PLEASE NOTE:
*
CCNet DIGEST, 7 April 1999
--------------------------
QUOTE OF THE DAY
Italian researchers discovered that the
scarab at the center of
King Tut's pectoral, or necklace, found
by Howard Carter in chest
n. 267, is not "greenish-yellow
chalcedony," as Carter had said,
but Libyan desert silica glass, a
natural glass that exists only
in the remote Great Sand Sea of Egypt --
the Western Desert. "Its
origin is probably celestial, caused by
the impact on the sand of
a chondritic meteorite or comet,"
says De Michele. "The glass is
scattered over a 15-mile diameter area,
but unfortunately, no
crater has been found yet."
(Discovery Online News, 4 April)
(1) MINOR PLANET (7107) PEISER
Klet Observatory <klet@klet.cz>
(2) TUTANKHAMEN'S SCARAB IDENTIFIED AS IMPACT MELT
Discovery Online News
(3) ARE THE LEONIDS METEORITES?
Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
(4) DROUGHT THEORY IS ALL WET
ACADEMIC PRESS INSIGHT, 5 April 1999
(5) FINAL MINOR PLANET WORKSHOP SCHEDULE
Richard Kowalski <bitnik@bitnik.com> wrote:
(6) IMPACT WORKSHOP, TORINO
Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
(7) EVIDENCE FOR EXTRA-SOLAR COMETS
D. de Winter et al., INSTITUTE ASTROFIS
CANARIAS
(8) INTERSTELLAR VOLATILE CONTENT OF COMETS
G.A. Blake et al., CALTECH
==================
(1) MINOR PLANET (7107) PEISER (Thank God it's not a PHA)
From Klet Observatory <klet@klet.cz>
Dear Benny Peiser,
We are glad to inform you that minor planet (7107) = 1980 PB1 has
been
named in your honor.
The citation announcing this naming appeared on Minor Planet
Circular
No. 34342 (1999 April 2) issued by the Minor Planet Center of the
IAU,
and mentioned your research interest in social anthropology as
well as
establishing and moderating of the Cambridge-Conference Network.
Name
was suggested by J. Ticha, M. Tichy and Z. Moravec, who observed
this
minor planet at the Klet Observatory at 1994 and 1996
oppositions,
prior to its numbering.
Minor planet (7107) Peiser belongs to main belt population and is
in
3.49-years elliptical orbit around the Sun. Its semimajor axis is
2.30
AU, eccentricity is 0.15 and the orbit is inclined at about 9
degrees
to the ecliptic plane. Orbital elements computed by G. V.
Williams were
published in MPC 27698. Its diameter is probably in range of 4 to
10
km.
Minor planet (7107) Peiser = 1980 PB1 was discovered on 1980
August 15
in the course of Klet photographic search programme by A. Mrkos.
It is
the 265th numbered Klet discovery.
With best regards
Jana Ticha
Milos Tichy
Zdenek Moravec
http://www.klet.cz
---------------
From MINOR PLANET CIRCULAR 34342
2 April 1999
(7107) Peiser = 1980 PB1
Discovered 1980 Aug. 15 by A. Mrkos at Klet.
Named in honor of Benny Josef Peiser (b. 1957), social
anthropologist
with particular research interest in neocatastrophism and its
implications for human, societal and cultural evolution. A senior
lecturer at John Moores University in Liverpool, he launched and
now
moderates the Cambridge-Conference Network, a scholarly network
of some
300 researchers from around the world. Name suggested by J.
Ticha, M.
Tichy and Z. Moravec, who observed this minor planet at Klet at
1994
and 1996 oppositions, prior to its numbering..
=====================
(2) TUTANKHAMEN'S SCARAB IDENTIFIED AS IMPACT MELT
Discovery Online News
http://www.discovery.com/news/archive/news990403/brief1.html?ct=370b8430
April 4, 1999
King Tut Mystery Solved
The fabulous treasure of Tutankhamen could help to shed new light
on the
ancient Egyptian civilization 77 years after the boy pharaoh's
tomb was
uncovered in the Valley of the Kings at Luxor.
Italian researchers discovered that the scarab at the center of
King
Tut's pectoral, or necklace, found by Howard Carter in chest n.
