CCNet 34/2002 - 14 March 2002

"Risk managers will have to think the unthinkable in the future -
that is another thing the terrorist attack of 11th September 2001 in
the United States has shown - and they will have to consider maximum
loss potentials that are albeit improbable but nevertheless possible.
Accordingly Munich Re's scientists devote a section in the new study to the
first in-depth investigation into the risk of meteorite crashes, of which
around 100 were documented last century. These crashes are capable
of causing a wide range of damaging effects. The study shows that the
effects of a "bombardment from space" are to be carried by the insurance
industry to a larger degree than has hitherto been assumed. This is because
meteorite crashes will probably lead to explosions and numerous fires,
which are covered in many insurance contracts nowadays."
--Munich Re, 13 March 2002

Benny J Peiser < >

Ron Baalke < >


Reiner M. Stoss, Starkenburg Observatory

Munich Re, 13 March 2002

inScight, 12 March 2002

Ron Baalke < >

Harvey Leifert < >

James Perry < >

(10) C/2002 C1 (IKEYA-ZHANG)
Mark Kidger < >


>From Benny J Peiser < >

On 12 March, exactly four years to the day after the first near earth
asteroid, 1997 XF11, was announced to have a non-zero impact probability,
NASA's Near-Earth Object Program Office launched their new SENTRY automatic
impact monitoring system (see info below).

The new SENTRY system is another big improvement in the way the NEO
community now routinely monitors and assesses potential (or virtual) impact
events. I congratulate the JPL team behind the new programme and wish them
all the best.

As CCNet readers are only too aware, the main problem with the handling of
virtual impactors has been due to shortcomings in the way such information
has been worded or publisised or both. In view of the new automatic
monitoring system, I hope that we will also adapt future risk communications
in accordance with lessons and experiences learnt from new discoveries and
past mistakes.

We have come a long way since 1997 XF11 and have learned over the last three
years that 'false alarms' are almost inevitable - just as they occasionally
occur in other disaster warning systems. Yet little of this progress would
have been made if the 1997 XF11 (and subsequent ateroid alarms) had never

At the same time as SENTRY was launched, another asteroid with a non-zero
impact probability was announced by the new programme. In fact, 2002 CU11 is
flagged up as a Torino Scale 1 object. However, since the cumulative Palermo
scale for 2002 CU11 remains negative, JPL abided by the rules and did not
request an IAU review.

2002 CU11 was discovered on 7 February and the observations currently extend
to 10 March. The arc is currently quite good, though not as good as 1997
XF11 and 1999 AN10 at the time of their Torino class 1-2 impact
possibilities in 2040 and 2044.

Both SENTRY and NEODys give an identical impact probability for 2002 CU11
(for 31 August 2049) of a 1 in 100,000 chance of impact. Nevertheless, while JPL's SENTRY website
has flagged up 2002 CU11 as a Torino Scale 1 object, the NEODYs RiskPage
does not mention this characteristic.

With SENTRY and the NEODys agreeing so well, there seems to be little need
for the IAU "technical" review process. There seems to be no reason to doubt
the accuracy of either the NEODys or SENTRY programmes. All that is
required, as far as I can see, is an assessment of whether or not any
official or public "statement" is warranted. At times, it might be much
wiser simply to add some further explanations and clarifications to the risk
pages so that the technical details of virtual impactors can be properly
understood by the average reader.

With regard to JPL's new programme and website, I would find it extremely
helpful if SENTRY could inform readers not only about the exact time an
object is found to have a non-zero impact probability; equally interesting
would be to know about future observational opportunities as well - and thus
the likely time during which the risk, most likely, will disappear). What is
more, by studying the chronological sequences and evolution of temporary
virtual impactors we may - perhaps - even learn something of interest.

Benny Peiser


>From Ron Baalke < >

NASA's Near-Earth Object Program Office ( ) announces
the arrival of the Sentry automatic impact monitoring system. In development
for nearly two years, Sentry is a highly automated, accurate, and robust
system for continually updating the orbits, future close Earth approaches,
and Earth impact probabilities for all Near-Earth Asteroids (NEAs).

When interpreting the Sentry Impact Risks Page
( ), where information on known potential NEA
impacts is posted, one must bear in mind that an Earth collision by a
sizable NEA is a very low probability event. Objects normally appear on the
Risks Page because their orbits can bring them close to the Earth's orbit
and the limited number of available observations do not yet allow their
trajectories to be well-enough defined. In such cases, there may be a wide
range of possible future paths that can be fit to the existing observations,
sometimes including a few that can intersect the Earth.

