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(meteorobs) Excerpts from "CCNet, 17 December 1999"




A few items of questionable relevance to our list, but making
for interesting reader for "meteorites" with broader interests.

Lew


------- Forwarded Message

From: Benny J Peiser <b.j.peiser@livjm.acdot uk>
To: cambridge-conference@livjm.acdot uk
Subject: CCNet, 17 December 1999
Date: Fri, 17 Dec 1999 13:38:58 -0500 (EST)

CCNet, 17 December 1999
-----------------------


(1) OBSERVED FIREBALL CAUSED BY RE-ENTRY OF CHINESE ROCKET
    Josep Ma. Trigo i Rodriguez <jmtrigo@ctv.es>=20

(2) SEARCH PROJECT FAILS TO DETECT FRANK'S SMALL COMETS
    Andrew Yee <ayee@nova.astro.utorontodot ca>

(3) POSSIBLE METEORITE FALL IN DUNBOGAN
    Gordon Garradd <loomberah@ozemail.com.au>=20

(4) ICE AGES, MILANKOVITCH & COSMIC DUST
    Doug Keenan <Doug.Keenan@virgindot net>=20

[...]

(6) SUNLIGHT KEEPS COSMIC DUST AT BAY
    ESA News Service, <sciweb@estec.esadot nl>

[...]

(9) METEORS & INTERPLANETARY DUST
    Robert Hawkes <rhawkes@mtadot ca>

[...]

==============================================================

(1) OBSERVED FIREBALL CAUSED BY RE-ENTRY OF CHINESE ROCKET

>From Josep Ma. Trigo i Rodriguez <jmtrigo@ctv.es>=20

Dear colleagues,
=20
We are working in the reconstruction of the definitive 27th=20
Nov. fireball trajectory. Now our data are able to resolve=20
the nature of the incident object. As you can read below we=20
confirm finally from its trajectory and velocity that the=20
fireball was'nt produced by a meteoroid but by the re-entry=20
of the chinese Shenzhou Long March rocket (catalogued as=20
#25957=3D99-61B).
=20
The fireball was really impressive and reached magnitude=20
- -10 although it was variable depending of the observational=20
distance. A lot of people saw it as a silver fireball=20
followed by a reddish wake breaking into several pieces. It=20
appeared at 21h30m U.T. approx. on Jaen (Spain), overflew=20
the Balearic Islands, Corsica and it finished near Latium=20
(region of Rome) five minutes later. The trajectory has=20
been obtained from visual observations of several=20
eyewitness in Spain, Sardinia, Corsica and Italy. The=20
lenght of this trajectory was about 1.200 Km, only possible=20
from an incident object with a little angle inclination and=20
a low geocentric velocity i.e. a re-entry event.=20
=20
The estimated velocity from our software was between 5-10=20
km/s that support the rocket hypothesis. We can hope for a=20
low orbit a velocity of  8 Km per second and about 150=20
seconds of flight. But probably they was one or two minutes=20
more due to the deceleration produced by the atmosphere.
=20
The decay time for the Shenzhou Long March rocket (#25957 =3D 99- 61 B) =

has been obtained from SatEvo analysis of the final elsets. The=20
calculation with this software send us by Manuel Montes-Palacio=20
predicts the re-entry at 20h30m UT approximately. Considering minor=20
order effects in the rocket decay in the atmosphere and the drag=20
interaction, the 27th Nov. fireball was produced undoubtedly by the=20
Shenzhou rocket.
=20
A more detailed analysis, including video images recorded 
by chance by a sailor will be send during the next month to=20
WGN, issue of the International Meteor Organization. We=20
modelize meteoroid trajectories and orbits but these=20
"artificial events" are interesting to us because they gave=20
results on luminous efficiencies for big objects and=20
important data on the aerodynamics of the object entry in=20
the atmosphere. We will include in the WGN paper detailed=20
information on the trajectory and also on meteoroid orbits=20
obtained in 1999 from the East of Spain by the Spanish=20
Photographic Meteor Network (SPMN).=20
=20
We appreciate enormously the great effort to obtain=20
additional data on the fireball to Enric Coll and Salvador=20
Sanchez (Observatori Astronomic de Mallorca), Alfonso=20
Lopez-Borgonoz (A.Adot castelldefels, Barcelona), Geoffrey=20
Cameron (Castell=F3), Roberto Gorelli (Italy), Manuel Montes=20
Palacio, Francisco Reyes and Juli Castellano-Roig (SOMYCE).=20
Finally, we are indebted to Drs. Zdenek Ceplecha, Pavel=20
Spurn=FD and Jiri Borovicka (Ondrejov Observatory, European=20
Fireball Network) to make possible with their support our=20
Spanish Fireball Network.

