The Search for Extraterrestrial Life: Recent Developments Interna Tional Astronomical Union Union Astronomique Internationale

THE SEARCH FOR EXTRATERRESTRIAL LIFE: RECENT DEVELOPMENTS INTERNA TIONAL ASTRONOMICAL UNION UNION ASTRONOMIQUE INTERNATIONALE

THE SEARCH FOR EXTRATERRESTRIAL LIFE: RECENT DEVELOPMENTS

PROCEEDINGS OF THE 112TH SYMPOSIUM OF THE INTERNA TlONAL ASTRONOMICAL UNION HELD AT BOSTON UNIVERSITY, BOSTON, MASS., U.S.A., JUNE 18-21,1984

EDITED BY

MICHAEL D. PAPAGIANNIS Department of Astronomy, Boston University, Boston, Mass., U.S.A.

D. REIDEL PUBLISHING COMPANY

A MEMBER OF THE KLUWER ACADEMIC PUBLISHERS GROUP

DORDRECHT/BOSTON/LANCASTER/TOKYO library of Congress Cataloging in Publication Data

International Astronomical Union. Symposium (112th: 1984: Boston University) The search for extraterrestrial life - recent developments.

Includes index. 1. Life on other planets-Congresses. I. Papagiannis, Michael D., 1932- II. Title. QB54.I57 1984 574.999 85-18282

ISBN-13: 978-90-277-2114-3 e-ISBN-13: 978-94-009-5462-5 DOl: 10.1007/978-94-009-5462-5

Published on behalf of the International Astronomical Union by D. Reidel Publishing Company, P. 0. Box 17, 3300 AA Dordrecht, Holland

Sold and distributed in the U.S.A. and Canada by Kluwer Academic Publishers, 190 Old Derby Street, Hingham, MA 02043, U.S.A.

In all other countries, sold and distributed by Kluwer Academic Publishers Group, P. O. Box 322, 3300 AH Dordrecht, Holland

No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical, in.eluding photocopying, recording or by any information storage and retrieval system, without written permission from the publisher. A C K NOW LED GEM E N T S

IAU Commission 51 expresses its deep appreciation to the:

INTERNATIONAL ASTRONOMICAL UNION (IAU) NATIONAL AERONAUTICS AND SPACE ADMINISTRATION (NASA) BOSTON UNIVERSITY (B.U.) for their generous financial and moral support, which made possible this first IAU Symposium of our new lAU Commission.

D E D I CAT ION

I would like to dedicate this Volume to my mother

MS. THEMITSA PAPAGIANNIS who follows with love from Greece all the work we do.

v ORGANIZING COMMISSION OF IAU SYMPOSIUM 112

IAU COMMISSION 51 - SEARCH FOR EXTRATERRESTRIAL LIFE

COSPONSORING IAU COMMISSIONS

NO. 15 - PHYSICAL STUDY OF COMETS, MINOR PLANETS AND METEORITES NO. 16 - PHYSICAL STUDY OF PLANETS NO. 24 - PHOTOGRAPHIC ASTROMETRY NO. 40 - RADIO ASTRONOMY

COSPONSORING INTERNATIONAL ORGANIZATIONS

COSPAR (ICSU COMMITTEE OF SPACE RESEARCH) IAF/IAA (INTERN. ASTRONAUT. FED./ INTERN. ACAD. OF ASTRONAUT.) ISSOL (INTERN. SOCIETY FOR THE STUDY OF THE ORIGIN OF LIFE) IUBS (INTERNATIONAL UNION OF BIOLOGICAL SCIENCES) TABLE OF CONTENTS

ACKNOWLEDGEMENTS AND DEDICATION ...... v

SYMPOSIUM ORGANIZATION' ~~ COSPONSORSHIPS ...... vi SCIENTIFIC ORGANIZING COMMITTEE &LOCAL ORGANIZING COMMITTEE ...... xiii LIST OF PARTICIPANTS ...... xv PREFACE, M.D. Papagiannis ...... xix FIGURE 1, Morrison holding commemorative plaque with Papagiannis and Drake ...... xxiii FIGURE 2, Purcell, Morrison, Sagan, Papagiannis, and Drake at the Symposium Banquet ...... xxv

SECTION I. HISTORY AND SPECIAL EVENTS ...... 1

INTRODUCTION, The Editor ...... 3 A HISTORICAL INTRODUCTION TO THE SEARCH FOR EXTRATERRESTRIAL LIFE, Michael D. Papagiannis ...... 5 TWENTY-FIVE YEARS OF THE SEARCH FOR EXTRATERRESTRIAL COMMUNICATIONS, Philip Morrison.: ...... 13 SETI IS COMING OF AGE, Giuseppe Cocconi ...... 21 WELCOMING ADDRESS, Arthur G.B. Metcalf ...... 23 INVOCATION, Bishop Demetrios Trakatellis ...... 25

