PLEASE NOTE:
*
Date sent: Thu, 22 May 1997 09:24:50 -0400 (EDT)
From: Benny J Peiser <B.J.PEISER@livjm.ac.uk>
Subject: SPACEGUARD FOUNDATION-INFO 1997/01
To: cambridge-conference@livjm.ac.uk
Priority: NORMAL
MESSAGE FROM THE SPACEGUARD FOUNDATION
This message comes from The Spaceguard Foundation. It is one in
an
occasional series of messages concerned with Near-Earth
Objects (NEOs); these may be concerned with recent discoveries,
implications, news stories from the mass media, political action,
or related matters.
Further information about The Spaceguard Foundation, and how to
contact its members, is available from the WWW home page:
http://www.brera.mi.astro.it/SGF
The Board of Directors of The Spaceguard Foundation.
Andrea Carusi
Mario Carpino (Secretary)
Syuzo Isobe
Brian Marsden
Karri Muinonen
Gene Shoemaker
Duncan Steel
========================================================================
ITEM 1: RECENT ACTIVITIES IN THE SEARCH AND TRACKING ARENA
The cessation at the end of 1994 of the photographic NEO
programs conducted by Eleanor Helin and by Gene Shoemaker with
the
0.46-m Schmidt telescope at Palomar Observatory in California
produced a noticeable perturbation in the rate of discoveries of
comets and near-earth asteroids. This effect was particularly
evident during 1995, before Helin's NEAT ("Near-Earth
Asteroid
Tracking") program using a JPL CCD camera on a GEODSS
telescope
operated by U.S. Air Force personnel in Hawaii, as well as other
more recent CCD surveys, got underway. Only the University of
Arizona's scanning-CCD Spacewatch search and the Australian
program
involving the examination of U.K. Schmidt plates and CCD
follow-up
were active during 1995, and the latter was operating at a rather
low level prior to its final surge before the program was
terminated in late 1996. The fact that one of the intrinsically
brightest comets in history could be discovered visually by
amateur
astronomers when it was only 22 degrees from opposition is
testament to the rather sorry state of NEO activities in 1995.
NEAT and the Australian program, as well as the high-latitude
photographic program carried out by T. B. Spahr and C. W.
Hergenrother with a 0.4-m Schmidt in Arizona and two photographic
programs for more general studies of asteroids with the 1-m
Schmidt
at the European Southern Observatory, nicely supplemented
Spacewatch in 1996 and brought the number of discoveries back to
the 1994 level.
1997 dawned with Spacewatch still dominating the field with
its discovery of four of the seven comets, six of the 12 Apollos
and Atens (i.e., asteroidal objects with their perihelia inside
the
orbit of the earth), and all but one of the five Amors (further
asteroidal objects out to a perihelion distance of 1.3 AU)
reported
before the end of April. The NEAT program suffered from unusually
poor weather and from a cutback in operation that allows it a
maximum of only six observing nights each month, in contrast to
Spacewatch's 18. Nevertheless, NEAT discovered one comet, one
Aten
and the remaining Amor during the four-month interval. The sixth
of
the comet discoveries was by a Japanese amateur using a CCD, and
the seventh was a "traditional" photographic discovery
during the
second Palomar Sky Survey. Of the remaining Apollo discoveries,
one was found in the course of a CCD observation with the 1.0-m
Schmidt telescope at the Kiso Station of the National
Astronomical
Observatory of Japan, one in the course of an asteroid survey
operated by students with the Beijing Observatory's 0.6-m Schmidt
at Xinglong, one was found by an Italian amateur astronomer,
and two were found in the course of LINEAR, the Lincoln
Laboratory's Near-Earth Asteroid Research survey, which operates
on
a GEODSS telescope in New Mexico.
LINEAR is an important new search program that promises to be
a very significant contributor to the NEO cause. While its
faintest detections of main-belt asteroids, at around V = 20.5
comparable to that in the NEAT program, are more than one
magnitude
brighter than the faintest detections by Spacewatch, LINEAR's
strength comes from its fast-readout CCD, which typically allows
the saturation of several search areas extending for 8 degrees
along the ecliptic and perhaps 9 degrees in latitude., spread
over
an average of six or seven clear nights each month. In contrast,
the Spacewatch latitude range is typically only 2 degrees, while
NEAT coverage falls in between but with less continuity than in
the
other two programs.
Of course, there is no value to making a discovery that is
not followed up with further observations. Initial information
about many of the objects discussed above, as well as other
candidate NEOs that could not be confirmed, is routinely placed
in
The NEO Confirmation Page maintained on the World Wide Web by the
Minor Planet Center, even on the basis of single-night
detections.
