|
Preface
On July 31, 2003, the Transition Panel for the Hubble
Space Telescope/James Webb Space Telescope issued a report on the
scientific impact of the current NASA plan for ending HST operations and
beginning JWST operations. The panel requested further comments from the
scientific community.
The open letter that follows concerns
the retrofit of the HST for
Optical SETI (OSETI) and the design of the JWST to incorporate the
capability of undertaking OSETI.
To see why it is important to have space-based Optical
SETI observatories one only has to consider the spectral window presented
by Earth's atmosphere. The atmospheric
transmission chart presented
here covers the approximate wavelength range of the James-Webb Space
Telescope. Not shown is the ultra-violet band between 0.3 microns and 0.1
microns which is blocked by Earth's
atmosphere but is available to the Hubble Space Telescope. These two
telescopes together provide a complementary means to access a substantial
and contiguous range of optical frequencies.
On a more philosophical note, it is distressing to read that NASA has
given up on the idea of eventually bringing the HST back to Earth for display in the Smithsonian or
parking it in a higher orbit for safety, but would rather send it
crashing back to Earth in a controlled
re-entry at the end of this decade. This is pure vandalism. It is rather like suggesting that if the original
Santa Maria was on display in a
museum in Spain and while towing it to the New World for display here it
accidentally sank, we would make no attempt to retrieve it.
Our descendants would not think much of this generation if we did not
leave them the legacy of the Hubble Space Telescope to marvel at. Even
if we were not ready for the HST to undertake OSETI in this decade, by
parking it safely in a higher orbit, we would ensure its availability
later both for OSETI and its eventual display in the Smithsonian, after
the Space Shuttle is replaced by a more
reliable space vehicle.
If you agree to the importance for the HST and JWST to be equipped to undertake OSETI
observations, please contact Professor Bahcall and/or the NASA
Administrator, Dr. Sean O'Keefe at NASA Headquarters. In particular, you
are encouraged to contact NASA about this matter, whether you are a
scientist, engineer, a concerned member of
the public, or just a citizen of Planet Earth. 2010 should not mark
the end of the HST but a new beginning.
Dr. Sean O'Keefe
Administrator,
Room: 9F44,
NASA Headquarters
Washington DC 20546-0001
United States
sokeefe@mail.hq.nasa.gov
Tel: 1-202-358-1010
Fax: 1-202-358-2810
Paragraph added on November 18, 2003
As a result of the official response to this letter (see the link near
bottom of page for this correspondence) which was dated November 14, 2003,
it was clear that there had been a mis-communication about the type of
OSETI I was proposing. I had not considered doing an All-Sky
Diffraction-Limited Survey with either the HST or JWST. Indeed, the
necessity of conducting an All-Sky Survey was a red-herring made in 1990
by the late Bernard Oliver, then Deputy SETI
Chief of NASA's SETI Office. Dr. Oliver referred to this as being
"the crux of the matter". If professional astronomers should come
across this page, perhaps they might now consider submitting proposals to
NASA addressing natural fast optical phenomena!
James Webb Space Telescope (JWST)
The Letter:
November 2, 2003
Professor John N. Bahcall
Chair, HST-JWST Transition Panel
Institute for Advanced Study
School of Natural Sciences
Princeton, NJ, USA
jnb@ias.edu
Space-Based Optical SETI for HST and JWST
Summary
This letter recommends that the Hubble Space
Telescope and the James Webb Space Telescope be adapted to the Search for
Extraterrestrial Intelligence in the Optical Spectrum (Optical SETI) by
equipping them with fast photon-counters. The optical spectrum
covered by the HST and the JWST provide an extraordinary wide
complimentary window for the detection of ETI laser beacons signals not
available to ground-based Optical SETI (OSETI) observatories. Since
1998, major ground-based Optical SETI observatories have been set up, but
as with Microwave SETI, the results to date have been negative. It
would be a major oversight not to plan conducting space-based OSETI
observations with these two great telescopes, particularly if by 2010,
ground-based OSETI observatories have failed to detect either
monochromatic continuous wave or short pulsed laser beacon signals.
Dear Professor Bahcall,
My name is Dr. Stuart A. Kingsley.