Whenever a newly discovered NEA is posted on the Sentry Impact Risks Page,
by far the most likely outcome is that the object will eventually be removed
as new observations become available, the object's orbit is improved, and
its future motion is more tightly constrained. As a result, several new NEAs
each month may be listed on the Sentry Impact Risks page, only to be removed
shortly afterwards. This is a normal process, completely expected. The
removal of an object from the Impact Risks page does not indicate that the
object's risk was evaluated mistakenly: the risk was real until additional
observations showed that it was not.

While completely independent, the Sentry system is meant to be complementary
to the NEODyS CLOMON impact monitoring system operated in Pisa, Italy.
Personnel from both the Sentry and NEODyS systems are in constant
communication, cross checking each other's results and providing
constructive feedback to continuously improve the efficiency, accuracy, and
robustness of both systems.

The Sentry system was developed largely by Drs. Steve Chesley and Alan
Chamberlin with significant technical help from Dr. Paul Chodas. Ron Baalke
provided our web site updates.

Donald K. Yeomans
Manager, NASA's Near-Earth Object Program Office
March 12, 2002


When interpreting the Sentry Impact Risk Page, where information on known
potential NEA impacts is posted, one must continually bear in mind that an
Earth collision by a sizable NEA is a very low probability event. Objects
normally appear on the Risk Page because their orbits can bring them close
to the Earth's orbit and the limited number of available observations do not
yet allow their orbits to be well-defined. In such cases there is a wide
variety of future orbits that can be fit to the existing observations,
sometimes including a few that can intersect the Earth. Whenever a recently
discovered NEA is posted to the Sentry Impact Risk Page, by far the most
likely outcome is that the object will eventually be removed as additional
observations are processed, the object's orbit is improved, and its future
motions are more tightly constrained. As a result, NEAs will routinely be
listed on, and removed from, the Sentry Impact Risk Page, sometimes
appearing only briefly. This is a normal ongoing process - completely
expected. Hence, the placement of objects upon the Impact Risk Page and
their subsequent removal therefrom do not indicate that an object was
mistakenly thought to be a risk. It was a risk - until additional
observations rendered it otherwise. On the other hand, the Impact Risk Page
lists a number of lost objects that are, for all practical purposes,
permanent residents of the Risk Page; their removal may depend upon a
serendipitous rediscovery.

Most visitors to this web site will be primarily interested in the table
presented on the Impact Risk Page. The rightmost two columns quantify the
risk posed by the tabulated objects, using both the Torino Scale, which was
designed primarily for public communication of impact risk, and the Palermo
Technical Scale, which was designed for technical comparisons of impact
risk. A Palermo Scale value less than zero and, in most cases, a Torino
Scale value of zero, indicate a risk below the so-called background level
(more info here), which is the average risk from the entire NEO population.
To date, the risks posed by the potential impacts identified by Sentry have
all been well below the background level, and hence, these events have been
of academic or professional interest only, and not deserving of great public
concern. Events with a Palermo Scale value greater than zero are expected to
be very rare, but if one should be predicted, a Technical Review of the
prediction would likely be requested from our colleagues in order to verify
the calculations before the prediction is placed on the Risk Page.

For each object listed on the main Risk Page there is a separate page
providing more detailed technical information, some of which is included
only to facilitate cross-checking among specialists involved in computing
these predictions. The computation of Earth impact probabilities for
near-Earth objects is a complex process requiring sophisticated mathematical
techniques. An abbreviated and simplified explanation of the entire
computation process is presented below and a Frequently Asked Questions page
is available. For those who wish a more in depth mathematical explanation of
this risk assessment process, please see the paper entitled Asteroid Close
Approaches: Analysis and Potential Impact Detection by A. Milani, S.R.
Chesley, P.W. Chodas, and G.B. Valsecchi (2002).


Every day, observations and orbit solutions for Near-Earth Asteroids (NEAs)
are received from the Minor Planet Center (MPC) in Cambridge, Massachusetts.
Once classified as an NEA, the asteroid is thereafter given automatic orbit
updates within our Sentry system. A new orbit solution for an NEA is
computed whenever new optical or radar observations for that object become
available. Some high-priority objects are observed daily, while other
objects go unobserved for days or weeks, even though they may still be
bright enough to be seen. Optical observations cease when an object recedes
from the Earth (becoming too faint to be seen even with moderate-size
telescopes), or when the object moves into the daytime sky. Similarly, radar
observations are possible only when the object is near enough to the Earth
for the echo of a radar bounce to be detected. Once all the observations for
an object have been collected, an orbit determination process is used to
find the orbit which best fits all the observations.