Key confirmation and other early follow-up observations have been
obtained, most notably by Dave Balam and Chris Aikman with the
1.8-m reflector at the Dominion Astrophysical Observatory in
British Columbia and by Jana Ticha and her associates with the
0.6-m reflector at the Klet Observatory in the Czech Republic.
A handful of amateur astronomers in the U.S. and Italy are also
involved in this work, as are several Japanese amateurs,
particularly when the follow-up is of a comet. Initial
information
about comets has been published on the IAU Circulars. As soon as
the orbit of an Aten, Apollo or Amor is tolerably determined,
this
information has been routinely supplied in the Minor Planet
Electronic Circulars, with subsequent updates appearing in some
cases as the orbital solutions are improved.
Although observations may sometimes be obtained over a span
of several months at the discovery opposition, it is--at least,
in
the absence of radar data or a chance identification of
observations from earlier years--essential to recover an object
at
the next suitable opposition (or reasonable elongation from the
sun) before one can really say that an orbit is
"established", in
the sense that reliable predictions for the object in the future
are guaranteed. In addition to new discoveries, the Minor Planet
Electronic Circulars carry information about NEOs (or the IAU
Circulars in the case of comets) at their crucial second
apparitions. During the first four months of 1997 there were four
Apollos and five Amors in this category. Six of these nine
recoveries were made by Hergenrother, generally with the 1.2-m
reflector at the Smithsonian Astrophysical Observatory's Whipple
Observatory in Arizona. This is another new observing program
that
has been initiated only during the past year, and it replaces the
follow-up program conducted with the 1.5-m reflector at the Oak
Ridge Observatory in Massachusetts--a program that was carried
out
by Richard McCrosky for very nearly a quarter of a century and
one
of the earliest successes of which was the 1973 recovery of
(1862)
Apollo itself after it had been lost since its discovery
opposition
41 years earlier.
While there is value to well-conducted observational programs
involving comets and asteroids generally, few of the objects
discovered are even remotely likely to be an actual threat to the
earth during the foreseeable future. All of the comets of 1997
have
perihelion distances well in excess of 2 AU. It is useful to
define
a category of PHAs ("potentially hazardous asteroids")
that
currently have the possibility of passing within 0.05 AU and have
an absolute visual magnitude brighter than 22 (so as to include
all
objects likely to be 200 meters across). There are currently 98
objects in this category, of which 13 were discovered in 1994,
three in 1995, 11 in 1996 and five during the first third of
1997.
One of the points about the Spacewatch discoveries is that many
of
them are intrinsically very faint objects close to the earth but
too small to survive passage through the atmosphere--or at least
do
more than very local damage. Even so, Spacewatch has consistently
been the most important contributor to PHA discoveries in recent
years, with six in 1994, all three in 1995, four in 1996 (with
three each by NEAT and the Australian program) and two so far in
1997.
==========================================================================
ITEM 2: NEW ITALIAN NEO SEARCH AND TRACKING PROGRAM
A new search and tracking program has been initiated in Italy.
The
program (CINEOS: Campo Imperatore NEO Survey) is a component of
the
national ITANET project, aimed at building and testing a
small-scale network for NEO observations. The program, in which
seven Italian institutions participate, uses at the moment the
Schmidt telescope of the Campo Imperatore station (Observatory of
Rome), on the Gran Sasso massif at an altitude of 2180 meters.
This
is a 90/60 cm f/3 instrument with a 2k x 2k CCD in the focal
plane.
Its FOV is of about one square degree. With optimal conditions
the
instrument is able to reach mag 21. The primary objective of the
program, mainly thanks to the very good observing conditions at
the
site, is to systematically search for objects at low solar
elongations (50-120 deg), especially Atens. The program is also
aimed at providing good astrometric follow-up of discovered
objects. At this moment the program may count on two weeks
of observation each month, bracketing the full moon. The
principal
observers are: Andrea Boattini (IAS-Rome) and Andrea Di Paola and
Fernando Pedichini (Obs. of Rome), but several other Italian
astronomers are participating in the program. The ITANET project
is now providing upgrading of two other Schmidt instruments at
Asiago (Padua) and Serra la Nave (Catania) observatories. The
three
instruments will be fully operational by mid-1998. Coordination
of
observations and archiving of images will be performed at the
IAS-Reparto Planetologia in Rome. It is anticipated that, after
the
necessary initial tests, the ITANET network will become a
component
of the Spaceguard System.