267, is
not "greenish-yellow chalcedony," as Carter had said,
but Libyan desert
silica glass, a natural glass that exists only in the remote
Great Sand
Sea of Egypt -- the Western Desert.
"This is one of Earth's most remote and inhospitable
regions," says
Giancarlo Negro, the explorer who made the discovery together
with
geologist Vincenzo De Michele.
Tut's scarab shows that some communication existed between the
Western
Desert and the Nile Valley during the pharaoh's short reign. It
is known
that between 2735 and 2195 B.C., Egyptians exploited gold and
emerald
mines in the mountains of the Eastern Desert, between the Nile
and the
Red Sea.
But nobody would have imagined that desert silica glass would lie
among
the pharaoh's gems: In order to set it at the center of the
pectoral,
the ancient Egyptians would have had to trek across 500 desert
miles,
half of them without any oasis.
The true nature of the scarab material was revealed by measuring
its
index of refraction, which was then compared with other pieces of
silica
glass. The study will be published in the May issue of the
journal
Sahara.
"Its origin is probably celestial, caused by the impact on
the sand of a
chondritic meteorite or comet," says De Michele. "The
glass is scattered
over a 15-mile diameter area, but unfortunately, no crater has
been
found yet."
James R. Underwood Jr., professor emeritus of geology at Kansas
State
University, says there might not be a crater. "It could have
been
produced by a low-altitude explosion of an asteroid or comet. The
searing heat from the explosion may have melted surficial
material that
then cooled quickly to form the glass," he explains.
The elaborate motif of the pectoral, symbolizing the voyage of
the sun
and moon through the sky, adds a new mystery -- did the ancient
Egyptians guess the celestial origins of the desert glass?
By Rossella Lorenzi
Copyright 1999, Discovery Online News
====================
(3) ARE THE LEONIDS METEORITES?
From Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
Leonids Sample Return Mission Update
Marshall Space Flight Center
http://science.nasa.gov/newhome/headlines/ast01apr99_1.htm
NASA scientists will describe initial results from a program to
catch
meteoroids in flight at the NASA/Ames Leonids Workshop April
12-15, 1999
Apr. 1, 1999: Later this month NASA scientists will present
initial
results from an innovative program to catch meteoroids in flight
through Earth's atmosphere. The paper, to be presented at the
NASA/Ames
Leonid Workshop on April 12-15, will describe tiny particles
captured
20 km above Earth's surface during last year's Leonids meteor
shower.
During the peak of the 1998 Leonids, Dr. David Noever and
colleagues
from the NASA/Marshall Space Flight Center launched a 10m weather
balloon into the stratosphere where it hovered for nearly 2 hours
above
98% of Earth's atmosphere. The payload included a digital video
camera
and an xerogel micrometeorite collector, similar in some respects
to
the cosmic dust collector on board the Stardust spacecraft now in
route
to comet Wild-2.
"The 1998 balloon flight was really intended as an
engineering test,"
says Noever. "We wanted to see if it was possible to sample
meteoroids
-- or any kind of dust -- in the stratosphere and to evaluate the
hardware in our payload before the 1999 Leonids."
As it turned out, the 1998 flight was more successful than anyone
expected. The video camera recorded a number of fireballs that
were
broadcast live on the web to nearly 100,000 people. Over
1,000,000
people saw the replay the next day.
That's not all. After the balloon payload was recovered, Noever
and his
colleagues used an Environmental Scanning Electron Microscope at
NASA's
Marshall Space Flight Center to examine the xerogel dust
collector.
They found 8 tiny craters created by impacts from particles
measuring
20 to 50 microns in diameter.
"Are they Leonid meteoroids?" asks Noever. "We
really don't know at
this point. The size of the particles is about what we would
expect for
meteoroids in the stratosphere, but they may also be
terrestrial."
The answer a least partly lies in the chemical composition of the
impactors. Particles like meteoroids that have entered the
atmosphere
at high speeds tend to be enriched in elements that are not
easily
vaporized by the extreme heat of atmospheric friction. The mass
ratios
Mg/Si, Al/Si and Fe/Si along with isotopic abundances can usually
be
used to distinguish terrestrial from extraterrestrial particles.
