Date sent: Mon, 21 Apr 1997 12:17:59 -0400 (EDT)
Subject: Re: rules & regulations
Priority: NORMAL


Due to some recent messages by non-members on this
list and legitimate complaints about their tone and
relevance, I would like to emphasize that the
cambridge-conference network is NOT (and was not set
up as) a regular e-mail "discussion group." Instead it
is intended as a scholarly network for the
dissemination of scientific research findings,
newsworthy information, announcements and reviews of
new publications, conferences, meetings, etc. related
to the multidisciplinary topics of the 2nd SIS
Cambridge Conference. Since we all are exposed to an
ever increasing flow of electronic information,
messages on this list should be kept to a minimum of
relevant issues of general interest.

Can I kindly ask members to comply with this format.

Benny J Peiser


Date sent: Mon, 21 Apr 1997 11:51:02 -0400 (EDT)
Subject: NEO News (4/19/97)
Priority: NORMAL

NEO News (4/19/97)

Dear Friends and Students of NEOs:

Following are several news items dealing with recent
NEO activities in the US Congress, NASA and the USAF.

David Morrison


1. The Science Committee of the US House of
Representatives has just (April 14) authorized NASA to
spend an additional $2 million in Fiscal Year 1998 on
NEO searches and related research. Note that this is
not an appropriation of funds. If this money were
appropriated (in a separate bill) and NASA chose to
spend the funds as directed, NASA support for NEO
work would go from $1 million per year to $3 million
per year.

2. Gene Shoemaker offers testimony on NEOs to the
House Science Committee:


Statement by Eugene M. Shoemaker, Lowell Observatory
and Scientist Emeritus, U.S. Geological Survey

An estimated 1500 asteroids larger than one
kilometer in diameter revolve about the sun on
short-period Earth-crossing orbits. On average, about
one such object strikes the Earth per 150,000 years.
Collision of a one-kilometer diameter asteroid on the
land is expected to produce a crater about 15
kilometers in diameter and to eject an enormous amount
of dust, much of which would be spread over the
entire Earth in less than an hour. The amount of dust
produced will depend partly on the characteristics of
the target rocks, but it is thought that the amount
may be great enough to cause a major drop in global
temperatures for a period of months. The largest
effect on humanity probably would arise from loss of
crop production if a major impact occurred on land
during the growing season of the northern hemisphere.
Impact in the ocean probably would cause a less severe
global perturbation of the atmosphere but could cause
devastating tsunamis along coasts.

At the present time, about 100 Earth-crossing
asteroids larger than one kilometer in diameter, about
seven percent of the estimated population, have been
discovered. None of the discovered asteroids with
well determined orbits will strike the Earth in the
near future. There is about one chance in a thousand
that one of the undiscovered asteroids larger than a
kilometer revolves on an orbit leading to collision
with the Earth in the next 150 years. If all the
potentially threatening asteroids were discovered,
however, the risk to Earth would no longer be a matter
of chance. We would know whether a collision is
imminent. The time of impact could be predicted
centuries in advance, and the place of impact could be
predicted fairly accurately decades in advance.

Currently NASA is supporting work at three
institutions to carry out a survey for Earth-crossing
asteroids. Two survey projects are on line, the
Spacewatch project at the University of Arizona and
the NEAT project at the Jet Propulsion Laboratory; a
third, the LONEOS project at Lowell Observatory, will
begin observations this year. The NEAT project is a
joint effort between the Jet Propulsion Laboratory and
the U.S. Air Force. A CCD camera built by the Jet
Propulsion Laboratory is mounted on a 1-meter
telescope that is part of the GEODSS satellite-
tracking network of the Air Force at a site on Maui,
Hawaii. Earth-crossing asteroids larger than
one-kilometer diameter are now being discovered at a
rate of about 20 per year. When all three projects
become fully operational, it is expected that 90
percent of Earth crossers larger than one kilometer
could be discovered and catalogued in about 20 to 30
years with the current level of support of about $1.2
million per year. The current support includes funds
for orbit determination and cataloging of the
discovered asteroids and for radar observations of
selected asteroids.