==========================================================================
ITEM 3: NEW SPACEWATCH TELESCOPE TO BE INAUGURATED
Since it began operations for NEO searching in 1989, the 0.9
meter
Spacewatch Telescope operated by Tom Gehrels (University of
Arizona) and his team at Kitt Peak has been the leading
instrument
for discoveries of near-Earth asteroids, delivering a large
fraction of the NEAs found in the kilometer size range as well as
identifying objects of unprecedented small size (ten meters and
even lower). For the past several years the Spacewatch team has
been developing a new alt-az folded prime focus telescope with an
aperture of 1.8 meters, F/2.7, which was also installed on Kitt
Peak. The 1.8-m Spacewatch Telescope and building will be
inaugurated on June 7th.
==========================================================================
ITEM 4: THE CLEMENTINE II PROJECT
A project currently being planned within the US is a spacecraft
named Clementine II. Clementine I operated three years ago,
completing a very successful mission to the Moon, multispectral
scans of much of the lunar surface being obtained along with the
tentative identification of polar crater ice from radio data.
Clementine I was then scheduled to be sent on to the NEA (1620)
Geographos, but an attitude control jet malfunction led to
mission abort.
Clementine II is now under study by the US Department of Defense,
with the likelihood of NASA involvement. As for the first
mission,
Gene Shoemaker is chairing the science team. Whilst the precise
mission has yet to be finalized, it seems likely that after
launch
in late 1999 and a phase in terrestrial orbit, and possibly lunar
orbit, Clementine II will be sent on to fly-by two NEAs [(4179)
Toutatis and 1986 JK] in the year 2000. A desired feature of the
mission would be sending two small probes to impact these
asteroids
to aid in investigations of their physical nature.
==========================================================================
ITEM 5: THE SPACEGUARD CENTRAL NODE
The Spaceguard Foundation is about to sign a contract with ESA
for
the establishment of a "Spaceguard Central Node" (SCN)
using ESA
funds. This is a pilot project, of 10 months duration, to be
started at the end of May 1997. The goal is to build, both from
hardware and software viewpoints, a facility able to connect and
coordinate all observatories involved in NEO research. The
provisional structure of the SCN, which will be located at the
SGF
Headquarters in Rome, is as follows:
1) The current WWW page of The Spaceguard Foundation will be
upgraded and will contain all information needed by SGF members
and
non-members concerning SGF activity.
2) A tutorial section will address all the scientific issues
related to NEOs, from origin and dynamics, to physics and
mineralogy, to impact processes. This section is meant to provide
background information to newcomers and a forum for discussion on
the social and political aspects of the NEO researches. The
section
will also provide a connection to the NEO Journal, a new
scientific
(electronic) journal the establishment of which is under
discussion
with the Kluwer publishing house; this journal would be
completely
devoted to NEO research.
3) Another section will eventually become the backbone of the
Spaceguard System. This section will contain access to the Minor
Planet Center facilities, a "software tools"
collection, an
exhaustive archive of CCD frames (and the software needed to
manage
it), and a bibliographic section. The most important feature of
this section, however, will be the "situation room",
where
information will be inserted about participating observatories,
their observing schedules, opportunities and suggestions. A
continuously updated chart of "who is observing what"
will also be
provided.
4) A last section will contain links to all centers, institutions
and people who are in any way connected to NEOs, in whatever
scientific and non-scientific discipline.
==========================================================================
ITEM 6: THE SPACEGUARD SOUTHERN TELESCOPES
The cessation of all NEO astrometric tracking in the southern
hemisphere (see items 10, 11 and 12 below) has meant that there
is
a special need for the development of a southern hemisphere NEO
observation site. Because of this The Spaceguard Foundation has
made one if its highest priorities the establishment of a new
southern hemisphere NEO observatory.
The proposed Spaceguard Southern Telescopes would consist of two
large instruments dedicated to NEO discovery, follow-up, and
physical studies. The smaller 4-meter telescope would be
dedicated
to the actual discovery of NEOs, whereas the time on the larger
8-meter telescope would be concentrated on follow-up astrometry,
photometry, polarimetry, and specroscopy. The Spaceguard Southern
Telescopes would no less than revolutionize the astronomical
research on small bodies of the solar system. The Spaceguard
Foundation is currently looking for ways to establish the
telescopes on Gamsberg, Namibia. It is noted that the United
Nations Workshops on Basic Space Sciences held over the past few
years have passed resolutions calling for (i) A global network of
small telescopes for NEO search, tracking and other observations;
and (ii) The establishment of a major inter-African observatory
and
science park in Namibia.
