PLEASE NOTE:
*
Date sent: Fri, 20 Jun 1997 16:15:41 -0400 (EDT)
From: Benny J Peiser <B.J.PEISER@livjm.ac.uk>
Subject: NEAR Fast Approaching Asteroid 253 Mathilde
To: cambridge-conference@livjm.ac.uk
Priority: NORMAL
from: Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
Applied Physics Laboratory
Johns Hopkins University
Laurel, Maryland
FOR IMMEDIATE RELEASE: 18 June 1997
NEAR FAST APPROACHING ASTEROID 253 MATHILDE
The Near Earth Asteroid Rendezvous (NEAR) spacecraft is closing
in
fast on the main-belt asteroid 253 Mathilde, as scientists
prepare
for the closest-ever study of an asteroid. On June 27, starting
at
about 8:50 a.m. EDT, NEAR will be streaking past Mathilde at
22,000
miles per hour (10 kilometers per second), just 750 miles (1,200
kilometers) from the asteroid.
For 25 minutes NEAR will take a series of 534 images using a
multispectral imager. "The flyby is an important opportunity
to learn
more about asteroids in general and C-type [carbon-rich]
asteroids in
particular," says Dr. Scott L. Murchie, Instrument Scientist
from The
Johns Hopkins University Applied Physics Laboratory (APL),
Laurel,
Md. "With the data we get we will be able to determine
Mathilde's
size, shape, landforms, brightness, and color properties."
Using a combination of spacecraft radio tracking and imaging data
as
well as Earth-based radar imaging techniques, researchers will be
able to determine, for the first time, accurate bulk density for
an
asteroid. "The bulk density will provide clues as to how the
asteroid
formed and whether it is a monolithic structure or a collection
of
smaller fragments," says Dr. Donald K. Yeomans of NASA's Jet
Propulsion Laboratory, who heads up the radio science experiment.
As NEAR reaches its closest proximity to Mathilde a planned loss
of
signal will keep researchers in suspense until the captured data
begins to flow into APL's Mission Operations and Science Data
centers
at about 9:40 a.m. The first complete image is expected to be
available later that afternoon.
"This is the first science data return of NASA's Discovery
Program,"
says Dr. Robert W. Farquhar, NEAR Mission Director at the APL,
where
the spacecraft was designed and built. "What makes it even
more
special is that it is 'bonus science' because it is an add-on to
NEAR's primary mission to study asteroid 433 Eros, at virtually
no
additional cost."
Because the Mathilde flyby was conceived after spacecraft
integration
had begun, the multispectral imager was not designed for a fast
flyby. Still, researchers expect to get images and take
measurements
that will provide significant new information about Mathilde,
which
they can compare with data the Galileo spacecraft obtained during
its
flybys of Gaspra (1991) and Ida (1993) for a better understanding
of
asteroids.
"Mathilde is a black asteroid made of carbon-rich rock,
believed by
many to be the most primitive -- least changed in the last 4.5
billion years -- material left in the asteroid belt," says
Dr. Joseph
Veverka of Cornell University, who leads the mission's Science
Team.
"Such material has never been studied up close by a
spacecraft."
Located in the outer part of the asteroid belt, Mathilde will
also be
the largest asteroid ever visited by a spacecraft. It was
discovered
in 1885 and is believed to be named to honor the wife of
astronomer
Moritz Loewy, then-Vice Director of the Paris Observatory.
Interest in Mathilde was minimal until the NEAR flyby was
announced
in 1995. Since then ground-based telescopes have been used to
determine, among other things, that Mathilde is a C-type asteroid
and
is one of the darkest objects in the solar system since it
reflects
only 4 percent of the light falling on it. It has been determined
that Mathilde is approximately 38 miles (61 kilometers) across
and
has an amazingly slow rotation rate (17.4 days), which intrigues
scientists since only two asteroids, 288 Glauke and 1220 Clocus,
have
longer rotation periods.
When NEAR encounters Mathilde it will be roughly 2.0 astronomical
units from the sun and 2.2 AU from the Earth (AU=the mean
distance
between the Earth and sun). The spacecraft's great distance from
the
sun has resulted in the decision to use the limited power
supplied by
the solar cells frugally by activating only one of NEAR's six
instruments, the multispectral imager.