SECTION II. THE SEARCH FOR OTHER PLANETARY SySTEMS ...... 27

INTRODUCTION, The Editor ...... 29 viii TABLE OF CONTENTS A REVIEW OF THE SCIENTIFIC RATIONALE AND METHODS USED IN THE SEARCH FOR OTHER PLANETARY SYSTEMS, David C. Black ...... 33 PROTOPLANETARY MATERIAL AROUND NEARBY STARS, Hartmut H. Aumann ...... 43 ON THE NUMBER OF GALACTIC PLANETARY SYSTEMS, Steven Beckwith ...... 51 PLANETARY SEARCHES USING OPTICAL ASTROMETRIC INTERFEROMETERS, D.H. Staelin, M.M. Colavita, and M.Shao ...... 59 A NEW OBJECTIVE FOR THE ALLEGHENY OBSERVATORY 30-INCH REFRACTOR, G.D. Gatewood, J.K. de Jonge, J. Stein, and C. DiFatta ...... 65 PROSPECTS FOR SPACE TELESCOPE IN THE SEARCH FOR OTHER PLANETARY SYSTEMS, J.L. RusselL ...... 75 DETECTING DISTANT PLANETS WITH SPACE TELESCOPE, Thornton Page ...... 85 ABSOLUTE ASTRONOMICAL ACCELEROMETRY: A NEW TOOL FOR PLANETARY SEARCHING, Pierre Connes ...... 91 ASSISTING EXTRASOLAR PLANETARY DETECTION THROUGH THE DETERMINATION OF STELLAR SPACE ORIENTATIONS, Laurance R. Doyle ...... 97

SECTION III. PLANETARY, INTERPLANETARY AND INTERSTELLAR ORGANIC MATTER ...... '...... 101

INTRODUCTION, The Editor ...... 103 TITAN'S ORGANIC CHEMISTRY, C. Sagan, W.R. Thompson, and B. N. Khare ...... 107 PREBIOTIC MATTER IN INTERSTELLAR MOLECULES, Ronald D. Brown ...... 123 RECENT OBSERVATIONS OF ORGANIC MOLECULES IN NEARBY COLD, DARK INTERSTELLAR CLOUDS, H. Suzuki, M. Ohishi, M. Morimoto, N. Kaifu, P. Friberg, W.M. Irvine, H.E. Matthews, and S. Saito ...... 139 INFRARED SPECTRAL IDENTIFICATION OF COMPLEX ORGANIC MOLECULES IN INTERSTELLAR GRAINS, J. Mayo Greenberg and Willem Schutte ...... 145 UNIVERSAL PROTEIN ANCESTORS FROM HYDROGEN CYANIDE AND WATER, Clifford N. Matthews ...... •...... 151 PANSPERMIA - A MODERN ASTROPHYSICAL AND BIOLOGICAL APPROACH, J. Mayo Greenberg and Peter Weber ...... 157 TABLE OF CONTENTS ix NO VALID EVIDENCE EXISTS FOR INTERSTELLAR PROTEINS, BACTERIA, ETC, R.E. Davies, A.M. Delluva, and R.H. Koch ...... 165 ASTRONOMICAL SOURCES OF CIRCULARLY POLARIZED LIGHT AND THEIR ROLE IN DETERMINING MOLECULAR CHIRALITY ON EARTH, Ramon D.. Wolstencroft ...... 171 SECTION IV. UNIVERSAL ASPECTS OF BIOLOGICAL EVOLUTION ...... 177

INTRODUCTION, The Edi tor ...... 179 SYNTHESIS AND ANALYSIS IN CHEMICAL EVOLUTION, Cyril Ponnamperuma .... 185 MOLECULAR REPLICATION, Leslie E. Orgel ...... 199 THE PRECAMBRIAN EVOLUTION OF TERRESTRIAL LIFE, Andrew H. Knoll ...... 201 HUMAN EVOLUTION: THE VIEW FROM SATURN, Misia Landau ...... 213 SOME IMPLICATIONS OF MASS EXTINCTION FOR THE EVOLUTION OF COMPLEX LIFE, J. John Sepkoski, Jr ...... 223 EVIDENCE FOR A SOLAR COMPANION STAR, Richard A. Muller ...... 233 THE UNIVERSAL DIAGRAMS AND LIFE IN THE UNIVERSE, Minas Kafatos ...... 245 UNIVERSAL ASPECTS OF BIOLOGICAL EVOWTION, John A. Bal1...... 251 ON THE OCCURRENCE AND APPEARANCE OF GALACTIC LIFE FORMS: A THERMODYNAMIC APPROACH, G. Bodifee and C. de Loore ...... 255