==========================================================================
ITEM 7: JAPANESE ACTIVITY ON NEOS
The Spaceguard Association of Japan (a private organization) was
officially founded on October 20, 1996, and it now has nearly 300
members including professional scientists and members of the
public. A regular scientific meeting is held every alternate
month,
and public lectures are to be given several times per year,
beginning in August after IAU GA. In addition, an information
bulletin in published once every three monthes, and all suitable
NEO information is posted on the Spaceguard Japan WWW homepage
(hhtp://www.crl.go.jp/ka/control/asteroid/SGFJ/), making this
information freely available to non-members.
There are two major projects for which funding is being sought.
The
first of these is a pair of one-meter class ground-based
telescopes
to be located in Japan. It appears that the Japanese government
views this project favorably, and we are hopeful that the budget
will be approved next August. These telescopes would be used both
for NEO studies and for observations of space debris.
The second project concerns a lunar-based NEO telescope. The
NASDA
(Japanese national space agency) has plans to launch several
lunar
missions beginning in 2003. The first mission is nearly totally
defined. We are discussing with NASDA the possibility of having
the
second mission include a 30 cm NEO telescope as a site test
instrument to the other main instrument, with a launch in 2005.
If
this project were to go ahead, it would be viewed as being a
trial
for a larger (one-meter class) lunar-based NEO telescope in the
future.
Japan is also involved in direct spacecraft investigations of
NEOs.
The Muses-C spaceprobe is being built by ISAS (Institute of Space
and Astronautic Sciences) for launch on a M-5 rocket in 2002, the
mission entailing a rendezvous with the near-Earth asteroid
(4660)
Nereus, a sample of that asteroid being returned to the Earth in
2006. ISAS is collaborating with NASA on this program.
==========================================================================
ITEM 8: NEO ACTION IN THE UNITED KINGDOM
Spaceguard UK was established on 1 January 1997, with aims
designed
to complement those of the Spaceguard Foundation, but with a
distinct national emphasis. Throughout 1996 the foundations of
the
organisation were laid, making contacts and consulting with many
of
the key players worldwide culminating in June with the
presentation
of a paper on the NEO threat to the British government. The most
significant result was a major meeting of interested parties,
representatives of many scientific establishments and government
departments in November 1996. The meeting decided to establish a
UK
NEO Working Group that will be meeting for the first time in July
1997. Spaceguard UK itself is a growing organisation. Dr Arthur C
Clarke and Dr Patrick Moore have both agreed to become Trustee
members, though the title will probably change due to the legal
implications of the term "trustee". Already there are
over a dozen
Associate members, including Dr Duncan Steel, Professor Mark
Bailey, Professor Tony McDonnell, Dr Bill Napier, Dr Victor
Clube,
Dr Benny Peiser and Dr Michael Martin-Smith. General membership
stands at nearly fifty, with two "corporate" members,
"Meteor"
magazine and the Society for Popular Astronomy. We have a new
government in the UK, and a political campaign is planned for the
late summer and autumn with the aim of establishing a formal,
government-sponsored NEO programme. 1996 was a highly successful
year, and 1997 promises much.
The Spaceguard UK home page is:
http://dspace.dial.pipex.com/town/terrace/fr77/
Jay Tate
==========================================================================
ITEM 9: SPACEGUARD IN GERMANY
There is now an affiliate of The Spaceguard Foundation in
Germany.
For information see the home page:
http://spaceguard.dlr.de/sgf/SGFhome_eng.html
==========================================================================
ITEM 10: NEO SEARCH AND TRACKING TELESCOPES PLANNED IN SOUTH
AMERICA
A consortium of astronomers from Argentina, Brazil and Uruguay
are
planning the development of telescopes with aperture around one
meter dedicated to searching for, and tracking, NEOs. The likely
site for the search telescope is in western Argentina, with two
follow-up telescopes in Brazil and Uruguay. For information
contact
Gonzalo Tancredi (gonzalo@fisica.edu.uy) or see
http://www.fisica.edu.uy/PAGES/gonzalo/research.html
==========================================================================
Not all components of these messages will be positive; we feel
that
the The Spaceguard Foundation also has a responsibility to report
on developments which reflect negatively upon the general aim of
the foundation.
