CCNet, 24 November 1999


     "Then the Lord rained upon Sodom and upon Gomorrah brimstone and
     fire from the Lord out of heaven; And he overthrew those cities,
     and all the plain, and all the inhabitants of the cities, and that
     which grew upon the ground."
            -- Genesis 19:24-25

    David Dunham <>

    Explorezone, 23 November 1999

    Daniel Fischer <>

    NASA Science News <>

    Fox News, 22 November 1999

    Patrick Michel <>

    Michael Paine <>


From David Dunham <>

Pedro Valdes Sada reports two lunar flashes that he videorecorded near
Monterey, Mexico, about half an hour after the event seen by Brian
Cudnik and recorded by me that is now so famous.  He gives the times in
his message, copied below.  They are also on my tape, made in Mount
Airy, Maryland, at the times he gives!  Later today, we will digitize
these two new flashes and put them up at
They are also near the lunar equator. We will be determining the exact
times from the tapes when we can; I'm sure they will agree to within
the 1/15th or so second of timing that we can probably recover from the
tapes.  I had a WWV minute tone recorded at 5:07:00 UT, 7 and 8 minutes
before the flashes, respectively. The new objects are also probably
Leonids, since it was still near the time the peak was striking the
Moon, but of course we do not know for sure, since we don't know from
which direction the meteoroids approached the Moon.

For observers, a key to my success in this endeavor was the focal
reducing lens that I purchased from Orion; it decreased the f-ratio of
my 5-inch Schmidt-Cassegrain telescope from 10 to 6.3. That not only
increases the field of view by more than a factor of 3 in area, but
also increased sensitivity by concentrating the seeing disk of point
sources onto fewer pixels, and allowed, for example, recording
(faintly) the Earthlit dark side of the Moon.

By measuring images showing the lunar cusps and terminator taken before
and after the 4:46:15 UT event, I was able to determine that it
occurred at an angle (measured from the Moon's center, called "cusp
angle" in occultation terminology) of 77 deg. from the north cusp. 
Using also the distance of 1.7' in from the edge, this puts the
impact point in Oceanus Procellarum (Ocean of Storms) about 50 km
east-northeast of the center of the 50-km crater Cardanus, at
selenographic longitude 71 deg. W., latitude 14 deg. N., with estimated
accuracy of 2 deg. or 50 km.

David Dunham, IOTA, 1999 November 23
Date: Tue, 23 Nov 1999 03:00:33 -0600
From: Pedro Valdes Sada <>
To: Joan and David Dunham <>
CC: David Dunham <>
Subject: Re: Lunar impact seen & videorecorded; more records sought

    Hi David,

    I videotaped the non-illuminated side of the Moon for a while
before the leonid meteor radiant rose. There was some trouble while
doing it because I had allready committed myself to help with a large
number of people that attended a talk I gave that night on the subject
and then stayed for the meteor shower. So I had to keep an eye on the
camera and telescope at the same time I was answering questions and
talking with people.

    I checked my tape for the 4:46:15 UTC meteor crash on the Moon and
could not find it. I must have been aiming elsewhere. I am not sure
where because the FOV was too bright from the glare and I could not see
the limb. Another problem was that the portable telescope was not polar
alligned very well and I had to keep adjusting it every 5-10 minutes so
the Moon would not drift out of the FOV.

    At any rate, I have not checked all the tape, but managed to
identify two very suspicious-looking flashes that lasted at most 2-3
frames. They occurred at 5:14:13 and 5:15:20 UTC (+-1 second). Please
check your tape and pass it along to see if anyone else can confirm
them. The second one in particular, was right on the edge of my
camera's FOV. The first one I am pretty sure was real since the image
was a bit out of focus and looked very much like the stars I taped for
calibration after the Moon set (the focus must have drifted since it
was OK at the start of the night). I will try and digitize the two
frames involved. Unfortunately, on my VCR I can only freeze-frame the
second fainter one. There seems to be a brighter one in between frames
that I cannot freeze on the screen but can see momentarily. As for
location on the Moon of the possible impacts I cannot say for sure
since the Moon drifted constantly. I can say that it was near the
equator and close to the terminator since it drifted into the FOV
after a couple of minutes.

   Sorry that I cannot be more precise on the location and magnitudes.
I will try to grab the images involved and at least get a rough
estimate of the magnitude.