Research scientists in the SETI community know me as the person who, for
the past thirteen years, has been the strongest proponent for the
Optical Search for Extraterrestrial Intelligence, otherwise known as
Optical SETI or OSETI.
Please excuse me for being a bit late in
making my contribution to the debate on the plans for HST and JWST. I
was on extended leave for family reasons in the United Kingdom at the
time your report on the HST-JWST Transition Panel findings was
published.
To my knowledge, it appears that the idea of retrofitting the HST for
Optical SETI and incorporating the capability of undertaking OSETI with
the JWST has not been discussed, or at least not considered to be of
sufficient priority to warrant a mention. This is despite the fact that
the father of Optical SETI, Professor Charles H. Townes, is a member of
your transition panel (please see this reference:
http://www.coseti.org/4273-05award.htm).
From the years 1993 through 2001, I arranged
three SPIE International Society for Optical Engineering conferences on
Optical SETI. The keynote speakers for the 1993, 1996, and 2001
conferences were Arthur C. Clarke, Ronald Bracewell, and Chandra
Wickramasinghe, respectively.
Since the early 1990s, I have made it known, both
from my Web site (http://www.coseti.org)
and at the OSETI conferences, that I would like to see the HST equipped
for OSETI. I have also recommended that serious thought be given to incorporating the equipment
into the formerly named Next Generation
Space Telescope (NGST).
Hubble's mirror
system is usable over the wavelength range of approximately 110 nm to
1100 nm. The present specifications for the James Webb mirror system
calls for a response over the wavelength band of 600 nm to > 10,000 nm.
The extended spectral range in the ultra-violet
for the Hubble Space Telescope and the extended infrared range
for the James Webb Space Telescope, opens up a much larger window for
Continuous Wave (CW) and Pulsed-Type OSETI than is possible for
ground-based observatories.
Incidentally, my
colleague, Monte Ross (http://www.coseti.org/ross_00.htm),
pioneered the use of very short pulsed laser signals for both free-space
laser communications and Optical SETI. Monte literally "wrote the book"
on free-space laser comms and one of the
first text books in the modern field of photonics. Monte and I are
presently involved with the so-called PhotonStar
Project (http://www.photonstar.org),
which is an optical version of SETI@Home,
but with the major difference that each individual OSETI astronomer
collects his or her own data
and sends data via the Internet to a
central computer for correlation. All telescopes are aimed at the
same star system at the same time.
I strongly request the panel and NASA to give serious consideration
to equipping both telescopes with photon-counting systems to cover as
much of the spectral range as possible within the limits of the
state-of-the-art in photon-counting technology with time resolution
capabilities down to 1 ns. The coincident photon-counting head approach
pioneered by Professor Towne's colleagues at Berkeley, Harvard, and
other OSETI groups, could share common signal processing electronics to
cover the required spectral regions. The high-resolution spectrographs
already incorporated in the telescopes will do fine for the
monochromatic (CW) beacon type of OSETI searches.
Just equipping the HST and JWST with ultra-fast photon-counting
capabilities is bound, by serendipity, to lead to new discoveries of
natural ultra-fast phenomena occurring in the
Universe.
The following references contain my quotes
from two of the publications that can be found on my Web site.
The EJASA article that first promulgated the concept of OSETI on the
Internet: “The Search for Extraterrestrial Intelligence (SETI) in the
Optical Spectrum" in The Electronic
Journal of The Astronomical Society of the Atlantic (EJASA), Volume
3, Number 6, January, 1992 (http://www.coseti.org/ejasa_09.htm#mature).
The following statement is from page 58:
"We cannot even be sure that ETIs
would want their signals to be detected within an atmosphere or
otherwise too easily. These are prevalent assumptions among most SETI
proponents. There might be logical reasons for ETIs to think that only
when a technical civilization begins to "emerge" from its planet would
it be truly mature enough, and in a culturally receptive frame of mind,
to receive signals from ETIs. Thus, the recipients' atmosphere itself
might be used as an automatic protective blanket to avoid cultural
shock. In a way, the electromagnetic search for ETI is one of the
greatest hunts and detective stories ever. Unfortunately, there are
still so few clues."