The orbit is defined by six parameters (called the orbital elements) at an
initial time (called the epoch). An object's orbit is constrained to follow
equations of motion which model the forces expected to be acting on that
object at any given time. These forces are primarily the gravitational
attraction of the Sun, the planets, the Earth's Moon, and the three largest
asteroids, Ceres, Pallas, and Vesta). Given the six orbital elements at the
epoch, the object's positions at other times are computed by a numerical
integration, or propagation, of the equations of motion. In particular, the
object's position is computed at all the observation times, and given the
position of the Earth and the observatory locations at those times, the
expected values of the observations themselves are computed (e.g., the right
ascension and declination positions at the observation time). The difference
between the computed value for the observation and the value actually
measured by the observer is called the observation residual. The orbit for
an object is determined using a process called differential correction ,
which iteratively adjusts the six orbital elements until the sum of squares
of all the observations residuals reaches a minimum value. The final result
of the orbit determination process is called the best-fit or nominal
solution. Note that the best-fit orbit will not fit all the observations
perfectly (i.e., the residuals will not all be zero), but it should fit all
the observations to within their expected accuracies (typically less than 1
arc-second for optical observations). Also note that when new observations
of the object become available, a new orbit solution must be determined in
order to fit the augmented observation set.

It is important to understand that an object's orbit is never known
perfectly. Although the nominal orbit solution fits the observations best,
slightly different orbits may still fit the observations to within their
expected accuracies. There is in fact a whole set orbits around the nominal
which will fit the observations acceptably well: these all lie within what
we call the uncertainty region about the nominal orbit. The 'true' orbit is
expected to lie somewhere within this region. As new observations of the
object are made, the uncertainty region becomes more tightly constrained and
the range of possible values for the orbital elements narrows. As a result,
objects which have been observed for decades will have highly constrained,
well known orbits, while newly discovered objects tracked for only a few
days or weeks, will have relatively poorly constrained, uncertain orbits.

Once the nominal orbit and its associated uncertainty region have been
determined, the object's motion is numerically propagated forward in time
for up to 100 years in order to determine its close approaches to the Earth.
These nominal orbit close approach predictions are tabulated in our Earth
Close Approach Tables along with other uncertainty-related information such
as the minimum possible close approach distance, and the impact probability.
The uncertainty-related parameters are computed by projecting the
uncertainty region from the epoch to the respective close approach times via
so-called linearized techniques. Since these techniques lose accuracy when
the uncertainties become large, we include only reasonably certain
predictions in our Close Approach Tables. As a result, close approaches may
be tabulated decades into the future for objects with well-known orbits, but
only a few months or years into the future for objects with poorly known
orbits. On the other hand, Sentry assesses the long-term possibilities of an
Earth impact for all objects whose orbits can bring them close to the Earth,
even those with poorly known orbits. To perform this risk analysis it uses
more sophisticated non-linear methods.


Non-linear analysis is required whenever the uncertainties in a close
approach prediction are large. The position uncertainty of an asteroid is
usually relatively small over the time span of the observations, but it
usually grows, or stretches, as the object's position is predicted farther
and farther into the future. This uncertainty growth is especially fast
along the track of the orbit. The evolution of uncertainties can be
understood using the notion of so-called virtual asteroids (VAs). Suppose
the uncertainty region around the nominal orbital solution is filled with a
swarm of thousands or tens of thousands of virtual asteroids, each having
slightly different orbital elements, but all fitting the observations
acceptably well. Only one of these virtual asteroids is real, but we don't
know which one, although the central, nominal orbit is most likely to be the
real one. The further a VA is from the nominal position within the swarm,
the less likely it is to represent the real asteroid. If the
three-dimensional positions of the VAs are plotted around the time of the
observations, the swarm will take the shape of an elongated ellipsoid.

When the VAs are all numerically integrated forward in time, their slightly
different positions in space allow each to undergo slightly different
gravitational nudges (perturbations) from the planets and other perturbers.
Over time, this swarm of virtual asteroids will spread out along the orbit
of the nominal orbit, demonstrating how the position uncertainty ellipsoid
surrounding the asteroid's nominal position evolves into a very elongated
tube centered on the asteroid's nominal orbit. Long-term orbital
extrapolations can cause the asteroid's position uncertainty tube to grow to
great lengths, even extending one or more times around the asteroid's entire
orbit, and close planetary encounters can cause the uncertainty region to
even double back on itself by folding. This type of numerical analysis,
whereby many orbits are propagated forward in time to represent a single
asteroid's position uncertainty region, is the basis of the non-linear
techniques used by Sentry.