Josep Ma. Trigo i Rodriguez=20
SPANISH FIREBALL NETWORK (SPMN)
- -Dept. Astronomy & Astrophysics, Universitat de Valencia              =20
- -SOMYCE
E-mails: jmtrigo@ctv.es / trigo@exp.uji.es
Web page: http://www.ctv.es/USERS/jmtrigo
Phones: (+Spain Code 34)  964 -  282584  / 282968  (office)=20
(964) 395064 (part.) Fax: 964 - 285161
Postal address: c/ Manuel de Falla 26,=20
12.560 Benicassim (Castello) SPAIN

==============================================================

(2) SEARCH PROJECT FAILS TO DETECT FRANK'S SMALL COMETS

>From Andrew Yee <ayee@nova.astro.utorontodot ca>

University News Services
University of Iowa
100 Old Public Library
Iowa City IA 52242

CONTACT: GARY GALLUZZO
e-mail: gary-galluzzo@uiowadot edu
(319) 384-0009; fax (319) 384-0024

Release: Dec. 16, 1999

UI researcher fails to detect small comets

IOWA CITY, Iowa -- University of Iowa astronomy professor=20
Robert Mutel announced today that an eight-month search=20
using an Arizona-based telescope has failed to detect=20
evidence supporting a 13-year-old theory that small comets=20
composed of snow are continually bombarding the Earth.

Mutel and co-author John Fix, professor of astronomy and=20
dean of the College of Science at the University of Alabama=20
in Huntsville, presented their findings at the annual=20
meeting of the American Geophysical Union (AGU) in San=20
Francisco. In their paper, they described their examination=20
of more than 2,700 photographic images taken with the Iowa=20
Robotic Observatory (IRO), located south of Tucson, Ariz.,=20
between Sept. 24, 1998 and June 11, 1999.

"We failed to find evidence that small comets exist," Mutel=20
said. "At the same time, no such search can entirely=20
disprove their existence. But if the small comets do exist,=20
they are present in far smaller numbers than previously=20
predicted."

The small comet theory, developed by fellow UI professor=20
Louis Frank and UI research scientist John Sigwarth, holds=20
that about 20 snow comets weighing 20 to 40 tons each=20
disintegrate in the Earth's atmosphere every minute. Frank,=20
an internationally known experimental space physicist,
defended the small comet theory in a paper published in the=20
Jan. 1, 1999 issue of the AGU Journal of Geophysical=20
Research-Space Physics. The paper described how a=20
mathematical formula was used to filter out instrument=20
noise, or static, from data gathered by NASA's Polar=20
satellite. The results showed that the dark spots, or=20
atmospheric holes, photographed by cameras aboard the Polar=20
satellite vary in size and number when photographed at=20
different times and at different altitudes. However, some=20
researchers continued to believe that the dark spots=20
appearing in the images are caused by instrument noise.

Mutel and Fix said that their search using the 20-inch IRO=20
reflector telescope was designed so that expected trails=20
would be easily seen without the need for elaborate=20
statistical analysis of faint trails. Observations were=20
made each month within one week of the new moon to maximize=20
sensitivity to faint objects. The computer-controlled IRO=20
telescope was used to produce multiple shuttered images to=20
distinguish cosmic ray tracks, sensor imperfections and=20
other artifacts from potential small comet trails. The=20
telescope searched for objects moving in the same direction=20
and orbital plane as the Earth at a distance of about=20
33,000 miles from the Earth.

Out of a total of 6,148 images made, 2,718 were suitable=20
for detection of object trails with magnitude 16.5 (about=20
10,000 times fainter than the faintest stars visible with=20
the naked eye) or brighter -- easily bright enough to=20
detect the small comets. The images were recorded on CD=20
ROM, analyzed at the UI, and remain available for=20
independent analysis on the web at=20
http://denali.physics.uiowadot edu/rlm . Among several UI=20
undergraduates who assisted on the project were Christopher=20
Anson of Muscatine and William Peterson of Iowa City, both=20
seniors. Mutel and Fix said that the search, which was=20
conducted at Frank's suggestion, should have detected more=20
than 80 small comets if they are present in the predicted=20
numbers.

Frank, an experimenter, co-investigator or principal=20
investigator on some 40 spacecraft and an AGU Fellow, first=20
announced the small comet theory in 1986, after examining=20
images recorded in photographs taken by Dynamics Explorer=20
1. Frank and his colleagues had designed and built a=20
special camera to take pictures of the northern lights,=20
including the first images of the complete ring of the=20
northern lights from above the North Pole. Some of the=20
images contained unexplained dark spots, or atmospheric=20
holes. After eliminating the possibility of equipment=20
malfunction and numerous other explanations, Frank and=20
Sigwarth concluded that the atmospheric holes represented=20
clouds of water vapor being released high above Earth's=20
atmosphere by the disintegration of small comets composed=20
mostly of snow.

