OSETI III Press Release
The Search for Extraterrestrial Intelligence
in the Optical Spectrum III
SPIE, the International Society for Optical Engineering, will host the third conference on The Search for Extraterrestrial Intelligence in the Optical Spectrum III (OSETI III). This will be part of the Photonics West Symposium which is being held at the San Jose Convention Center, San Jose, California, in January 2001. The two previous Optical SETI conferences were held in 1993 and 1996. This third international conference is the largest so far, and is scheduled for January 22-24, 2001. The OSETI III conference is complementary to the Free-Space Laser Communication Technologies XIII Conference, which will be held on January 24-25. The keynote speaker for OSETI III will be Britain's Professor Chandra Wickramasinghe who will present a paper on The Unity of Cosmic Life and the Inevitability of Evolved Life Forms. This paper is co-authored with Professor, Sir Fred Hoyle.
Optical SETI involves a search for laser signals that may have been targeted
at our planet by extraterrestrial civilizations located around nearby stars. The
search rationale involves looking for continuous wave attention-getting laser
beacon signals or very short laser pulses. Searching for pulsed laser signals is
the more popular rationale, since it can be shown that short laser pulses can
substantially exceed the brightness of a star during each flash, and therefore
could be easily separated and detected above the stellar background noise.
It is expected that there will be a total of about 30 papers and 4 posters, covering a variety of SETI-related topics, though the emphasis is on the optical search for extraterrestrial intelligence. The 2001 OSETI III conference is highlighted by a special invited paper, which is to be presented by Nobel Laureate, Professor Charles H. Townes. His paper on Reflections on Forty Years of Optical SETI -- Looking Forward and Looking Backward, will mark the 40th anniversary of Optical SETI. Dr. Jill Tarter will present a paper on SETI 2020: A Roadmap for Future SETI Observing Projects. Professor Ron Bracewell, keynoter for the 1996 OSETI II Conference, returns with a talk on Imaging Nonsolar Planets by Nulling Interferometry. Professor Paul Horowitz will speak about the Targeted and All-Sky Search for Nanosecond Optical Pulses at Harvard/Smithsonian and Monte Ross will describe The PhotonStar Project - a kind of optical version of the peer-to-peer (P2P) SETI@Home Project that has proved extremely popular over the past year and a half. Professor Allen Tough will discuss Widening the Range of Search Strategies, and on a more down-to-earth note, Dr. Hamid Hemmati will present an Overview of Laser-Communications Research at NASA/JPL.
For up-to-date information about the conference schedule, visit: www.coseti.org/4273-sch.htm. There is a reduced registration fee for registering online before January 9, 2001. For general information about Optical SETI, visit: www.coseti.org. See also the December 2000 issue of Astronomy Now.
These are just some of the papers scheduled to be presented at the OSETI III Conference. For more extensive information about the conference, abstracts of papers and how to register, visit www.coseti.org/spiepro3.htm. The meeting will be concluded by another performance of SETI Songs by Dr. Paul Shuch of the SETI League, and a workshop panel. The latter will discuss the conference presentations and where we go from here.
Dr. Stuart A. Kingsley
Dr. Ragbir Bhathal
First Posted: October 10, 2000
In 1965, Monte Ross suggested that looking for very short duration ETI laser beacon signals of about 1 ns duration would be a sensible strategy. The main advantages of the short pulsed laser beacon approach is that during each pulse, it is very easy to make the beacon signal much brighter than the stellar background of the ETI's star, so that the detected pulse is many orders of magnitude brighter than the background star. In addition, it is not necessary to substantially pre-filter the incoming photon flux - the optical detectors can be operated in their full intrinsic optical bandwidth. Thus, there is no need to guess the magic optical frequency or laser transition. It is only necessary to guess that part of the electromagnetic spectrum that is likely to be used by ETIs for this form of interstellar communications. This substantially reduces the search space and search time.
With the right type of telescope and equipment, Optical SETI observations can actually be done during the day under a clear blue sky and night-sky light pollution has little effect! Further, it is not even necessary to use diffraction limited optics for the receivers. Large, low-cost, non-diffraction limited photon light-bucket mirrors may be employed to collect the photons. The general Optical SETI strategy is to conduct a targeted search and look at the same solar-type stars that are the subject of the microwave search. This involves initially observing some 800 to 1,000 stars out to a range of about 100 light years and then a million stars out to a range of about 1,000 light years.
In 1973, the NASA Project Cyclops Report, which today is often referred to as the "SETI Bible", wasn't very kind to OSETI as a means for interstellar communications, and as a result, for over a quarter of a century little was done to officially promote the optical approach, particularly in the United States. Most Optical SETI observations during the 70's and 80's were carried out by the Soviet scientists, Shvartsman and Beskin. Today, the preferred type of Optical SETI in the visible and near infrared regions of the electromagnetic spectrum, is to look for short pulses with a pair of ultra-fast photomultipliers or solid-state avalanche photodetectors operating in a coincidence mode. Optical SETI research may be conducted with both large and small optical telescopes. This is an activity in which amateur optical astronomers can participate and will likely lead to a renascence in amateur optical astronomy. Both Microwave and Optical SETI should be seen as a natural part of the Space Program. Sad to say, both SETI fields are still subject to the "giggle factor" amongst more conservative scientists and engineers, though fortunately, less so today than in earlier decades.