In practice, the non-linear analysis is made computationally more efficient
if only virtual asteroids along the central axis of the asteroid's elongated
uncertainty region are integrated forward in time. The assumption is then
made that virtual asteroids along this "Line of Variations (LOV)" are
representative of the nearby off-axis portions of the uncertainty region.
The first step in the risk analysis is to numerically integrate the VAs on
the LOV forward in time, and detect close approaches to the Earth. When a
stream of consecutive VAs experience essentially the same close encounter,
an automatic search is conducted to find the virtual asteroid that passes
closest to the Earth. The motion of this particular virtual asteroid and its
own local uncertainty region is then analyzed using linear techniques to
determine if an impact is possible and, if so, to estimate the probability
of impact. For pathological cases where an asteroid's uncertainty region
folds back on itself (due to a previous close planetary encounter) or where
several complex streams of virtual asteroids are evident, a second form of
non-linear analysis may be undertaken. This technique, called Monte Carlo,
samples the complete uncertainty region at epoch, not just the central axis,
and uses a great many more virtual asteroids. Once again, all the VAs are
integrated forward to the time of a close Earth approach, and monitored for
possible impact. If, for example, a total of 100,000 virtual asteroids were
integrated forward and two of these VAs manage to collide with the Earth in
the year 2040 then the impact probability for the real asteroid in 2040
would be approximately 2/100,000, or 1/50,000.

As noted earlier, some of the entries on the individual object pages are
meant to rapidly communicate and characterize the automatically generated
results to colleagues for verification and, as such, they are not
necessarily of general interest. Nevertheless, an effort is made here to
clarify a few of the tabular entries on these pages. The particular
circumstances of an Earth close approach are studied in the target plane, a
plane defined as passing through the Earth's center and being perpendicular
to the incoming velocity vector of the NEA.

see graph at

If we assume a particular asteroid's position uncertainty region is a long
three-dimensional tube stretched along its orbit, then a projection onto the
target plane will reduce the uncertainty region to a two-dimensional strip
centered on the Line of Variations (LOV) and passing a certain Distance from
the Earth's center. If this Distance is less than 1 Earth radius then one of
the virtual asteroids is known as a virtual impactor since it can strike the
Earth. Sigma LOV is a measure of the deviation of the virtual impactor from
the position of the central, or nominal, virtual asteroid. In other words,
Sigma LOV is a measure of how well the impacting orbit fits the available
observations. It is equal to zero for the best-fitting (nominal) orbit while
orbits with values between -3 and +3 ("3-sigma") comprise about 99% of the
virtual asteroid swarm. The farther Sigma LOV is from zero, the less likely
the collision with Earth. Since the intersection of the uncertainty region
with the impact plane will form a narrow strip on the impact plane, three
times the Width of this region in Earth radii will include more than 99% of
the entire localized uncertainty region. Sigma Impact is computed from
(Distance - R_Earth)/Width and it too is a measure of the impact likelihood.
It has a value of zero when the LOV intersects the Earth and has increasing
values as the central axis of the uncertainty region moves away from the
Earth in the impact plane.


>From Reiner M. Stoss, Starkenburg Observatory


did you notice this article: Versicherungsstudie "Meteoriten-Risiko wird



>From Spiegel Online, 13 March 2002,1518,186881,00.html

Seit dem 11. September ängstigt sich die Versicherungsbranche vor weiteren
unerwarteten Milliarden-Zahlungen. Eine Studie warnt nun vor einer
unterschätzten Gefahr: vor Meteoriteneinschlägen, die eine ganze Großstadt
wie Mexiko City zerstören könnten.

München - Nach den Terroranschlägen müsse die Branche lernen, das Undenkbare
zu denken, fordert die Studie der Münchner Rück. Immerhin hat der 11.
September auch die Versicherer kalt erwischt. Milliarden-Zahlungen trugen
dazu bei, dass sich der Jahresgewinn der Allianz halbierte und bescherten
der Swiss Re den ersten Verlust seit 100 Jahren.

In der Studie Topics haben die Experten aus München die
"Elementarschadensereignisse" wie Stürme und Erbeben aus dem Jahr 2001
gezählt und ihre Kosten bilanziert. Zugleich versuchten sie zu ermitteln,
welche anderen Katastrophen die Versicherer in Zahlungsnöte bringen könnten.