==========================================================================
ITEM 11: AUSTRALIAN INACTIVITY
The program on NEO search and tracking in Australia, which was
the
only such program in the southern hemisphere, terminated last
December 31st due to the cessation of funding. This was an
important program largely because it delivered astrometric
observations of NEOs in regions of the sky inaccessible from the
north, this being especially significant for newly-discovered
NEOs
moving south. For example, of 463 NEAs known at the end of 1996,
about 300 were large enough and had well-enough defined orbits to
allow some confidence of their telescopic recovery; of those, 119
were observed astrometrically by the Australian team (McNaught,
Garradd, Steel) during 1996. In addition, the team has over the
years made many important precoveries of NEOs; for example,
within
a week of the discovery of Comet Hale-Bopp in 1995 July, a faint
image of the comet was found on a U.K. Schmidt Telescope plate
exposed in 1993 April, indicating that the comet was active
whilst
at a very large heliocentric distance (and thus massive, as has
proven to be the case), and also that the comet was not a new
comet
in the Oort cloud sense, instead having an orbital period of a
few
thousand years. The termination of the Australian NEO program has
meant that such searches of old Schmidt plates are no longer
carried out.
Various news media around the world reported in early April a
statement by an Australian government minister to the effect that
the government was looking at ways by which the program might be
revived. This announcement has misled many people in other
nations
working on NEOs. At the time of writing in mid-May, the
Australian
government has not been in contact with the team mentioned above
in
order to discuss whether the program might be re-started; indeed,
the press release was issued when it was known that Steel and
McNaught were out of the country, and so unable to be contacted
by
the Australian media.
==========================================================================
ITEM 12: NEW ZEALAND INACTIVITY
With the termination of the Australian NEO program, there is an
added need for other southern hemisphere observatories to fill
the
gap which is left. Recently a question was asked in the New
Zealand
parliament with regard to whether NZ is involved in observations
of
NEAs. The answer given by the government minister was misleading,
in that it was said that the program which used to be operated at
Mount John University Observatory by Alan Gilmore and Pam
Kilmartin
(who is a member of the Minor Planet Naming Committee) was
"uncompetitive" since it used photographic detection.
In fact,
with no other routine southern hemisphere NEO tracking program in
operation, there is no competition. One could envision a
situation
whereby a NEA making a close passage by the Earth and found by
one
of the US search programs might be lost, whereas a single
photographic detection from NZ might secure its orbit. New
Zealand,
due to its latitude and longitude, and the experience and
expertise of Kilmartin and Gilmore, must be a member of any
international Spaceguard program. Further, we note that for a
small nation like New Zealand (population three million) there
are
few ways in which the country can become a full member of any
large
space program, except by providing ground-based services such as
those required for Spaceguard. Apart from the technological and
scientific benefits, we note that the involvement of such nations
as participants in space programs rather than merely as
spectators
must be inspirational and motivational to their youth, leading to
more able students directing their studies towards engineering,
technology, and science.
==========================================================================
ITEM 13: BOOK REVIEW IN NEW SCIENTIST MAGAZINE
The following is provided without comment from The Spaceguard
Foundation (except to note that clearly we are, in general,
unable
to agree with what is stated below between the quotation marks).
We also note that Gene Shoemaker, a member of the Board of
Directors of The Spaceguard Foundation, was the Chair of the NASA
committee in question.
The issue of NEW SCIENTIST (London) dated 3 May 1997 contains a
review on pp.46-47 by John Casti of the Santa Fe Institute (New
Mexico) of the book "Cartographies of Danger: Mapping
Hazards in
America" by Mark Monmonier (University of Chicago Press).
Casti
writes the following, inter alia:
"Maps of risk can also be dangerously misleading or
erroneously
interpreted to serve a political agenda. A good example in the
latter category is NASA's 1993 map of ancient asteroid
collisions,
produced in an effort to persuade Congress to part with $50
million
to study a high-tech defence against colliding asteroids. To
convince Washington to cough up the money for a network of
satellites and early-warning telescopes so that astronomers could
catalogue such threatening objects and forecast collisions with
Earth, NASA tried to document the magnitude of the threat with a
map showing 130 terrestrial impact craters.
What the map says is that asteroids, comets, and large meteorites
have struck the Earth many times over the past 2 billion years,
with a clear implication that they can strike again. So far, so
good. In fact, the map very likely understates the threat, since
many such impacts have probably occurred in the sea and in
jungles,
where evidence is hard to come by.
What makes the NASA map absurd is not the impacts it shows, but
the
implication that there is something that we can do to prevent an
impact in the future, should NASA's programme have detected an
asteroid on a collision course. Even with a Reagan-style Stars
[sic] Wars defence system, the likelihood of effectively
destroying
or diverting such a bolide is negligible. Here, a valid hazard
map
was used to serve a political agenda that cannot deliver what it
claims."
==========================================================================
(END OF MESSAGE FROM THE SPACEGUARD FOUNDATION)