The NEAR spacecraft, launched Feb. 17, 1996, from Cape Canaveral
Air
Station in Florida, is the first spacecraft powered by solar
cells to
operate beyond the orbit of Mars. Its encounter with Mathilde
occurs
as the spacecraft heads back toward Earth after a wide swing
around
the sun for a "slingshot" gravity assist in January
1998. The
maneuver bends the NEAR trajectory nearly 11 degrees out of the
ecliptic to put it in an orbit that will match Eros' orbital
plane.
The spacecraft will reach Eros Jan. 10, 1999, orbit the asteroid
for
a year, and end its mission Feb. 6, 2000, with a controlled
landing
onto its surface.
NEAR Science Team Group Leaders are: Joseph Veverka, Cornell
University; Jacob I. Trombka, NASA/Goddard Space Flight Center;
Mario
H. Acuna, NASA/GSFC; Maria T. Zuber, MIT and NASA/GSFC; and
Donald K.
Yeomans, NASA/Jet Propulsion Laboratory. Andrew Cheng, JHU/APL,
is
the Project Scientist. Mission Operations have been the
responsibility of The Johns Hopkins University Applied Physics
Laboratory.
---------------------------------------------------------
For more information contact Helen Worth, JHU/APL Office of
Public
Affairs. Phone: (301) 953-5113; e-mail: Helen.Worth@jhuapl.edu;
or
fax: (301) 953-6123 or Donald Savage, NASA Headquarters Office of
Space Science. Phone (202) 358-1547; e-mail: dsavage@hq.nasa.gov;
or
fax: (202) 358-3093.
Mathilde flyby updates can be obtained on the Mathilde homepage
at:
http://sd-www.jhuapl.edu/NEAR/Mathilde.
Photographs of the first
Mathilde images will be available sometime during the afternoon
of
June 27. Also available are photographs of the NEAR spacecraft,
launch, and artists' concepts of the rendezvous at Eros, and a
video
of Mathilde flyby animation with B-roll footage of spacecraft
development and testing.
*
Date sent: Fri, 20 Jun 1997 16:11:44 -0400 (EDT)
From: Benny J Peiser <B.J.PEISER@livjm.ac.uk>
Subject: SODOM & GOMORRAH
To: cambridge-conference@livjm.ac.uk
Priority: NORMAL
SODOM, GOMORRAH AND THE OTHER LOST CITIES OF THE PLAIN
Members of this network will be aware by now that the Cambridge
meeting in July will also focus on the sudden demise of the first
urban civilisations of mankind at around 2300 BC. One of the most
famous biblical stories which is often related to these dramatic
events is the account of how Sodom and Gomorrah were destroyed by
heavenly terror raining from the sky. Genesis 19:23 states that
"the
Lord rained upon Sodom and Gomorrah sulforous fire .... out of
the
heaven" - "a fair description of a meteorite
shower", as Geoffrey
Lean commented in the INDEPENDENT ON SUNDAY (30 March 1997). In
recent weeks, science journalists in Britain and Israel have
mentioned this story in their reports about the Cambridge
meeting.
Whilst most scholars believe in a seismic explanation of this
event, others blaim abrupt climate changes for these
destructions.
Members who are interested in archaeological and climatological
research on Early Bronze Age civilisation collapse will therefore
find the following paper by Professor Nissenbaum of Israel's
prestigious Weizmann Institute of Science of great interest,
especially since he attempts to reconcile the archaeological
evidence
for widespread seismic activity with the climatiological record.
Yet
the question as to why an abrupt climate change appears to have
coincided with widespread earthquake activities in the Southern
Levant at the end of the EBII periode, remains open.