   Pedro Valdes Sada
   Univ. de Monterrey, Mexico


From Explorezone, 23 November 1999

By Robert Roy Britt,

The suggestion that comet Hale-Bopp might have a satellite orbiting its
nucleus, based on Hubble Space Telescope images, has resurfaced amid

Reporting in the current issue of Earth, Moon, and Planets, an
international journal, Zdenek Sekanina of the Jet Propulsion Laboratory
writes about a Hale-Bopp satellite detected by applying theoretical
modeling to images taken with Hubble's Wide Field Planetary Camera 2 on
five days during 1996.

If further research confirms the satellite, it would be the first known
cometary satellite discovered in a stable orbit, Sekanina said in a
telephone interview.

While other satellites have been spotted around other comets, they are
in each case drifting away from their host and destined to eventually
break free from the relatively minor gravitational tug. Hale-Bopp --
which made its closest approach to the sun in 1997 -- is a huge comet,
and Sekanina said it is therefore a prime candidate for being capable
of binding a satellite into a stable orbit. The satellite might have
broken off the main nucleus during a previous pass through the solar
system, he said, possibly because of the gravitational effects
of Jupiter.

Sekanina says the satellite is roughly 30 kilometers in diameter (18
miles), compared with a main nucleus estimated to be 70 kilometers
across (43 miles). The two objects appear to be separated by about 160
to 210 kilometers. The satellite appears to take two or three days to
complete an orbit, Sekanina said.


Harold Weaver, a research scientist in the Department of Physics and
Astronomy at the Johns Hopkins University, has doubts about the report,
which is based on Hubble Space Telescope (HST) images Weaver has
studied (and actually provided to Sekanina). In a separate paper due to
appear in an upcoming issue of Earth, Moon, and Planets, Weaver and a
colleague, Philippe Lamy, make their case against the possible

"We argue that Sekanina's conclusions about multiple nuclei cannot be
trusted because he is trying to extract more information from the HST
images than they contain," Weaver told "In particular,
the (detectors) on HST are not perfect devices, and one has to be very
careful about interpreting every 'bump and wiggle' in the data as
evidence for companion nuclei. In other words, we feel that Sekanina
may be overinterpreting the data."

Sekanina agrees with Weaver that the satellite (or second nucleus) does
not appear on the Hubble images. "I don't see it either," Sekanina
said. But while Weaver is an observer, Sekanina is a theorist. He
starts with the assumption that there is a satellite, then he tries to
find it in the data using a complicated modeling process that filters
the light reflected by dust surrounding the comet.

"The only way to extract the nuclei (from the images) is to do a
digital modeling of the central cloud," Sekanina said. He applied two
different techniques to five separate images. "I'm reasonably certain
that something is there," Sekanina said, "because I see it on each of
the five images using two different models of extraction of the dust

Weaver is familiar with the modeling method, and respects Sekanina's
work in general, but still he doubts that there is anything unusual in
the images. He noted that the new paper is similar to previous papers
by Sekanina that used similar methods to reach a similar conclusion.

"There are some interesting new results in the (new) paper … but, in my
opinion, they do not strengthen the case for multiple nuclei," Weaver
said. "Of course, we could be wrong."

Another group of researchers, writing in the September issue of
Astronomy & Astrophysics, claims evidence from ground-based
observations that indicates a second nucleus in Hale-Bopp. This
apparent second nucleus is a different one than that proposed by
Sekanina. It was derived by applying a technique called adaptive
optics, which attempts to filter effects of Earth's atmosphere and
resolve objects that otherwise are not apparent in an image.

Weaver and Lamy also dispute this detection, based on Hubble images
taken at nearly the same time but which do not show companions of the
type claimed by the authors, "even though they should have been easily
detected in the Hubble Space Telescope data."

Why does it matter?

Weaver said there are more than two dozen confirmed examples of comets
splitting into fragments, the most famous recent example being Comet
Shoemaker-Levy 9, which plowed into Jupiter in several stages. It is
therefore conceivable that relatively large fragments could have broken
away from Comet Hale-Bopp.

"However, no one has ever detected a bound companion to a cometary
nucleus, as Sekanina is claiming, so that would be very exciting,"
Weaver said. "There are now several known examples of binary asteroids,
and maybe comets sometimes also have stable companions."

If a comet had two nuclei, Weaver said there is a chance the two could
collide, "which would temporarily produce a large outburst in activity
by the comet."