SECTION V. RADIO SEARCHES - RECENT OBSERVATIONS ...... 261

INTRODUCTION, The Editor ...... 263 SETI OBSERVATIONS WORLDWIDE, Jill Tarter ...... 271 PROJECT SENTINEL: ULTRA-NARROWBAND SETI AT HARVARD/SMITHSONIAN, Paul Horowitz and John Forster ...... 291 THE OHIO SETI PROGRAM - THE FIRST DECADE, Robert S. Dixon ...... 305 A SEARCH IN THE INFRARED TO MICROWAVE FOR ASTROENGINEERING ACTIVITY, V.I. Slysh ...... 315 x TABLE OF CONTENTS SEARCH FOR STRONGLY POLARIZED RADIO EMISSION FROM E.T.I., AND AN OPTIMIST APPROACH TO THE GREAT SILENCE (FERMI'S PARADOX) , J.P. Vallee ...... 321 LUNAR REFLECTIONS OF TERRESTRIAL RADIO LEAKAGE, Woodruff T. Sullivan, III and Stephen H. Knowles ...... 327 EAVESDROPPING DETECTION OF RADIO SIGNALS FROM OTHER PLANETS WITH ONE BIT IMPLEMENTATION TECHNIQUES USING EXISTING COMPUTERS, Stephen H. Knowles ...... 3.35

SECTION VI. TECHNOLOGICAL PROGRESS IN RADIO SEARCHES ...... 341

INTRODUCTION, The Editor ...... 343 SET!: A MORE ECLECTIC APPROACH, Bernard M. Oliver ...... 351 THE 8-MILLION CHANNEL NARROWBAND ANALYZER, Paul Horowitz, John Forster, and Ivan Linscott ...... 361 THE MULTICHANNEL SPECTRUM ANALYZER, A.M. Peterson, K.S. Chen, and I.R. Linscott ...... 373 SOFTWARE IMPLEMENTATION OF DETECTION ALGORITHMS FOR THE MCSA, D. Kent Cullers ...... 385 SETI: THE MICROWAVE SEARCH PROBLEM AND THE TARGETED SEARCH APPROACH, Charles L. Seeger and John H. Wolfe ...... 391 SETI: THE MICROWAVE SEARCH PROBLEM AND THE NASA SKY SURVEY APPROACH, Michael J. Klein and Samuel Gulkis ...... 397 AN ANALYSIS OF THE ELEMENTS OF AN ALL SKY SURVEY, Edward T. Olsen, Anatoly Lokshin, and Samuel Gulkis ...... 405 OPTIMUM SEARCH STRATEGY FOR RANDOMLY DISTRIBUTED CW TRANSMITTERS, Samuel Gulkis ...... 411 A MILKY WAY SEARCH STRATEGY FOR EXTRATERRESTRIAL INTELLIGENCE, Woodruff T. Sullivan, III, and Kenneth·J. Mighell ...... 419 THE SERENDIP II DESIGN, Dan Werthimer, Jill Tarter, Stuart Bowyer ... 421 NEW 45M RADIO TELESCOPE AND FOURIER-TRANSFORM TYPE SPECTROMETER AT NOBEYAMA RADIO OBSERVATORY, Hisashi Hirabayashi ...... 425 TABLE OF CONTENTS xi SECTION VII. THE FERMI PARADOX AND ALTERNATIVE SEARCH STRATEGIES ... 435

INTRODUCTION, The Editor ...... 437 A COMPARATIVE ANALYSIS OF SPACE COLONIZATION ENTERPRISES, Frank D. Drake ...... 443 ON THE QUESTION OF INTERSTELLAR TRAVEL, John H. Wolfe ...... 449 EXPONENTIAL EXPANSION: GALACTIC DESTINY OR TECHNOLOGICAL HUBRIS?, Ben R. Finney ...... 455 WHERE ARE THEY? IMPLICATIONS OF ANCIENT AND FUTURE MIGRATIONS, Eric M. Jones ...... 465 GALACTIC COLONIZATION AND COMPETITION IN A YOUNG GALACTIC DISK, Edwin L. Turner ...... 477 EXTRATERRESTRIAL INTELLIGENCE: WHERE IS EVERYBODY?, John A. BalL .. .483 FERMI QUESTION, FERMI PARADOX: ONE HIT, ONE OUT, Char les L. Seeger ...... 487 ON A COSMIC ALPHABET, D. Hoang-Binh ...... 493 ON THE INEVITABILITY AND THE POSSIBLE STRUCTURES OF SUPERCIVILIZATIONS, Nikolai S. Kardashev ...... ' ...... 497 AN INFRARED SEARCH IN OUR SOLAR SYSTEM AS PART OF A MORE FLEXIBLE SEARCH STRATEGY, Michael D. Papagiannis ...... 505

SECTION VIII. SUMMARIES, COMMENTS AND CONCLUSIONS ...... 513

INTRODUCTION, The Editor ...... 515 SUMMARY OF SESSION I. fHE SEARCH FOR PLANETS AROUND OTHER STARS, George D. Gatewood ...... 523 SUMMARY OF SESSION II. PLANETARY, INTERPLANETARY AND INTERSTELLAR ORGANIC MATTER, William M. Irvine ...... 527 SUMMARY OF SESSION III. UNIVERSAL ASPECTS OF BIOLOGICAL EVOLUTION, John Billingham ...... 529 QUESTIONMARKS REMAINING, George Marx ...... 535 TWO ADDITIONAL COMMENTS, John A. Ball ...... 539 xii TABLE OF CONTENTS A LOOK INTO THE FUTURE, Michael D. Papagiannis ...... 543

