998, Vol.62, No.23-24,
pp.3695-3702
*) UNIVERSITY OF TSUKUBA,DEPT CHEM,TSUKUBA,IBARAKI 3058571,JAPAN
Twenty-seven C-2 to C-9 dicarboxylic acids were identified in the
Cretaceous/Tertiary (K/T) boundary sediments at Kawaruppu,
Hokkaido,
Japan. These dicarboxylic acids included normal, branched, and
unsaturated forms. Their concentrations were lowest (17, 0.40,
and
0.71 nmol g(-1) for normal, branched, and unsaturated,
respectively)
at the lowest horizon (0-0.8 cm) of the boundary claystone,
reflecting
the minimal biomass production due to the massive extinction of
organisms at the boundary. However, the concentrations were
higher at
the other horizons (0.8-13.7 cm) within the boundary claystone
than
above (40-495 cm) or below (-395-0 cm) it. In general, the normal
dicarboxylic acids showed a roughly logarithmic decrease in
concentration with increasing carbon number. Only methylsuccinic
acid
among the branched dicarboxylic acids could be shown to be
racemic,
because only in this case was enough material present in the
sediments
for analysis. Unsaturated dicarboxylic acids showed an apparent
cis-form predominance over trans with C-4 and C-5 isomers. The
logarithmic decrease, the presence of racemic methyl succinic
acid, and
the cis-form predominance can be explained as a result of the
65-million-year diagenesis of the sediments. These
characteristics were
compared with those found in the Murchison and Yamato-791198
carbonaceous chondrites (Shimoyama and Shigematsu, 1994) in order
to
seek evidence for a contribution of dicarboxylic acid(s) of
extraterrestrial origin to the K/T boundary sediments at
Kawaruppu;
however, the observed dicarboxylic acids in the sediments could
not be
attributed to an extraterrestrial origin. Copyright (C)
1998 Elsevier Science Ltd.
====================
(12) ON THE EXTRATERRESTRIAL DELIVERY OF ORGANIC MATTER
V.A. Basiuk*) and J. Douda: Pyrolysis of simple amino acids and
nucleobases: survivability limits and implications for
extra-terrestrial delivery. PLANETARY AND SPACE SCIENCE, 1999,
Vol.47, No.3-4, pp.577-584
*) UNIV NACL AUTONOMA MEXICO,LAB QUIM PLASMAS & ESTUDIOS
PLANETARIOS,INST CIENCIAS NUCL,MEXICO CITY 04510,DF,MEXICO
The idea of extraterrestrial delivery of organic matter to the
early
Earth is strongly supported by the detection of a large variety
of
organic compounds in the interstellar medium, comets: and
carbonaceous chondrites. Whether organic compounds essential for
the
emergence and evolution of life, particularly amino acids and
nucleic
acid bases found in the meteorites, can be efficiently delivered
by
other space bodies is unclear and depends primarily on capability
of
the biomolecules to survive high temperatures during atmospheric
deceleration and impacts to the terrestrial surface. In the
present
study we estimated survivability of simple amino acids glycine,
L-alanine, alpha-aminoisobutyric acid, L-valine and L-leucine),
purines (adenine and guanine) and pyrimidines (uracil and
cytosine)
under rapid heating to temperatures of 400-1000 degrees C under
N-2
or CO2 atmosphere. We have found that most of the compounds
studied
cannot survive the temperatures substantially higher than 700
degrees
C; however at 500-600 degrees C, the recovery can be at a percent
level (or even l0%-level for adenine: uracil, alanine, and
valine).
The final fate of amino acids and nucleobases during the
atmospheric
deceleration and surface impacts is discussed depending on such
factors as size of the space body, nature and altitude of the
heating, chemical composition of the space body and of the
atmosphere. (C) 1999 Elsevier Science Ltd. All rights reserved.
===============
(13) PLAN TO DEMOCRATISE SCIENCE ONLINE
From The New York Times, 8 June 1999
http://www.nytimes.com/library/national/science/060899sci-research-journal.html
N.I.H. Plan for Journal on the Web Draws Fire
By ROBERT PEAR
WASHINGTON -- The director of the National Institutes of Health
has
touched off a passionate debate by proposing that scientists
disclose
and disseminate the results of biomedical research on the
Internet,
making the full text of their reports available at no cost to
anyone
with a computer anywhere in the world.
The director, Dr. Harold E. Varmus, said his proposal for an
electronic
publishing operation, called E-biomed, would speed the progress
of
science by accelerating the exchange of information among
researchers
and by vastly increasing access to it.
Moreover, he said, the Web site could be "a democratizing
force"
because any legitimate researchers, "however remotely
located or poorly
known," could enter reports on it.
FULL STORY at
http://www.nytimes.com/library/national/science/060899sci-research-journal.html
----------------------------------------
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
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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
*
NEW IMPACT RISK PAGE
From Andrea Milani <milani@dm.unipi.it>
Dear Benny,
We have done as promised; you can go to the home page of NEODyS
http://newton.dm.unipi.it/neodys/
and from there you will find a link to an "Impact Risk
Page" (in the
What's new section). This page is currently maintained manually,
but we
are working towards an automated system.
We appreciate your comments, as well as comments by your readers,
on
how clear, understandable it is; the style has to be cool and
technical, but we are ready to change the wording if this can
increase
accessibility.
Yours
Andrea Milani and Steve Chesley
================================================
Andrea Milani
Dipartimento di Matematica
Via Buonarroti 2
56127 PISA ITALY
tel. +39-050-844254 fax +39-050-844224
E-mail: milani@dm.unipi.it
WWW: http://virmap.unipi.it/~milani/homemilani.html
================================================