Benny J. Peiser
-----------------------------------------------------------------
A Nissenbaum: "SODOM, GOMORRAH AND THE OTHER LOST CITIES OF
THE
PLAIN: A CLIMATIC PERSPECTIVE." In: CLIMATIC CHANGE, 1994,
Vol.26,
No.4, pp.435-446
Certain aspects of the biblical story of the Cities of the Plain
have
in recent years become widely accepted. Among them is the placing
of
those cities in the southern basin of the Dead Sea, the
assumption
that those cities are now covered by Dead Sea water and, in
particular, the belief that their destruction was due to
catastrophic
geological causes, such as an earthquake. The Bible emphasizes
the
agricultural richness of the Jordan plain prior to the upheaval
of
Sodom and Gomorrah and its catastrophic transformation into a
wasteland. Thus, stripped of ethical and religious overtones, the
scenario is that of a rapid climatic change that converted a
densely
inhabited and richly watered area into an infertile salt playa.
The region northeast and southeast of Jericho, which today is
quite
barren as a result of the upward movement of salty ground water
but
which contains some of the World's earliest known agricultural
settlements, fits such a picture. Dating the Sodom event to
approximately the 23rd-21st centuries B.C. supports the idea that
a
major climatic change that occurred between the Early and Middle
Bronze Ages and which resulted in profound transformations in the
Middle East such as the collapse of the Ancient Kingdom of Egypt,
the
invasion of the Fertile Crescent by the Semitic desert nomads,
and
the collapse of Early Bronze Age civilization in Palestine - is
also
responsible for the Sodom story. Although the data are far from
complete, desiccation during this period is indicated by
palynological evidence pointing to the decimation of forests in
Northern Israel, paleobotanical evidence from Southern Israel,
the
deposition of salt layers in the Dead Sea, the abandonment of
almost all settlements in the Negev Desert of Southern Israel,
the Jordan valley and Southern Jordan, except those which were
associated with perennial springs, and further afield the drastic
lowering of the level of Lake Moeris in Lower Egypt. This
scenario
does not exclude the possibility that a major earthquake - which
may
have occurred during this period - was considered to be the cause
of
the final physical destruction of the Cities of the Plain,
delivering
a coup de grace to a collapsing society, and which became through
the
mists of time and legend, the only agent of destruction.
*
Date sent: Fri, 20 Jun 1997 08:59:10 -0400 (EDT)
From: Benny J Peiser <B.J.PEISER@livjm.ac.uk>
Subject: Briefing Set For NEAR Spacecraft Flyby of Asteroid
Mathilde
To: cambridge-conference@livjm.ac.uk
Priority: NORMAL
from: Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
Don Savage
Headquarters, Washington, DC June 18, 1997
(Phone: 202/358-1547)
Helen Worth
The Johns Hopkins University Applied Physics Laboratory, Laurel,
MD
(Phone: 301/953-5113)
NOTE TO EDITORS: N97-42
BRIEFING SET FOR NEAR SPACECRAFT FLYBY OF ASTEROID MATHILDE
The Near Earth Asteroid Rendezvous (NEAR) spacecraft's
planned flyby of the asteroid 253 Mathilde on June 27 is the
topic
of a media briefing scheduled for Monday, June 23, at 1 p.m. EDT.
The briefing will preview planned mission activities and science
objectives for the first flyby of this type of dark and primitive
main-belt asteroid.
The briefing will originate from NASA Headquarters
Auditorium, 300 E St., S.W., Washington, DC, and will be carried
live on NASA TV with two-way question-and-answer capability for
reporters covering the event from participating NASA centers.
Panelists will be:
-- Dr. Wesley T. Huntress, Jr, Associate Administrator,
Office of Space Science, NASA Headquarters, Washington, DC
-- Robert W. Farquhar, NEAR Mission Director, The Johns Hopkins
University Applied Physics Laboratory (JHUAPL), Laurel, MD
-- Dr. Donald K. Yeomans, NEAR Science Team, Jet Propulsion
Laboratory, Pasadena, CA
-- Dr. Peter C. Thomas, NEAR Imaging Team, Cornell University,
Ithaca, NY
-- Dr. Andrew F. Cheng, NEAR Project Scientist, JHUAPL
NASA Television is broadcast on Spacenet 2, transponder 5,
channel 9, C-Band, located at 69 degrees West longitude, with
horizontal polarization. Frequency will be on 3880.0 megahertz,
with audio on 6.8 megahertz. Audio of the broadcast will be
available on voice circuit via the Kennedy Space Center, FL, on
407/867-1220.
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