CONCLUDING REMARKS, Harlan J. Smith ...... 547 ACTIVITIES AND RESOLUTIONS OF IAU COMMISSION 51, Michael D. Papagiannis ...... 553 EPILOGUE, Michael D. Papagiannis ...... 557 INDEX ...... 561 SCIENTIFIC ORGANIZING COMITTEE

MICHAEL D. PAPAGIANNIS, USA, Chairman. JOHN BILLINGHAM, USA, Representing NASA. DONALD DEVINCENZI, USA, Representing COSPAR. FRANK D. DRAKE, USA.

JUN JUGAKU, JAPAN. NIKOLAI S. KARDASHEV, USSR. GEORGE MARX, HUNGARY. RUDOLF PESEK, CZECHOSLOVAKIA, Representing IAF/IAA. CYRIL PONNAMPERUMA, USA/SRI LANKA, Representing ISSOL. CARL SAGAN, USA.

OTTO SOLBRIG, USA, Repre~enting IUBS. V.S. TROITSKY, USSR.

LOCAL ORGANIZING COMMITTEE

PHILIP MORRISON, MIT, Co-Chairman EDWARD M. PURCELL, Harvard University, Co-Chairman TOM BANIA, Boston University STEPHEN JAY GOULD, Harvard University PAUL HOROWITZ, Harvard University EDWARD LILLEY, Harvard University MICHAEL D. PAPAGIANNIS, Boston University DAVID STAELIN, MIT

xiiii LIST OF SYMPOSIUM PARTICIPANTS AND CONTRIBUTORS TO THIS VOLUME

AARONS J., Boston University, Boston MA, USA. AUMANN H.H., Jet Propulsion Laboratory, Pasadena CA, USA.

BALL J .A., Harvard College Observatory, Cambridge MA, USA. BANIA T.M., Boston University, Boston MA, USA. BANNI STER G.. Boston University, Boston MA. USA. BECKWITH S., Cornell University, Ithaca ~Ty, USA. BILLINGHAM J., NASA-Ames Research Center, Moffett Field CA, USA. BLACK D., NASA-Ames Research Center, Moffett Field CA, USA. BODIFEE G., Free University, Brussels, BELGIUM. BEATTY J. K. , Sky and Telescope, Cambridge MA, USA. BOUMIL J. S . , Lowe 11 MA, USA. BOVt'YER S., University of California, Berkeley CA, USA. BOYCE P .B. , American Astronomical Society, Washington, DC, USA. BROWN R.D., Monash University, Clayton Victoria, AUSTRALIA. BUCK L., Omni Magazine, New York, NY, USA.

CARR J., Charles Hayden Planetarium, Boston MA, USA. CARR T.D., University of Florida, Gainesville FL, USA. CHANDLER D. L. , Boston Globe, Boston MA, USA. CHASAN B. , Boston Lini versi ty, Boston MA, USA. CHEN K.S. , Stanford University, Stanford CA. USA. CHOU K. C. , Kyung Bee University, Seoul, S. KOREA. CHOU B.J., Kyung Bee University, Seoul, S. KOREA. CLOUGHERTY J. V . , Sharon MA, USA. COCCONI G., CERN. Geneva, SWITZERLAND. COLAVITA M.M., MIT, Cambridge MA, USA. CONNES P., CNRS-Service d'Aeronomie, Verrieres, FRANCE. COOKE R. W. , Boston Globe, Boston MA, USA. COWEN R. C., Christian Science Monitor, Boston MA, USA. CREASE R., Atlantic Magazine, Boston MA, USA. CULLERS K.D., NASA-Ames Research Laboratory, Moffett Field CA, USA. DAVIES R.E., University of Pennsylvania, Philadelphia PA, USA. DE JONGE J.K., Allegheny Observatory, Pittsburgh PA. USA. DE LOORE C.W.B., Free Uni versi ty, Brussels, BELGIUM. DEGOL B., Mrs. C. De Loore, Brusse Is. BELGIUM. DELLUVA A.M., University of Pennsylvania. Philadelphia PA, USA. DEVINCENZI D., NASA Headquarters, Washington DC, USA. DIFATTA C., Allegheny Observatory, Pittsburgh PA, USA. DIXON R.S., Ohio State University, Columbus DB, USA. DOYLE L., NASA-Ames Research Center, Moffett Field CA, USA. xv xvi LIST OF PARTICIPANTS