Meanwhile, Sekanina plans to get to work figuring out the orbital
details of his suspected satellite. One result of that effort could be
a better understanding of comets in general. "If we can calculate the
orbit, we could calculate the first mass of a comet ever," he said. ez

Copyright 1999, Explorezone


From Daniel Fischer <>

Dear Benny,

I had the great luck of being able to observe the marvellous Leonids
storm from the Eastern Desert of Jordan - together with the two
scientists who had predicted the exact circumstances and got the timing
right: At

I have published a detailled report on the experience and also some of
the scientific questions raised by this first test of the
Asher-McNaught model. There could be even greater things on the




From NASA Science News <>

NASA Space Science News for November 23, 1999

Last week Thursday's Classroom invited students, parents, and educators
to watch the Leonid meteor shower and to submit their observations
for use in a future episode.  We've been deluged with hundreds of
reports. Congratulations to all the new meteor scientists out there! 
Because of the large volume of data we're recieved, we won't post these
observations until the December 9th episode on the upcoming Geminid
meteor shower.

Meanwhile, this week's episode -- "Leonids Rain in Spain" -- offers
some new meteoritic lesson plans based on the recent meteor storm.  If
you missed the sky show on November 18, you can recreate the event in
your classroom with "A Questionable Meteor Shower."  Other activities
include "Time Travel Postcards," "Interview with a meteorite," and
"Diamante Meteor Poems."



From Fox News, 22 November 1999

By Jonathan Leake , The Sunday Times

Sodom, the biblical world's most sinful city, is about to get its first
visitor since Lot left in haste as it was destroyed by heavenly fire
4,000 years ago.

A British researcher will this week venture to the bottom of the Dead
Sea — where Sodom's remains are thought to lie — in a mini-submarine.

Michael Sanders, a Leeds-born biblical scholar, has found what appears
to be the remains of the city under the surface of the Dead Sea by
studying satellite pictures taken by the National Aeronautics and Space
Administration (NASA). His findings have been backed by the Dead Sea
research unit from Tel Aviv University, whose scholars are on site with

"We are about to embark on our first dive. Finding the biblical city of
Sodom would be the greatest achievement of my life," he said last week.

The dives come just as the British Museum prepares to announce the
results of its research in the area, which appears to confirm that
Sodom was located there. A team excavating a Byzantine church has found
what is thought to be the legendary Cave of Lot hidden behind it.

According to the Bible, Lot and his daughters took refuge in a cave
while Sodom lay smouldering. It was there, thinking they were the last
people on Earth, that they decided to start a new generation.

To most people, including archaeologists, the biblical story of Lot,
Sodom and Gomorrah is metaphorical, a warning to sinful humans from the
authors of Genesis. No satisfactory archeological evidence of the five
lost cities of the plain, of which Sodom and Gomorrah were two, has
ever been unearthed.

Other scholars, however, including Sanders, believe Sodom and Gomorrah
not only existed but that they were also probably destroyed in a
catastrophe about 5,000 years ago and that their ruins were engulfed
beneath the salty waters of the Dead Sea.

Sanders's findings are supported by Dr. John Whitaker, a geologist at
the University of Leicester, who has found strong evidence of a
powerful earthquake in the area at that time.

He said in a research paper: "Their remains have not been found because
they are now under water. The total disappearance of the Vale of Siddim
and its cities beneath the lake would explain the lack of archeological
evidence. Further underwater exploration could be revealing."

Sanders believes the remains of the ancient cities are to be found off
the northwest shore of the Dead Sea, about 10 miles south of Jericho.

The orange Delta mini-submarine, on hire at a cost of almost 5,000
($8,000) a day, was the one used to explore the wreck of the Lusitania.

The 10ft-long, 6ft-high vessel was flown into Israel from California
last weekend. It holds two people and can stay submerged under hundreds
of feet of water for up to three days, but the team will be making only
short dives.

Sanders watched on Friday as the vessel was winched aboard a barge at
the Ein Gedi oasis in preparation for its journey to the northern

The Dead Sea may be only about 200 meters deep, but Sanders is diving
into murky diplomatic waters. The northwest corner of the sea is in the
West Bank, which was ruled by Jordan until the six-day war in 1967 and
has been under Israeli military occupation ever since. Now the
Palestinians have claimed it for their nascent independent state. The
expedition therefore had to be cleared with the Israeli army, the
Jordanians and the Palestinians — and if Sanders does find anything
down there, there will be a diplomatic battle over ownership.

Not everyone is as convinced as Sanders, however. Dr. David Neev, a
respected Israeli geologist, has dedicated much of his life to the
scientific study of the Dead Sea and its surroundings. He rejects
Sanders's thesis that Sodom and Gomorrah are lying at the bottom of the
northern end of the Dead Sea.

"The Bible is not always reliable in its chronology, but its
geographical descriptions have always turned out to be perfect.
According to the Bible the towns of Sodom and Gomorrah were located at
the south end of the Dead Sea, next to Mount Sedom and a long way from
Sanders's site," said Neev.

