COMPLEMENTARY DOCUMENT 10 RESPONSES TO A QUESTIONNAIRE SENT TO LEADING RADIO OBSERVATORIES Prepared by: Philip Morrison Massachusetts Institute of Technology RESPONSES TO A QUESTIONNAIRE SENT TO LEADING RADIO OBSERVATORIES At the conclusion of the second full meeting of the Workshop, it was agreed to survey the directors of representative radio observatories on a number of matters where the apparent direction of SETI and the concerns of those observatories overlapped strongly, especially in the utility of wide-band simultaneous reception. The following letter was sent to about 35 such directors from the published lists. Seventeen answers were received from organizations in the United States and in three other countries. The responses to the questions are summarized below; the identity of the respondents is filed in the records of the Workshop. One foreign response included an original contribution to the problem; several other responses included reprints and other valuable information. Overall, we learned that there was not much unpublished work in SETI, and that most radio observatories could foresee some forms of cooperation between their ordinary scientific investigations and work on behalf of SETI. MASSACHUSETTS INSTITUTE OF TECHNOLOGY DEPARTMENT OF PHYSICS CAMBRIDGE. MASSACHUSETTS 02139 Room 6-308 August 29, 1975 Dear About fifteen years ago it first became clear that the normal development of the science of radio and radar astronomy had had an unexpected consequence: we humans found ourselves in actual possession of the means of signalling to an assumed counterpart installation across interstellar distances. То this day no other communications technique is capable of such a reach. though not to Whatever your That fact stimulated the proposal to listen transmit for such signals from elsewhere. estimate of the probability that there exist distant counterparts, possibly much advanced ones, of our technology, it is plain that eventual empirical tests of the conjecture imply interests parallel to the broader concerns of most radio astronomers. I write to draw upon that convergence of interest, to ask your help in hope of mutual advantage. A scientific working group has been established lately in the USA to examine and to report upon the question of a search for interstellar communications. I am currently Chairman of the group their names are listed below includes participants from a wide range of disciplines, astronomers with a wide variety of specialty, information and communications experts, biologists, experienced engineers. A somewhat similar effort to ours has lately been reported by a Board of the Academy of Sciences of the USSR (1). which It is premature to announce any decision on optimum channels and procedures, or on the scale of effort which makes sense. But we regard the frequency range from about 1 Ghz to a few tens of Ghz as a major candidate. That forms the basis of our mutual interest. Within this form of search, two or three distinct modes can be seen. The initial Soviet emphasis seems to be devoted to |