DRAKE F .D., University of California, Santa Cruz CA, USA. DRAPER C.S., C.H. Draper Laboratory, Cambridge MA, USA. DRUYAN A., Cornell University, Ithaca NY, USA. ECCLES M. J . , Burr-Brown Ltd, Edinburgh. Scotland, U.K. FELDMAN P. A. , Herzberg Institute of Astrophysics, Ottawa, CANADA. FIELD C.A., Uni vers i ty of Massachusetts, .Amherst MA, USA. FINNEGAN T.A. Allegheny Observatory, Pittsburgh PA, USA. FINNEY B.R., University of Hawaii, Honolulu HA, USA. FIRNEIS F. J. , Austrian Academy of Sciences, Vienna, AUSTRIA FORSTER J., Harvard Univ., Proj. Sentinel, Cambridge MA, USA. FOWLER K. J . , Parkville MD, USA. FRIEBERG P. , University of Massachusetts, Amherst MA, USA. GATEWOOD G., Allegheny Observatory, Pittsburgh PA, USA. GLASHAW S., Harvard University, Cambridge MA, USA. GOLDSMITH D. , Interstellar Media, Berkeley CA, USA. GOULD S.J., Harvard University, Cambridge MA, USA. GREENBERG J. M. , University of Leiden, Leiden, HOLLAND. GRINSPOON D., Boston MA, USA. GULKIS S., Jet Propulsion Laboratory, Pasadena CA, USA. HEIDMANN J., Observatoire de Paris, Meudon, FRANCE. HIRABA YASH I H., Nobeyama Radio Observatory, Nobeyama, Nagano, JAPAN. HUGHES W. J . , Boston University, Boston MA, USA. HOANG- BINH D., Observatoire de Paris, Meudon, FRANCE. HOROWITZ P. , Harvard University, Cambridge MA, USA. IRVINE W.M., University of Massachusets, Amherst MA, USA.

JANES K.A., Boston University, Boston MA, USA. JONES E.M., Los Alamos National Lab., Los Alamos NM, USA. JONES K.M., W. Tisburg MA, USA. JUGAKU J., Tokyo Astron. Observatory, Mitaka-shi, Tokyo, JAPAN. KAFATOS M. , George Mason University, Fairfax VA, USA. KAIFU N., Nobeyama Radio Observatory, Nobeyama, JAPAN. KARDASHEV N. S . , Space Res. Inst., Academy of Sciences, Moscow, USSR. KENNEDAL D. , Stockholm Observatory, Saltsjobaden, SWEDEN. KIMBALL R.L., Taipei American School, Taipei, TAIWAN. KHARE B.N., Cornell University, Ithaca NY, USA. KLEIN M.J., Jet Propulsion Laboratory, Pasadena CA, USA. KNOLL A.H., Harvard University, Cambridge MA, USA. KNOLL M. , Mrs. A. Knoll, Cambridge MA, USA. KNOWLES S., Naval Research Laboratory, Washington DC, USA. KOCH R.B., University of Pennsylvania, Philadelphia PA, USA. KOCH J .C., Mrs. R.H. Koch, Philadelphia PA, USA. KRAUSS J., Ohio State University, Columbus OH, USA. KRAUSS A., Mrs J. Krauss, Columbus OH, USA. LIST OF PARTICIPANTS xvii