"The way the impactors look is important, too"
continued Noever.
"Meteroids that have been partially melted by atmospheric
friction
often have a translucent rim surrounding an unmelted, opaque
core.
Right now we're studying both the appearance of the impactors and
their
chemical makeup. Hopefully we'll have an answer soon."
Meanwhile, Noever and his colleagues plan to launch an identical
balloon this month, on April 10, to sample the dust environment
of the
stratosphere when the Earth is not passing through a major
meteoroid
debris stream like the Leonids. "During the first quarter of
every year
there's a minimum of meteor activity," explains Dr. Tony
Phillips, a
NASA astronomer. "Earth doesn't pass through any major
cometary debris
fields from about Jan 15 until late April of each year. There's
nothing
special about those months. The low meteor flux during that time
is
just a result of the random distribution of comet debris trails
in the
solar system."
The scientists working on this project hope that the balloon
flight
scheduled for April 10 will provide valuable information about
the
background environment of dust and meteoroids in the stratosphere
for
comparison with their Leonids sample. Next week Science@NASA will
provide more details about the upcoming launch and offer readers
an
opportunity to participate in this research by counting visual
meteors
on the night of the flight.
====================
(4) DROUGHT THEORY IS ALL WET
From ACADEMIC PRESS INSIGHT, 5 April 1999
http://www.academicpress.com/inscight/04051999/grapha.htm
An ancient culture was not wiped out by drought, as some scholars
have
suggested. Findings in the current Science show that the
Harrapan-Indus
civilization prospered despite dry weather for centuries on end.
The people of the Harrapan-Indus civilization, who lived in what
is now
northwestern India, flourished between 2600 and 2000 B.C. To
probe the
region's climate history, a team of geologists from Israel, the
United
States, and India used carbon-dating and chemical analysis to
examine
sediments from a now-dry lake, Lunkaransar, in the Thar Desert.
As the
level of the briny lake fell, salts and other minerals
precipitated in
distinct layers. "These lake sediments give a very
high-resolution
record of changing lake levels, which reflect changing amounts of
precipitation in the region," says Lisa Ely, a geologist at
Central
Washington University in Ellensburg.
Ely and her colleagues found that the lake has been mostly dry
for the
last 5500 years. Before then, they found, the region was wet for
15
centuries--a period that ended a millennium before the
Harrapan-Indus
peoples began to prosper.
But an arid climate by no means rules out a healthy civilization,
notes
Blair Kling, a historian at the University of Illinois,
Urbana-Champaign. Even without plentiful rain, the Harrapan-Indus
inhabitants, he says, could have depended on the Indus River for
irrigation. Kling says there is evidence that a flood may have
forced
refugees into the cities around 1600 B.C., leading to
overcrowding
that could have played a role in the civilization's downfall.
--Diana Steele
Copyright 1999, Academic Press
======================
(5) FINAL MINOR PLANET WORKSHOP SCHEDULE
From Richard Kowalski <bitnik@bitnik.com>
wrote:
The final schedule for the Minor Planet Amateur-Professional
Workshop
99 is now available at:
http://www.bitnik.com/mp/mpw99/schedule.html
Richard Kowalski
========================
(6) IMPACT WORKSHOP, TORINO
From Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
International Meeting Programs for Asteroid and Comet Threat
(IMPACT Workshop)
Date
Tuesday, 1 June 1999 - Friday, 4 June 1999
Location Torino, Italy
Contact H. Rickman or
V. Zappala
Address Oss.