Copyright 1999, The Sunday Times


From Patrick Michel <>

Dear Benny,

Following the first annoucement of the School of Arc2000 (France) on
Singularities in Gravitational Systems and application to the chaotic
transport in the Solar System, we would very much like that the second
announcement (see below) which includes all the information of payment
procedure and a registration form appears in CCNet. Since the deadline
for registration is December 1st 1999, the sooner would be the better.
Thank you very much in advance.

Sincerely Yours,

Patrick MICHEL

Patrick Michel
Observatoire de la Cote d'Azur
UMR 6529 Cassini / CNRS            
B.P. 4229                           Tel: +33-4-92003055
06304 Nice cedex 4, France          Fax: +33-4-92003121

                            IN THE SOLAR SYSTEM

                           MARCH 12-18, 2000

                          ARC 2000 (FRENCH ALPS)


Dear Colleague,

Following the first announcement of a Winter School on the topic:
"Singularities in gravitational systems - Application to the chaotic
transport in the Solar System", which will take place at Arc 2000
(French Alps, France) on March 12-18, 2000, please find at the end of
the present message the registration form to be filled and sent via
Email to and, BEFORE DECEMBER 1,
1999. A cheque of Guarantee must also be sent (see further) before this

After recalling the motivations and the program of lectures, improved
in its mathematical part, we give the necessary details concerning the
cost and mode of payment. A Web page is now opened on the site of
the Observatoire de la Cote d'Azur (, go to Vie
Scientifique). Recall finally that this School is opened to a limited
number of people and we recommand to return the form and the cheque of
guarantee as fast as possible. A third announcement will then follow in
the beginning of next year for the participants, which will give all
the other details (logisitic, ....).


Directors of the School:


Observatoire de la Cote d'Azur
UMR 6529 Cassini
B.P. 4229
06304 Nice Cedex 4


OBJECTIVES: to provide a deeper knowledge to researchers working in the
different fields of dynamics and even of plasma physics on topics which
have undergone parallel and certainly complementary developments, among
communities which have a few occasions to meet, essentially
mathematicians of dynamical systems and physicists in dynamical fields,
familiar with numerical tools.

MOTIVATIONS: The theory of chaos plays a major role in various domains,
not only in modern physics (e.g., celestial mechanics, fluid mechanics,
solid state physics, ...) but also in other branches of knowledge such
as biology and economics. Major results have been obtained specially in
astronomy and gravitational systems.

A first kind of chaos due to the interaction between different types of
resonances (mean motion and secular), refered as "weak chaos", has been
detected in the motion of terrestrial planets of our Solar System by
Jacques Laskar; theoricists in the 60s had already discovered this kind
of chaos and the presence of invariant tori in hamiltonian system with
small perturbations (KAM theorem).

Another source of chaos exists and does not involve the interaction
between resonances. However, it is also responsible for the fast
transport as well as for the diffusion outside the Solar System of
small bodies such as comets and potentially dangerous asteroids
(Near-Earth asteroids). The sources of this kind of chaos are planetary
close approaches, and this is the main topic of the school.

The objectives and organization of the school are thus:

- To provide a clear introduction to mathematical methods as well as a
state of the art on the theory of singularities in gravitational
systems. One third of the school will be devoted to this aspect.
Lectures will be presented by mathematicians and physicists who are
used to numerical tools.

  The second part of the school will be devoted to the modelisation
and to the construction of mappings in which delta functions are used
to simulate close approaches as "shocks".

  The third part will present the state of the art on the diffusion of
comets, asteroids, meteroids and planetary rings. The application of
the knowledge on close approaches (singularities) to the determination
of spacecraft's trajectories, like Cassini, will also be presented.
  Since, the gravitational forces are not the only forces which have a
denominator proportional to the square of the distance, the community
working on plasma physics may also be interested in this school.

- Between the proposed lectures, a certain number of short
communications on the topic will be presented mainly by young


                       COST AND PAYMENT PROCEDURE

As usual, the "Formation Permanente" will take care of the cost of the
Hotel room and the registration fees of CNRS researchers. Travel
expenses will be paid only for CNRS researchers belonging to the
Regional Delegation 20 (Sophia-Antipolis). Other CNRS researchers must
ask the refund of their travel expenses to the "formation permanente"
of their own Delegation.

Then, if our finances allow it, we will also totally (or at least
partially) take care of the Hotel room expenses of our french
colleagues of the "Enseignement Superieure" as well as those of some
french PHD students. They may then ask to their own laboratories for
the refund of their travel expenses. 