The rate of discovery can be increased with improved
instrumentation and by instrumenting additional
telescopes. If an agreement is entered into by NASA
and the Air Force, two more telescopes in the Air
Force GEODSS network could be instrumented with large
format CCD cameras. A similar large format CCD camera
is needed for a new 1.8-meter telescope nearing
completion for the University of Arizona's Spacewatch
project. The efficiency of surveying the sky can be
further enhanced by transferring part of the
observational task of orbit determination for
newly discovered asteroids to small telescopes.
Capital costs for the CCD cameras needed are about $1
million. With the suggested additional
participation by the Air Force, the time required for
discovery of 90 percent of the Earth-crossing
asteroids larger than one kilometer diameter could be
reduced to about 10 years with an annual level of
support by NASA of $1.7 million per year (about 40
percent higher than the current level).

Two NASA spacecraft will conduct close-range
observations of near-Earth asteroids. The NEAR
spacecraft, which was launched in February, 1996, will
rendezvous with (433) Eros in February, 1999. Data to
be obtained include the size, shape, and spin state of
the asteroid, the topography, surface composition, and
geology, and information on the interior of the body
from its gravity and magnetic fields. The New
Millenium Deep Space 1 spacecraft, to be launched in
July, 1998, is scheduled to fly by asteroid (3352)
McAuliffe in January, 1999. High resolution
observations of the asteroid will be made during the
flyby but will be less complete than those expected
for Eros. Although both Eros and McAuliffe can make
moderately close approaches to Earth, neither is

A mission to two or more Earth-crossing asteroids
could be accomplished with the Clementine II
spacecraft of the Air Force. Currently $45 million
dollars have been appropriated for Clementine II,
which is insufficient for an asteroid mission. An
additional $75 million and participation by NASA would
be needed to carry out an asteroid mission. A probe
is being designed that could be released to impact an
asteroid during flyby. Observations of the impact
could provide information on the density and strength
of materials on the asteroid.


NASA and the Air Force Space Command have agreed
to work together in several areas of mutual interest
in the hopes of saving both organizations costs and
sharing in new technologies to benefit future
spaceflight and spacecraft.

"This agreement exemplifies NASA's commitment to
finding ways to reduce cost and, where appropriate,
share our assets with the Air Force for greater
efficiencies in our respective missions," said NASA
Administrator Daniel S. Goldin.

Under the terms of the agreement signed by Goldin
and Air Force Space Commander General Howell M. Estes,
III, NASA and the Air Force will form partnership
teams to study seven areas of potential cooperation.
These areas include studying the cost feasibility of
launching Defense Support Program satellites from the
Space Shuttle in 1999; possible expanded use of the
Shuttle for Air Force technology payloads; and
consolidating plans that outline space transportation
needs of NASA and the Air Force.

NASA and the Air Force also will examine their
respective infrastructures and common-use facilities;
develop and coordinate an implementation plan to
address orbiting space debris; and possible
collaboration on the Clementine II project; and expand
cooperation in space weather environment research and
data sharing.

The partnership teams are scheduled to provide an
interim report on their findings to senior management
of both organizations in mid-July of this year.


NASA reports the selection of 2 target asteroids for
the nominal Clementine 2 mission: 1986JK (intercept on
6/5/2000) and 4179 Toutatis (intercept on 10/10/2000).
Both asteroids will be impacted by hypervelocity
Microsats, and NASA may be involved in the analysis of
scientific (as opposed to military) data from these
hypervelocity impacts. The first Clementine 2
NASA Science Definition Team meeting, chaired by Gene
Shoemaker, was held in Flagstaff on April 17.

David Morrison

CCCMENU CCC for 1997