Bombardement aus dem All

Erstmals werde in der Studie das Risiko von Meteoriteneinschlägen genauer
erfasst, so das Unternehmen. "Die Folgen eines Bombardements aus dem All"
seien "in stärkerem Maße von der Assekuranz zu tragen, als dies bisher
angenommen wird". Denn Meteoriteneinschläge würden Explosionen und Brände
nach sich ziehen, die heute von vielen Verträgen gedeckt seien.

Allein im letzten Jahrhundert seien hundert Meteoriteneinschläge
dokumentiert, heißt es weiter. Eine der bekanntesten Katastrophen sei der
Absturz eines 50 Meter großen Klumpens aus dem All in Sibirien im Sommer
1908. Dieses Geschoss explodierte damals einige Kilometer über der Erde und
erzeugte so eine Druckwelle, die eine Waldfläche von 2200 Quadratkilometer
niederwalzte - das entspricht der Fläche von Mexico City.

In Zukunft mehr Katastrophen - und stärkere

Auch die Risiken und Folgen anderer Naturkatastrophen würden nicht
angemessen eingeschätzt, betonen die Autoren. Die bisher teuersten
Naturkatastrophen, der Hurrikan "Andrew" (30 Milliarden Dollar Schaden) und
das Erdbeben in Northridge, USA (44 Milliarden Dollar Schaden) hätten noch
weitaus verheerendere Wirkungen haben können, wenn der Sturm nur eine
geringfügig andere Bahn eingeschlagen oder das Zentrum des Bebens an ein
einer anderen Stelle gelegen hätte. Selbst eine öffentlich kaum
wahrgenommene Hagelfront könne durch eine Verkettung ungünstiger Umstände
Milliarden-Schäden anrichten.

Die Folgerungen, die die Rückversicherung aus der Studie ziehen wird,
scheinen klar: Die Prämien, die Versicherer für das Abwälzen von Risiken
zahlen müssen, sollten erhöht werden. Dafür führt die Münchner Rück noch ein
weiteres Argument ins Feld: den Klimawandel. Weil Treibhausgase die Erde
erwärmten und das Kyoto-Protokoll diesen Trend selbst bei vollständiger
Umsetzung nicht stoppen werde, seien in Zukunft häufigere und intensivere
Naturkatastrophen zu befürchten.

Katastrophenkosten 2001 stark gestiegen

Die Kosten, die 2001 durch Naturkatastrophen entstanden, hätten um 20
Prozent über dem Vorjahresniveau gelegen, bilanziert die Studie. Insgesamt
beliefen sich die volkswirtschaftlichen Schäden der 700 dokumentierten
Katastrophen auf 36 Milliarden Dollar. Ein einziges zusätzliches
"Größtschadensereignis" hätte gereicht, die Branche vor eine gravierende
Bewährungsprobe zu stellen.

Als teuerste Naturkatastrophe des Jahres benennt die Studie den tropischen
Sturm "Allison", der im Juni den Süden der Vereinigten Staaten überzog und
Schäden von sechs Milliarden Dollar anrichtete. Versichert war davon
immerhin die Hälfte.

Copyright 2002, Spiegel Online


Munich Re, 13 March 2002

Natural catastrophe balance 2001: No new loss records all told, but
individual results dramatic, especially an earthquake in India aber
dramatisch / Again inordinate strain on insurance industry/ Underestimated
loss potentials: first detailed examination of meteorite impact as an
insurance risk/ Climate change - what are the consequences for the insurance

In the latest issue of its study "topics", which has just been published,
the Munich Reinsurance Company reports, as in the past, on the natural
catastrophes of the past year. Owing to the fact that risk managers will
generally have to rethink future loss potentials entirely in the light of
11th September 2001, this year's publication turns the spotlight on the
question of hitherto underestimated risks and unidentified loss potentials
and in this connection analyses the insurance risk emanating from, etwa
meteorites. Munich Re's experts have also reassessed the effects of climate
change and have devised more stringent underwriting requirements as a
result. - As to the statistical section of the study: 2001 emphatically
confirms the long-term trend that insured losses are increasing much more
sharply than economic losses.

The overall balance in 2001: Insured losses increase sharply

Altogether 700 natural hazard losses were recorded last year. At around US$
36bn economic losses were about 20% above the previous year's level (US$
30bn). Insured losses rose to US$ 11.5bn in 2001, thus increasing by more
than 50% compared with the previous year (US$ 7.5bn). A gigantic loss event
in the realm of natural catastrophes would have been a severe test on the
capacity of the global insurance industry in addition to the burden it has
to cope with from the devastating attack on the World Trade Center.