They calculated that more than 25,000 comets enter the=20
atmosphere each day. At that rate, the comets would have=20
added about one inch of water to the Earth's oceans every=20
20,000 years -- enough to fill the oceans over billions of=20
years. Frank said that not only their small size --=20
20-to-30-feet in diameter -- makes observation difficult,=20
but also that water striking the upper atmosphere glows=20
very faintly as compared to the bright glow of metal and=20
rock in solid meteors. The small comet theory was in the=20
news again after the 1996 launch of Polar, with its two=20
sensitive visible light cameras and one far-ultraviolet=20
light camera, offered sharper photographic images. At the=20
May 1997 AGU meeting Frank showed a series of Polar =20
satellite photographs that included a picture of a small=20
comet the size of a two-bedroom house disintegrating=20
thousands of miles above the Atlantic Ocean.

Mutel and Fix said that they were glad to be able to=20
contribute data to the discussion and added that the debate=20
over the small comet theory will likely continue for many=20
years to come.


==============================================================

(3) POSSIBLE METEORITE FALL IN DUNBOGAN

>From Gordon Garradd <loomberah@ozemail.com.au>=20

Dear Benny,=20

I have spoken by phone with Mr Paul Hancock, whose house=20
has the hole in the roof, he is becoming rather tired of=20
phone calls after being contacted by 17 media=20
organisations! He told me the sound was only heard by his=20
family inside the house, at 10:05 pm ( 11:05UT), and the=20
next door neighbour heard no sound at all. Mr Hancock heard=20
no other sounds and was unaware of any other reports of=20
sounds in the region, nor reports of fireballs. I put my=20
all-sky camera out at 10:20 UT, so may have recorded any=20
potential fireball, although my eastern view is obstructed=20
by trees in the direction of Dunbogan.

Mr Hancock described the dozen or so fragments he still has=20
as having a total volume of about half a golf ball. He gave=20
some of the material to the police for analysis, I=20
suggested he send some to the Australian Museum for a=20
proper analysis. He said the material seemed to have a=20
charcoal coloured lustrous surface "less than one sixteenth=20
of an inch thick" and inside a very even non -crystalline=20
"ghost grey" colour with no apparent variations.=20

The object smashed through glazed concrete tiles and the=20
ceiling and landed on the floor, where he found many pieces=20
of it mixed in with pieces of the tiles, he said he could=20
find no burn marks.
=20
Regards, Gordon

==============================================================

(4) ICE AGES, MILANKOVITCH & COSMIC DUST

>From Doug Keenan <Doug.Keenan@virgindot net>=20

Benny,
=20
The research described in the following suggests that ice=20
ages are caused, in part, by variations in Earth's orbit=20
that result in changes in the flow of cosmic dust into the=20
atmosphere. The variations are influenced by the=20
gravitation of other planets.

http://news.excite.com/news/uw/991208/tech-247

Cheers,
Doug Keenan

==============================================================

(6) SUNLIGHT KEEPS COSMIC DUST AT BAY

>From ESA News Service, <sciweb@estec.esadot nl>

The force of sunlight is keeping part of our solar system dust free -=20
at least free from a particular type of dust.  Markus Landgraf, now=20
working at ESA's operations centre ESOC in Germany and his=20
international team of colleagues, made this discovery after poring over =

data collected by the dust detector on board the Ulysses spacecraft.

More at:
http://sci.esa.int/newsitem.cfm?TypeID=3D1&ContentID=3D8571&Storytype=3D=
13

==============================================================

(9) METEORS & INTERPLANETARY DUST

>From Robert Hawkes <rhawkes@mtadot ca>
=20
IAU Comm. 22 (Meteors and Interplanetary Dust) Electronic Notice

There are a limited number of extra copies of the=20
Proceedings of the Meteoroids 1998 International Conference=20
(held Aug 17-21 1998 in Tatranska Lomnica, Slovakia)=20
available for sale to libraries and those individuals who=20
wish to purchase a copy.  The volume contains  80 papers=20
(invited reviews and contributed research papers), and is=20
405 pages in length. The main divisions of the volume are=20
Atmospheric Interaction, Meteor Observations, Meteor=20
Showers and Meteoroid Streams, Dynamics in Space, and=20
Physical Studies and Meteorites.. The volume is edited by=20
W.J. Baggaley and V. Porubcan, and is published by the=20
Astronomical Institute of the Slovak Academy of Sciences.=20
The program for the conference (which lists paper titles)=20
is still available on the www at:
http://www.ta3.sk/~ne/Meteoroids98/ann3.html

Copies of the Meteoroids 1998 Proceedings are available for 40 US$.

For further information and to place orders please contact:

Dr. Vladimir Porubcan
Astronomical Institute, SAV
Dubravska 9
842 28 Bratislava
Slovak Republic

astropor@savba.savba.sk

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THE CAMBRIDGE-CONFERENCE NETWORK (CCNet)
----------------------------------------
The CCNet is a scholarly electronic network. To subscribe/unsubscribe,=20
please contact the moderator Benny J Peiser <b.j.peiser@livjm.acdot uk>.=20
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copyright holders. The fully indexed archive of the CCNet, from=20
February 1997 on, can be found at =
http://abob.libs.ugadot edu/bobk/cccmenu.html

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