NB: A possible partial or total refund by the School will be effective
only if the persons stay for the integrality of the School.

We give below the necessary information concerning the payment procedure
corresponding to the different situations.

1- CNRS researchers must send a cheque of guarantee for 500 French
Francs (order: ADION) at the address given below. It will be given back
to them at the School. The formation takes care of the registration

2- French citizens non CNRS researchers must send a cheque of guarantee
for 500 French Francs (order: ADION) at the address given below. It
will be given back to them at the School in exchange for registration
payments of 300 French Francs.

3- Non French citizens must send a cheque of guarantee of 500 French
Francs  (order: ADION) at the address given below, possibly converted
in their own currency or better in Euro or US $. It will be given back
to them at the School in exchange for registration payments of 300
French Francs. The Hotel room cannot be paid by the Formation. The
price is 2430 French Francs per person (full board for 6 nights) on the
basis of a double room, and 3060 French Francs for a single room
(limited number). Hotel rooms will have to be paid during the School,
directly at the Hotel, in cash or by credit card.

4- For accompanying persons who do not follow the School, only the payment
of the room will be required (no registration fees).

IMPORTANT: given the low rate with respect to the location and standing
of the  Hotel, NO MONEY SUPPORT can be provided to attend the School.

DEADLINE: DECEMBER 1, 1999. Late people will take the risk that no
place is left. The cheque of guarantee to ADION as well as the
registration form given below (to be sent also by Email as to and must be sent to the following

Patrick MICHEL
Observatoire de la Cote d'Azur
UMR6529 Cassini / CNRS
B.P. 4229
06304 Nice Cedex 4, France

Tel: +33 4 92 00 30 55
Fax: +33 4 93 26 55 80


                          PROGRAM OF LECTURES

                    (All lectures will be presented in English)

Lectures will be presented from 8:30 to 12:00 and from 17:00 to 20:00.
Free time can be devoted to physical and/or intellectual activities.

Alessandra CELLETTI (4h):

"Classical Results on Collisions and the Levi-Civita Transformation"
The Levi-Civita and KS transformations; Regularization by
inversion in velocity space; Birkhoff's transformation;
Perturbation theories.

Joerg WALDVOGEL (4h):

"Triple Collision and Close Triple Encounters"
Painleve's theorem and Sundman's theorem; triple collision and
Siegel's series; close triple encounters; McGehee's
triple-collision manifold.

Yves ELSKENS (3h):

"Dynamical and Kinetic Aspects of Collisions"
Hard collisions and hyperbolic dynamics; Statistics: few-body
problem and chaos; Many-body viewpoint: kinetic theory, H-theorem;
Elastic and inelastic collisions.

In addition, two seminars by Gabriella DELLA PENNA and Corrado
FALCOLINI are already scheduled on regularizing transformations.

Giovanni VALSECCHI (4h):

Close planetary approaches; semi-analytical models; application
to the dynamics of meteoroids.

Andrea MILANI (4h):

Close planetary approaches; numerical tools; transitory proper
orbital elements for Near-Earth asteroids.

Jean-Marc PETIT (3h):

Modelisation of the dynamics of planetary rings; chaotic diffusion.

Hans RICKMAN (3h):

Dynamics of long period comets; origin and diffusion through
the solar system;
The problem of short-period comets: from the Edgeworth-Kuiper belt
to the Jupiter family; Monte-Carlo models and Markov process.

Yves LANGEVIN (2h):

Planetary transfer of space probes.

3 hours of communications will be added to these lectures.


                          REGISTRATION FORM


- Firstname:

- Nationality:

- Professional Address:

- Prof. Tel. / Fax:

- Email:

- Personnal Tel. (or person to contact in case):

- Function and Position : () CNRS from the Regional Delegation 20

                          () CNRS from another Regional Delegation

                          () MENRT (French Ministry of Education)

                          () Student

                          () PHD Student

                          () Post-doc : date of defense of the thesis:

                          () Other :

- Field of Research (Astronomy, Geophysics, Chemistry, Biology,

- Research Topic(s):

() Double room with 2 beds: to be shared with Mr/Mme

() Single room (limited number)
    Extra-charge: 630 French Francs
    (paid by the Formation for lecturers and organising comittee members
     who wish a single room)

Send to: and
with the cheque of guarantee before DECEMBER 1, 1999.


From Michael Paine <>

Dear Benny

I have created a web page that is a bibliography for my Rocks from Space
series in Explorezone. See

Suggestions for additional items are welcome.

Michael Paine
The Planetary Society Australian Volunteers

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