The second reference quote comes from the OSETI II conference, "A
Prototype Optical SETI Observatory," Proceedings of SPIE's 1996
Symposium on Lasers and Integrated Optoelectronics, Photonics West '96,
The Search for Extraterrestrial Intelligence (SETI) in the Optical
Spectrum II, Vol. 2704, San Jose, California, January 27-February 2,
1996, pp. 102-116 (http://www.coseti.org/paper_05.htm):
"It is the author's present belief that as far as interstellar
electromagnetic communications are concerned, only targeted free-space
laser communications can sustain the signal-to-noise ratio, and the low
interstellar dispersion and scintillation effects, so as to convey
wideband, Gbit/s type data links over hundreds or thousands of light
years. Using microwave transmitters to "broadcast" signals across
interstellar space is very inefficient, and cannot support wideband
communications due to insufficient signal-to-noise ratio, and
significant interstellar dispersion and scintillation effects.
A negative outcome of a visible SETI search would not imply that ETIs do not exist or use lasers, but merely that their laser
transmissions may be in the infrared or far-infrared, even at
wavelengths to which the atmosphere is not transparent. It may well
be that space-based receivers will be required for successful reception
of SETI signals. The atmospheres of the intended targeted planets
might be used as a safety blanket to delay successful reception of the
signals until the targeted civilization was mature enough to have
developed space-based technologies, and presumably, be in a better
condition to avoid catastrophic effects from too early a cultural
contamination."
There is a further comment in the chair and co-chair's introduction
to the 1996 OSETI II proceedings, which may be found at
http://www.coseti.org/2704-int.htm. Space-Based Optical SETI is described
on page 89 of my paper "Optical SETI Observatories in the new
Millennium: A Review," The Proceedings of SPIE's 1996 Symposium on
Lasers and Integrated Optoelectronics, Photonics West '96, The Search
for Extraterrestrial Intelligence (SETI) in the Optical Spectrum III,
Vol. 4273, San Jose, California, January 22-24, 2001, pp. 72-91. A link
to a PDF file of the full paper may be found on the abstract page
http://www.coseti.org/4273-08.htm. One concept not discussed in
that paper is the possibility that the International Space Station (ISS)
could also deploy relatively small telescopes to conduct space-based
Optical SETI.
Information related to promoting space-based OSETI may also be found
on my Web site on the following pages:
·
http://www.coseti.org/spacetel.htm
· http://www.coseti.org/4273-20.htm. Paper by Steven Kilston & David
L. Begley of Ball Aerospace, solicited for the OSETI III conference held
in 2001. A link to a PDF file of the full paper may be found on that
abstract page. The citation for that paper is as follows:
"Next-Generation Space Telescope (NGST) and Space-Based Optical SETI,"
The Proceedings of SPIE's 1996 Symposium on Lasers and Integrated
Optoelectronics, Photonics West '96, The Search for Extraterrestrial
Intelligence (SETI) in the Optical Spectrum III, Vol. 4273, San
Jose, California, January 22-24, 2001, pp. 136-143.
The discoveries that HST has yet to make may well exceed the
discoveries made to date. The Electromagnetic Search for
Extraterrestrial Intelligence is surely an important component of NASA's
"Origins Program". Wouldn't be ironic if the HST was the first
telescope to discover intelligent life elsewhere in the
Cosmos. It is surely a concept that
would re-invigorate the public's
interest in the HST and astronomy and space
exploration in general.
It has taken eight years of lobbying
on my part, mainly through a series of OSETI conferences and the COSETI
Web site, to get the mainstream SETI community to rethink the
rationale for Microwave SETI and realize that the Optical approach also has considerable merit. It has taken nearly forty years for
Schwartz and Townes classic paper to be recognized by the scientific
community as a major milestone in the search for ETI. Let us hope that
it will not take nearly as long for NASA
to realize that space-based OSETI's time has come.
I look forward to receiving your responses on this matter. I would
be glad to expand further on these OSETI concepts for the two telescopes
at your request.
Sincerely,
Dr. Stuart A. Kingsley
Director, The Columbus Optical SETI Observatory &
The Bournemouth
Optical SETI Observatory (UK)
SPIE's Optical SETI Conference Chair
www.coseti.org
www.boseti.org
This open letter has been posted to the
COSETI Web site at:
www.coseti.org/hst-jwst.htm
NASA's Reply
|