LANDAU M., Boston University, Boston MA, USA. LILLEY E., Harvard-Smithsonian CFA, Cambridge MA, USA. LINSCOTT I., Stanford University, Stanford CA, USA. LOKSHIN A., Jet Propulsion Laboratory, Pasadena CA, USA. LORD S.D., University of Massachusetts. Amherst MA, USA. LORE D., Columbus Dispatch, Columbus OH, USA. LYON D., Boston University, Boston MA, USA. MALLOVE E., Lincoln Labs, Bedford MA, USA. MANN C., Atlantic Magazine, Boston MA, USA. MARDUS F., University of Guadalajara, Guadalajara, MEXICO. MARDUS E., Mrs. F. Mardus, Guadalajara, MEXICO. MARGULIS L., Boston University, Boston MA, USA. MARX G., Eotvos University, Budapest, HUNGARY. MATTHEWS C. N. , University of Illinois, Chicago IL, USA. MENDILLO M., Boston University, Boston MA, USA. METCALF A. G. B.. Electronics Corporation of America, Cambridge MA, USA. MCDONOUGH T. R. , Planetary Society & Caltech, Pasadena CA, USA. MIGHELL, K.J. University of Washington, Seattle WA, USA. MIRABEL I.F., University of Puerto Rico, Rio Piedras, PUERTO RICO. MOON J. H. , Cambrian College, Sudbury ONT, OANADA. MORIMOTO M., Nobeyama Radio Observatory, Nobeyama, Nagano, JAPAN. MORRISON P. , MIT, Cambridge MA, USA. MORRISON P. , Mrs P. Morrison, Cambridge MA, USA. MULLER R.A., University of California, Berkeley CA, USA. NICHOLS R., Boston's Museum of Science, Boston MA, USA. OHISHI M., Nobeyama Radio Observatory, Nobeyama, Nagano, JAPAN. OLIVER B.M., NASA-Ames Research Center', Moffett Field CA, USA. OLSEN E. T. , Jet Propulsion Laboratory, Pasadena CA, USA. ORGEL L.E., The Salk Inst. of Biolog. Studies, San Diego CA, USA. OVERBYE D., Discover Magazine. New York NY, USA. PADULO L. Boston Unviersity, Boston MA, USA. PAGE T., NASA-Johnson Space Center, Houston TX, USA. PAPAGIANNIS M.D. Boston University, Boston MA, USA. PESEK R., Czechoslovak Academy of Sci., Prague, CZECHOSLOVAKIA. PETERSON A. M. , Stanford University, Stanford CA, USA. PONNAMPERUMA C., Univ. of Maryland, College Park MD, USA/SRI LANKA. PURCELL E.M., Harvard University, Cambridge MA, USA. QUIRK M.D., Jet Propulsion Laboratory, Pasadena CA, USA. REINERTSEN S., University of California, Berkeley CA, USA. ROBINSON L., Sky and Telescope, Cambridge MA, USA. RUSSELL J.L., Space Telescope Science Institute, Baltimore MD, USA. RUSSELL R., Boston Globe, Boston MA, USA. SAGAN C., Cornell University, Ithaca NY, USA. SAITO S., Institute for Molecular Science, Okazaki, JAPAN. xviii LIST OF PARTICIPANTS SCHILD H., Geneva Observatory, Sauverny, SWITZERLAND. SCHLITZKUS W., Framingham MA, USA. SCHUTTE W., University of Leiden, Leiden, HOLLAND. SEEGER C., NASA-Ames Research Center. Moffett Field CA, USA. SEPKO SKI J. Jr. , University of Chicago, Chicago IL, USA. SHAD M. , Smithsonian Astrophys. observ., Cambridge MA, USA. SIMARD-NORMANDIN Herzberg Inst. for Astrophysics, Ottawa oNT, CANADA. SLYSH V. 1. , Space Res. Inst., Academy of Sciences, Moscow, USSR. SMITH H. J., University of Texas, Austin TX, USA. SMITH J. S . G. , Mrs. H. Smith, Austin TX, USA. SoLBRIG 0., Harvard University, Cambridge MA, USA. SoRESEN J .E., Boston MA, USA. STAELIN D., MIT, Cambridge MA, USA. STEFANIK R.P., Boston University, Boston MA, USA. STEIN J. W., Allegheny obsevatory, Pittsburgh PA, USA. STEIN J.K., Mrs. J. Stein, Pittsburgh PA, USA. SULLIVAN W. , New York Times, New York NY, USA. SULLIVAN W.T.III, University of Washington, Seattle WA, USA. SUZUKI H., Nobeyama Radio Observatory, Nobeyama, Nagano, JAPAN. TARTER J., NASA-Ames Research Center, Moffett Field CA, USA. THOMSEN D.E., Science News, Washington DC, USA. THOMPSON W. R. , Cornell University, Ithaca NY, USA. TOLBERT C. R. , University of Virginia, Charlottesville VA, USA. TRAKATELLIS D., Bishop of Vresthena, Archdioces of Athens, GREECE. TRoITKSY V. S . , Radiophys. Res. Inst., Gorky State Univ., Gorky, USSR. TURNER E.L., Princeton University, Princeton NJ, USA. VALLEE J.P., Herzberg Inst. for Astrophysics, Ottawa ONT, CANADA. VERRIFKEN A. M. , Mrs. G. Bodifee, Brussells, BELGIUM. WEBB W., Charles Hayden Planetarium, Boston MA, USA. WEBER P., University of Leiden, Leiden. HOLLAND. WERTHIMER D., University of California, Berkeley CA, USA. WOLFE J .H., NASA-Ames Research Center, Moffett Field CA, USA. WoLSTENCRoFT R.D. Royal Observatory, Edinburgh Scotland, U.K. PREFACE PROCEEDINGS IAU S)1WOSIUM 112

Michael D. Papagiannis Department of Astronomy Boston University Boston, Massachusetts 02215, USA

1. THE SYMPOSIUM AND THE PROCEEDINGS

IAU Symposium 112 - The Search for Extraterrestrial Life: Recent Developments, was held in Boston and in particular at the new Science Center of Boston University, June 18-21, 1984, and was attended by about 150 participants from 18 different countries. It was the first official scientific meeting organized by IAti Commission 51, the youngest of all IAU Commissions, which was established only in 1982 at the 18-th IAU General Assembly at Patras, Greece. This Volume of the Proceedings contains nearly 70 papers with about 90 authors from 20 different countries, including two papers from our Soviet colleagues (Kardashev and Slysh) who had not been able to attend our Symposium in Boston. The Volume is divided into eight Sections, the first of which serves as a general introduction, and the other seven correspond to the seven Sessions of the Symposium. Since this was the first IAU Symposium in this new field, I have tried to make this Volume as complete and as readable as possible. I delayed its publication by several months to assure that extensive review articles by world authorities, and articles representing the state of the art in the search for planets, in the radio searches and ln the development of new instrumentation, were included in this Volume. I have also written extensive introductions for each one of the eight Sections to provide helpful background in the corresponding area. Each Introduction includes also a summary of the key points addressed by the papers of that Section. In this manner a non-specialist would be able to get a good introduction to the different multi-disciplinary aspects of this new field by simply reading.Section ] and the Introductions to the other seven Sections, i.e., a total of about 60 pages. After that it· would be much easier to read and understand the more specialized papers contained in this Volume. It is my hope that this arrangement will make this Volume friendlier to many more people who are not specialists but have a genuine interest in this new interdisciplinary branch of Astronomy, which is rapidly becoming known with the new term Bioastronomy.