More than 25,.000 people were killed in natural catastrophes during 2001.
This large figure is mainly due to the series of strong earthquakes at the
beginning of the year. On 13th January an earthquake in El Salvador, which
had triggered innumerable landslides, claimed the lives of 845 peopleums.
The death toll from the major earthquake in Noch weitaus dramatischer war
dGujarat in the northwest of India on 26th January was above . Es 14.,000.
Immediately after the quake Munich Re sent its experts into the disaster
area, where the M 7.7 quake had destroyed tens of thousands of dwellings as
well as industrial and commercial buildings. The company also sie organized
an interdisciplinary conference in New Delhi, which took place around the
anniversary of the quake.. At this conference, future strategies on risk
management and possible insurance solutions were developed in collaboration
with Indian authorities and scientists.

Around the globe there were 80 quakes that caused losses in 2001, producing
economic losses of US$ 9bn and insured losses of about US$ 900m.

As in previous years, insurers' statistics were dominated by windstorms and
floods. These accounted for more than two-thirds of all events (480) and no
less than 92% of all insured losses. Tropical Storm Allison, which hit the
southern part of the United States in June, was the most expensive natural
catastrophe of the year, triggering an overall loss of US$ 6bn (more than
half of which was insured). The typhoon season was marked by numerous strong
storms. Typhoon Nari, which swept over Taiwan in September and caused major
damage in the capital, Taipei, generated an insured loss of US$ 600m.

Meteorites - an underestimated risk?

Risk managers will have to think the unthinkable in the future - that is
another thing the terrorist attack of 11th September 2001 in the United
States has shown - and they will have to consider maximum loss potentials
that are albeit improbable but nevertheless possible. Accordingly Munich
Re's scientists devote a section in the new study to the first in-depth
investigation into the risk of meteorite crashes, of which around 100 were
documented last century. These crashes are capable of causing a wide range
of damaging effects. One of the best known events involved a meteorite
measuring no more than about 50 metres which came down over Siberia on 30th
June 1908. The "projectile" exploded at a height of a few kilometres over
the Tunguska region; the pressure wave flattened about 2,200 km2 of forest
(equal to the area of Mexico City). The study shows that the effects of a
"bombardment from space" are to be carried by the insurance industry to a
larger degree than has hitherto been assumed. This is because meteorite
crashes will probably lead to explosions and numerous fires, which are
covered in many insurance contracts nowadays.

In connection with the reassessment of risks, the study looks again at
further loss potentials: The costliest natural catastrophes to date,
Hurricane Andrew (USA, 1992; economic losses: US$ 30b; insured losses: US$
17bn) and the Northridge earthquake (USA 1994; economic losses: US$ 44bn;
insured losses: US$ 15.3bn), could have been three times as expensive if a
few factors such as the track of the storm or the location of the hypocentre
had been slightly different. On account of the numerous complex chains of
cause and effect involved in natural catastrophes surprises and new loss
records must be reckoned with constantly. A single hailstorm in Kansas City,
for example, which received hardly any attention even among the US public,
caused a record loss of around US$ 2bn, of which about 70% was insured.

In order to minimize the overall risk, above all for insurers operating on a
worldwide scale, it is necessary to document as fully as possible the loss
scenarios that have been hitherto underestimated or unidentified.

Climate change as a risk of change

Not only loss events and loss factors but also gradual changes have been
under constant observation for years. Munich Re's scientists continue to
assume that climate and environmental changes have an increasing impact on
the statistics. Dr. Gerhard Berz, head of Munich Re's Geo Risks Research
Dept.: "Even allowing for a complete implementation of the Kyoto Protocol,
which will again be the subject of negotiations involving some 170 nations
this year, the emission of greenhouse gases will result in our having to
contend with the effects of climate change for decades to come, mainly in
the form of more frequent and more intensive natural catastrophes."

Dr. Wolf-Otto Bauer, member of the Board of Management of Munich Re: "The
reinsurers, which bear the lion's share of the losses from natural
catastrophes, must go on the assumption that the present underwriting
strategy will no longer be commensurate with the changes." In view of the
loss trends that can be observed, the conventional practice of retrospective
underwriting - which involves calculating premiums from the claims
development of the past - inevitably leads to premium adjustments lagging
behind and hence to losses increasing. The insurance industry must think
about how risk-commensurate fluctuation loadings can be calculated for the
risk of change inherent in climate change. Dr. Bauer: "The effects of
climate change make adequate prospective underwriting more essential than

topics 2001 (PDF format, 1,27 MB)


>From inScight, 12 March 2002

After astronauts lugged home piles of moon rocks, planetary scientists were
surprised to find that the enormous valleys on the moon's surface are all
nearly the same age. This prompted a controversial theory: that 4 billion
years ago, the adolescent Earth and moon were suddenly pelted by enormous
space rocks. Now two researchers argue these objects must have been
asteroids, not comets.