Astronomico di Torino, , St. Osservatorio 220, I
10025,Torino, Italy
Phone 39 11
461 9035
FAX
39 11 461 9030
Web Site http://www.iau.org/neo.html
E-Mail zappala@to.astro.it
=====================
(7) EVIDENCE FOR EXTRA-SOLAR COMETS
D. de Winter*), C.A. Grady, M.E. vanden Ancker, M.R. Perez, C.
Eiroa:
Episodic accretion around the Herbig Ae star BF orionis -
Evidence for
the presence of extra-solar comets. ASTRONOMY AND ASTROPHYSICS,
1999,
Vol.343, No.1, pp.137-150
*) INSTITUTE ASTROFIS CANARIAS,C VIA LACTEA S-N,E-38200 LA
LAGUNA,TENERIFE,SPAIN
The results of a monitoring programme of high and intermediate
resolution spectra covering He I 5876 Angstrom, Na I D-2,D-1 and
H
alpha of the isolated Herbig Ae star BF Ori are presented. We
detect
the presence of blue and redshifted emission and absorption
components
of these lines which vary from day-today with correlated changes
suggesting a similar origin. The appearance, strength and
variations of
the redshifted Na I D absorption component on a time scale of
days show
variable accretion activity similar to that seen toward the
Herbig Ae
star UX Ori and beta Pic, suggesting evaporation of star-grazing
bodies. We estimate for one event that such a body is kilometer
sized,
evaporates at a distance of about 0.4 AU from the central star
and has
a mass comparable to comets in the solar system. A dependence was
found
of the H alpha line profile on the photometric brightness of BF
Ori
similar to that observed for UX Ori. It is evidence for
obscuration of
a dense dusty body located in the outer disk regions as no extra
absorption components from a gaseous content and no direct
influences
on the cometary activity were observed. More complex variations
of the
H alpha profile could be explained in part by absorption of
star-grazer
material, equal to the absorption at the sodium lines, and in
part by
obscuration of its Line forming region by the cometesimal. More
evidences for detections of revolving clumpy material are:
observed
changes in the velocity direction of the very strong Na I D-2,D-1
low
velocity absorption components and the observed flip over of the
relative strength of the blue and red peak of H alpha
simultaneous with
the change of blue to redshifted absorption components in both
the
Na I D-2,D-1 and He I lines. In case of orbiting bodies, the
estimated
period lies between 60 and 100 days with a distance from 0.35 to
0.57
AU, respectively. The detection of possible orbiting and
comet-like
objects in the disk of BF Ori, a 3(-1)(+2) Myr old pre-main
sequence
A5-6 IIIe star, making it a possible progenitor of the HR 4796
(protoplanetary) disk system, suggests the existence of
structures
similar to those probably present in the solar system at a time
of
formation of planetesimals. The estimated much higher than cosmic
abundances of refractory (Na) over volatile (H, He) gases for the
detected bodies supports this suggestion. Copyright 1999,
Institute for
Scientific Information Inc.
===============
(8) INTERSTELLAR VOLATILE CONTENT OF COMETS
G.A. Blake*), C. Qi, M.R. Hogerheijde, M.A. Gurwell, D.O.
Muhleman:
Sublimation from icy jets as a probe of the interstellar
volatile content of comets. NATURE, 1999, Vol.398, No.6724,
pp.213-216
*) CALTECH 150 21,DIV GEOL & PLANETARY SCI,PASADENA,CA,91125
Comets are some of the most primitive bodies left over from the
Solar
System's early history. They may preserve both interstellar
material
and material from the proto-solar nebula, and so studies of their
volatile components can provide dues about the evolution of gases
and
ices, as a collapsing molecular cloud transforms into a mature
planetary system(1,2). Previous observations of emission from
rotational transitions in molecules have averaged over large
areas of
the inner coma, and therefore include both molecules that
sublimed from
the nucleus and those that result from subsequent chemical
processes in
the coma. Here we present high-resolution observations of
emission from
the molecules HNC, DCN and HDO associated with comet Hale-Bopp.
Our
data reveal are-like structures-icy jets-offset from (but close
to) the
nucleus. The measured abundance ratios on 1-3'' scales are
substantially different from those on larger scales(3-5), and
cannot be
accounted for by models of chemical processes in the coma(2,6,7);
they
are, however, similar to the values observed in the cores of
dense
interstellar clouds and young stellar objects. We therefore
propose
that sublimation from millimetre-sized icy grains ejected from
the
nucleus provides access to relatively unaltered volatiles. The
D/H
ratios inferred from our data suggest that, by mass, Hale-Bopp
(and by
inference the outer regions of the early solar nebula) consists
of
greater than or equal to 15-40% of largely unprocessed
interstellar
material. Copyright 1999, Institute for Scientific Information
Inc.
----------------------------------------
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