xix xx M. D. PAPAGIANNIS

2. THE ORGANIZATION OF THIS VOLUME

Section I serves as an introduction to the entire Volume. Jyt Mst.arts with a historical review of the development of this new field b Papagiannis, followed by individual papers by P. Morrison and G. Cocconi, the two pioneers who ushered in the experimental era of the Search for Extraterrestrial Intelligence (SETI) with their historic paper to NATURE in 19S9. Since our Symposium coincided with the 25-th anniversary of their paper, we organized a special event at Boston's Museum of Science where Prof. Morrison was the key speaker and we honored him with a commemorative plaque (Figure 1). Section I contains also addresses from the Symposium Banquet, which was attended by many of the pioneers (Figure 2). Carl Sagan was the banquet speaker, and we honored him too for his many contributions in the explorations of our Solar System and his efforts to save our planet from a nuclear holocaust. The seven Sections that follow (II - VIII) represent a natural sequence of steps in the search for extraterrestrial life, both primitive and advanced. Planets seem t.o be the cosmic wombs and nurseries where life originates and evolves. Section II, therefore, is devoted to the search for other planetary systems. This is a key area where unfortunately we still know very little, but where impressive developments have occurred in the recent years, especially with the IRAS data, and where exciting progress is expected to occur in the next 10 - 20 years. Chemical evolution is the formation of complex organic compounds of importance to life from simple gases (methane, ammonia, water vapor, etc.) under a variety of natural conditions and environments. Their presence brings us a step closer to life and therefore Section III covers our searches for organic compounds. The results show that chemical evolution is a common phenomenon both in our Solar System and in interstellar space. I Section IV deals with the origin and evolution of life on Earth, the only example we know. The facts here are that life started very early, essentially as soon as the Earth was capable of holding it, but it took very long (nearly 4 billion years) to evolve to an advanced civilization. Does it always take that long? How do spurious or periodic externally induced effects, such as mass extinctions, affect the rate of biological evolution? Does the phenomenon of convergence, which we observe on Earth, has a universal validity? These are some of the questions that we discussed that are of great importance to our searches, and which w~ are still trying to understand from the only example of life in the Universe we know. Section V deals with our searches for radio signals from other advanced civilizations. The publication of this Volume coincides with the 2S-th anniversary of the first radio search, the celebrated Project OZMA, conducted by Frank Drake in 1960. Nearly 50 searches have been undertaken in these 25 years, logging close to 120,000 hours of observations. The sophistication of these searches has been increasing at a rapid pace, as has also the international participation. PREFACE

Section VI covers recent technological developments and the plans for the future. They include the construction of a new generation of multichannel spectrum analyzers with eight million channels and the development of special signal recognition algorithms for the on-line detection of a variety of signals. The NASA SET I Program. which will conduct comprehensive targeted and all-sky searches over a wide (1 - 10 GHz) frequency range, is now in the development stage and is expected to become operational toward the end of the decade of the 1980's. Section VII addresses the controversy that surrounds the question of galactic colonization and the apparent absence of extraterrestrials from the Earth. A happy message that emerges from this Section and permeated our entire meeting was the general consensus that experimental work, and not debates, is the only way to resolve our questions, and therefore our search strategy ought to be broad and flexible enough to allow also for the experimental testing of different theoretical alternatives. Section VIII is the last Section of this Volume and tries to summarize what has been achieved so far and what are the long term prospects. It is quite clear that tremendous progress has been achieved in these past 25 years, including scientific recognition, interdisciplinary collaboration, international participation, hours devoted to searches, funding, number of people involved, technological innovations, etc. In his first search in 1960, Frank Drake used a receiver with a single channel, the frequency of which was continuously changed to cover the spectral range around the hydrogen line. By comparison, we are now getting ready to embark on radio searches using spectrum analyzers with 8 million channels. We can be proud of what has been accomplished in the past 25 years and may look with considerable confidence and optimism toward the next 25 years when many of the more advanced searches for planetary systems, organic compounds, and radio signals will be implemented.