In the 1970s, data from moon rocks revealed that the moon's largest valleys,
or "basins," were formed between 3.88 billion and 4.05 billion years ago.
That implied that the moon and nearby Earth had suffered a torrential
bombardment of massive rocks. (Evidence of this on Earth has been
obliterated by the planet's geologic activity, which continually renews its
surface.) For decades, scientists have wondered how the other young planets
conspired to throw things at the Earth and moon. Some speculated that as the
outer planets formed or shifted orbits, they deflected a burst of both
comets and asteroids into the inner solar system.

But David Kring of the University of Arizona in Tucson and Barbara Cohen of
the University of Hawaii, Manoa, argue that the objects were asteroids
alone. They first compared moon rocks and bits of asteroids, and they found
that they contain similar concentrations of certain trace elements. Then
they tested whether the asteroid belt between Mars and Jupiter, the likely
culprit in an asteroid bombardment, was disrupted at the time. The pair
compared levels of key isotopes in asteroids that had fallen from the belt
and found that they were colliding about 4 billion years ago, suggesting
that some flew out of the belt then. Finally, they point out that a
meteorite found in Antarctica and originally blasted off the face of Mars
appears to have been partially melted by an impact at about the time Earth
and the moon were pelted. This bolsters the theory that the entire inner
solar system was blasted with asteroids when the moon's basins formed, the
researchers report in the February issue of Journal of Geophysical

But the asteroids-only interpretation isn't a sure thing, says Clark Chapman
of the Southwest Research Institute in Boulder, Colorado. The trace elements
in the moon rocks may have been deposited in smaller asteroid impacts after
comets formed the basins, he says. Meanwhile, William Hartmann of the
Planetary Science Institute in Tucson questions whether a bombardment--from
either comets or asteroids--happened at all. The moon's basins, he argues,
might all have the same age simply because before 4 billion years ago, the
still-forming moon suffered so many blows that the surface couldn't settle.


© 2001 The American Association for the Advancement of Science


>From Ron Baalke < >

Deadline Approaches for Next Round of Shoemaker NEO Grants
by Melanie Melton
Planetary Society
March 12, 2002

Those interested in applying for the The Planetary Society's next round of
Shoemaker Near Earth Object (NEO) grants have only three more weeks to do

Those amateur or professional astronomers interested in studying Near Earth
Objects can apply for the grant by filling out an application form and
sending it to The Planetary Society by March 31, 2002.

The application form can by found here:

The Shoemaker NEO grant program was established by the Society in 1997, in
an effort to advance the study of Near Earth Objects. Grant recipients in
the past have been both individuals and groups, amateur and professional
astronomers, all interested in studying asteroids and comets in Earth's

For this round of grants, the Society's international advisory group
reviewing the proposals will be considering three different categories:
Observation Programs, NEO Research Programs, and International Collaboration
in NEO Observations.

With several asteroid detection programs in place at major observatories
around the country, there has been a dramatic increase in asteroid detection
within the last year, creating a long list of objects in need of follow-up
observations. As a result, special consideration will be given to observers
interested in conducting follow-up NEO observations, especially those
capable of detecting objects fainter than magnitude V= 19.5 or so.

* For more information about the Shoemaker NEO Grant Program

* For NEO Grant Guidelines

* For the application form


>From Harvey Leifert < >

American Geophysical Union
12 March 2002
AGU Release No. 02-09
For Immediate Release

Contact: Harvey Leifert
(202) 777-7507

Martian Surface Features Were Eroded by Liquid Carbon
Dioxide, not Running Water, Researchers Say

WASHINGTON - Scientists have provided new evidence that liquid carbon
dioxide, not running water, may have been the primary cause of erosional
features such as gullies, valley networks, and channels that cover the
surface of Mars. Research suggesting that condensed carbon dioxide found in
Martian crust carved these features is reported by Kenneth L. Tanaka and
colleagues at the U.S. Geological Survey in Flagstaff, Arizona, and the
University of Melbourne, Australia, will appear this month in Geophysical
Research Letters, published by the American Geophysical Union.

Using Mars Orbiter Laser Altimeter (MOLA) data, Tanaka and his colleagues
constructed elevation profiles of the Hellas basin, which, at 2000
kilometers [1,240 miles] wide and nine kilometers
[six miles] deep, is the largest well-preserved impact basin on Mars. By
examination of digitally created elevation profiles with 500-meter [2,000
foot] resolution, they found that the volcanic
regions of Malea and Hesperia Plana, along the rim of the Hellas basin, are
several hundred meters [yards] lower than adjacent rim sectors.
Additionally, these areas lack the prominent triangular peaks, called
massifs, that are common in nearby areas.

Along the inner slopes of these regions, the researchers found, however,
evidence of old massifs covered by volcanic rocks. They are too low to be
covered, if there were volcanic activity today. The researchers suggest as
an explanation that prior to volcanic activity, these regions along the rim
of the basin resembled nearby areas, but were eroded to their present-day
elevations following the emplacement of the volcanic rocks.

Tanaka and his colleagues propose a "magmatic erosion model" to explain the
features of the volcanic areas of Malea and Hesperia Plana, suggesting that
they underwent catastrophic erosion
associated with explosive eruptions of molten rock. They suggest that liquid
in the Martian crust was heated when molten rock, or magma, rose to the
surface. As the liquid was heated, it expanded, until the pressure of
overlying material was too great, and an explosive eruption occurred,
shattering overlying rock, and causing it to move with the magma in an
erosive debris flow.

The authors believe that the fluid in the crust along this area of the rim
of the Hellas basin was mainly liquid carbon dioxide. A debris flow
dominated by carbon dioxide would flow faster and farther than a water-based
flow, they say. Also, carbon dioxide is more volatile than water at lower
temperatures, and the cold temperatures found on Mars would mean that less
carbon dioxide-based magma would be required to produce the observed erosion than magma
containing mainly water.

The researchers suggest that this mechanism of erosion can also explain
collapse features and channels elsewhere on Mars. They also note, however,
that their model is based on a variety of assumptions that must be further tested.

Notes for journalists:

The paper by Kenneth L. Tanaka, Jeffrey S. Kargel, David J.
MacKinnon, Trent M. Hare [Astrogeology Team, U.S. Geological
Survey], and Nick Hoffman [University of Melbourne],
"Catastrophic Erosion of Hellas Basin Rim on Mars Induced by
Magmatic Instrusion in Volatile-Rich Rocks," will be published
online within the next two weeks and later in the print edition of
Geophysical Research Letters. Its citation, which is to the online
version, is 10.1029/2001GL13885, 2002.

Journalists (only) may obtain a copy of the paper (11 pages) by pdf file or
by fax on request to Emily Crum at . Please indicate the format
desired and include your full name, name of publication, and your email
address or fax number. The paper and this press release are not embargoed.

The authors may be contacted as follows:
Kenneth L. Tanaka: +1 (928) 556-7208 or
Jeffrey S. Kargel: +1 (928) 556-7034 or
David. J. MacKinnon: +1 (928) 556-7162 or
Trent M. Hare: +1 (928) 556-7126 or
Nick Hoffman: +61 3 9479 1516 or



>From James Perry < >


There is a new RAND study entitled "Space Weapons Earth Wars" -- I think
CCNet readers will be interested in Appendix C ("Natural Meteoroids as

James Perry

(10) C/2002 C1 (IKEYA-ZHANG)

>From Mark Kidger < >


With more data available now and a better time base I have been looking more
closely at the light curve of Comet Ikeya-Zhang. According to the data that
I have at hand, the comet has been brightening rapidly since discovery,
although not as fast as has been suggested. Seichii Yoshida had found a
light curve solution of

m1 = 6.8 + 5 log Delta + 10 log r

which I used as my starting point. It gives a quite good fit to the data,
although it would make the comet a little too bright in early February. The
best fit that I obtain is

m1 = 7.2 + 5 log Delta + 11(+/-0.5) log r

This would give a peak of around magnitude 3.5 in the next few days,
consistent with the fact that the data that I am receiving from fairly
experienced observers still has the comet around magnitude 4.

The comet is brightening quite fast, but not as fast as has been suggested.
Certainly though, the light curve is typical of a rather gassy object. What
is interesting is that these rarely brighten fast close to the Sun. Images
show a tremendous amount of activity in the tail. This is a very spectacular
object in photographs and CCD images, even though visually the low altitude
and twilight robs it of part of its spectacle.

Readers can see the fit to the light curve and an extrapolation for the
future in:

I would expect the comet to fade faster after perihelion than it has
brightened, to the extrapolation may be slightly optimistic. Visibility
should still be reasonable into April, although this is never going to be a
very easy naked-eye object.


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