3. PERSONAL ACKNOWLEDGEMENTS

I want to express my personal appreciation to the many people who helped me with the organization of the Symposium and with the preparation of this Volume. This is not an easy task because there are indeed many people to thank whose help and support made this whole effort possible. I would like to start with President John R. Silber of Boston University and thank him for his strong support and for the allocation of University funds for our Symposium. Dr. A.G.B. Metcalf, the Chairman of the University's Board of Trustees for representing Boston University at the Symposium and for his kind words in his Welcoming Address. Dr. Geoffrey Bannister, the Dean of the College of Liberal Arts and the Graduate School for hosting a fine welcoming reception for all the Symposium participants and for his persona) support. My colleagues in the Astronomy Department, Drs. K. Janes, M. Mendillo, K. Brecher, J. Aarons, J. Hughes, A. Marscher and especially Tom Bania and Bob Stefanik for their invaluable help with the many organizational tasks of the Symposium. Also Bishop Demetrios Trakatellis for his inspirational xxii M. D. PAPAGIANNIS

Invocation at the Banquet, and Dr. Gene Ma10ve of Lincoln Labs who was also of great help with the running of t.he Symposium. I am deeply indebted to the Executive Committee of the IAU and especially to its General Secretary Dr. Richard West and its Assistant General Secretary Dr. J.P. Swings for the financial support they provided for the Symposium, and for their persona] encouragement at many difficult moments. I am also grateful to NASA and especially to Drs. Donald DeVincenzi, John Billingham and Bernard Oliver for NASA's financial support of the Symposium and for their useful advice and personal help both at the Symposium and with the Proceedings. I want to thank Frank Drake and Carl Sagan who helped me start the planning of the scientific sessions of the Symposium at my trip to Cornell in the fall of 1983, and Carl Sagan especially for agreeing to be our Banquet Speaker. I am also grateful to Dr. Roger Nichols, the Director of Boston's Museum of Sceince, and to Mr. Jack Carr, the Director of its Hayden Planetarium, for organizing our very successful special event at the Museum of Science, and to Dr. Philip Morrison for his eloquent and inspiring talk at this event. My appreciation to all the members of the Scientific Organizing Committee and of the Local Organizing Committee of the Symposium for their help and support. Also to the Presidents of IAU Commissions 15, 16, 24 and 40, and of the International Organizations COSPAR, IAFjlAA, ISSOL and IUBS for co-sponsoring our Symposium. I want to thank also Drs. C. Sagan, J. Jugaku, W. Irvine, D. DeVincenzi, L. Margulis, J. Billingham, E. Purcell, E. Lilley, F. Drake, G. Marx, P. Morrison, and H. Smith who chaired the Sessions of the Symposium. Also to the many distinguished scientists from all around the world who presented important papers at the Symposium and sent their contributions for the Proceedings. I hope they will all forgive me for any pressure I might have exercised when time for the Proceedings was' getting short. I am grateful to my good friend Dr. George Marx for offering to organize the next lAC Symposium of our Commission 51 in Hungary in the summer of 1987, and to Drs. N.S. Kardashev, V.I. Slysh and V.S. Troitsky for their warm hospitality during my visit to Moscow right after our IAU Symposium and for sending me their contributions for the Proceedings in spite of the fact that they were not able to attend our Symposium. I want to express my deep appreciation to our Librarian, Ms. Fenn Duncan, who did most of the typing in the word processor for this Volume, which with all the Introductions I wrote and the several papers that needed to be retyped amounted to more than 100 pages. Also to our Administrative Assistant Ms. Cecilia Piccolo, and to the Curator of our Planetarium Mr. David Bradford for their great help both during the Symposium and in the completion of this Volume. I am also grateful to the many people in the Housing, Conferences, and Food Services departments of Boston University who did a splendid job during our Symposium. Finally I want to thank Mrs. N.M. Pols - v.d. Heijden of the D. Reidel Publishing Co. for her support and for her patience in the preparation of these Proceedings of IAU Symposium 112. I hope we have all labored for a good and worthy cause. AD ASTRA PER ASPERA. FIGURE 1. Professor Philip Morrison holding the plaque with which he was honored by lAU Commission 51 during its recent IAU Symposium in Boston . The event commemorated the 25 years from the 1959 publication of his and Cocconi ' s pioneering paper in Nature. To his right is the President of lAU Commission 51 Professor Michael D. Papagiannis, and to his left is its Vice President, Professor Frank D. Drake, who was also the first to carry out in 1960 the Search proposed by Cocconi and Morrison . FIGURE 2. A group of prominent lAU Symposium 112 participants, from the Symposium Banquet. From left to right: Edward M. Purcell, Nobel laureate, co-discoverer of the 21 em hydrogen line; Philip Morrison, co-author of the 1959 pioneering paper on SETl that ushered the experimental era; Carl Sagan, distinguished scientist and author, Banquet speaker; Michael D. Papagiannis, President of lAU Commission 51 and organizer of the Symposium; Frank D. Drake, conducted the first radio search (Project Ozma, 1960), and Vice President of IAli Commission 51.

xxv