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The Planetary Society is a nonprofit, non-governmental public-membership organization formed in 1979 by Carl Sagan, Bruce Murray, and Louis Friedman. It is the largest space-interest group in the world, with a membership of over 100,000.
In 1981, Senator Proxmire induced Congress to eliminate funding for the young NASA SETI program. The Planetary Society jumped into the breach, helping NASA scientists attend a SETI meeting in the USSR, and lobbying Congress to restore the NASA program. Together with NASA's efforts, this led to the reinstatement of NASA SETI.
At that time, the Society also learned of a proposal by Harvard physicist Paul Horowitz. While visiting the Ames Research Center, he and colleagues had designed on paper a portable 131,000 channel receiver system called Suitcase SETI. Following Bernard Oliver's recommendation, the Society provided start-up money, and with additional help from the NASA SETI program, it was built. Later, at the Harvard-Smithsonian Oak Ridge radio telescope, the Society sponsored its permanent installation, beginning the most advanced continuously operating SETI system on Earth.
Some other SETI-related projects the Society has aided include:
The Society's greatest effort continues to be at Harvard, and has included arranging a grant of $100,000 from director Steven Spielberg. These monies enabled the construction of an 8-million channel receiver called META, turned on in 1985.
Argentine researchers sponsored by the Society duplicated META at Harvard. META II began continuous operation in Argentina in 1990 under the direction of Raul Colomb and the Argentine Institute of Radioastronomy, using their 30 meter radiotelescope.
And now, the Society is co-sponsoring with NASA and the Bosack-Kruger Charitable Foundation the construction of the Harvard group's newest design: BETA, a 160-million channel, dual-beam receiver that uses the U.C. Berkeley megachannel spectrometer. Both META and BETA complement the NASA SETI strategy by combining the high resolution of the targeted search with the coverage of the sky survey. The Planetary Society is determined to do everything it can to increase planet Earth's probability of success with SETI.
McDonough is SETI Coordinator for The Planetary Society
In preparation for the Sky Survey element of NASA's SETI Microwave Observing Project, JPL has been assembling and testing a prototype system to search the skies for extraterrestrial signals. The heart of the Sky Survey Prototype System (SSPS) is a computer-controlled, 2-million channel, Wide Band Spectrum Analyzer (WBSA) which we use to examine 40 MHz of frequency bandwidth, breaking it up into 19 Hz bins. Special-purpose hardware and software pick out those bins where unusually high power levels indicate the possibility of a signal. In late January, the SSPS was installed at NASA's Deep Space Communications Complex at Goldstone, California, where it has undergone testing with a 26-meter diameter radio telescope and a temporary radio receiver system operating in the "protected" frequency band at 8400 MHz.
One important test is to ensure that we can properly control the antenna (sweeping it across the sky in a search pattern at 0.2 degrees per second, much faster than usual for such antennas). We also test the ability of our special-purpose hardware and software to pick potential signals out of the data stream, while at the same time rejecting man-made Radio Frequency Interference (RFI) and other spurious signals. All this is under computer control because of the size, complexity, and speed of the system. While testing is still underway, preliminary results indicate that the SSPS is working extremely well.
A particularly valuable test involves searching a patch of the sky in which there is a known source of narrowband radio emission: one of NASA's own spacecraft. By "discovering" our own spacecraft while operating the system as if performing an actual SETI search, we not only test our ability to reject false signals caused by RFI or thermal noise (static), we can also confirm our capability for finding real signals. So far, we have detected Magellan, Ulysses, and Voyager. The SSPS picked up all three spacecraft at the correct location, signal strength, and frequency.
The small amount of RFI present in our current "protected" frequency band is rejected by the system, and the "false alarm" rate due to thermal noise agrees with theoretical predictions at the 1% level. After 3 months in the field, we have identified a number of possible improvements, but things are proceeding very well, and we expect to be ready on time to inaugurate the Sky Survey observations in October.
Levin is an Integration and Test Scientist at JPLIn early June, our roving reporter spoke with Dr. Peter Backus, who is one of the Principal Investigators for the Targeted Search half of NASA's Microwave Observing Project. His queries, and Backus' replies, are given here, and provide an insider's insights into last-minute M.O.P. developments.
Q. Is the Project advancing well towards the inauguration of observations this Fall?
A. I think we're making a great deal of progress in getting ready to begin observations in October at Arecibo. A lot of people are putting in long hours and working out all of the little bugs that crop up as you try and make very complex systems come together. Right now, considerable effort is being focused on getting reliable data transfer between the MCSA (MultiChannel Spectrum Analyzer) and the signal detectors, and this is the most critical part of the system. It has the highest data bandwidth. And those data have to be transferred in a certain format and with high reliability, so a lot of our efforts are directed there, but once we get through that I think the road is clear to Arecibo.
Q. Any other crucial areas?
A. Well, I think we are advancing well in all aspects of the project. The control software is able to communicate with all of the various hardware subsystems and exercise basic control of those systems. We're able to display data on the control computers. We're able to inject signals into the MCSA and have them displayed on the screen for testing. And once we get the data from the MCSA successfully transferred to the signal detectors, we'll essentially have a complete system that's ready for end-to-end testing.
Q. Has similar progress been made on the Sky Survey side of the Project?
A. The Sky Survey is actually a bit ahead of us. They are in the field, testing out their systems. Their main focus is on assuring themselves that they can accurately control the antennas at Goldstone. They have a very challenging goal there because they drive the antennas at such a high rate. They have to make sure they can command an antenna to move in a certain direction at a certain rate, and constantly know where the antenna is pointing. So, they're running through tests to verify that they can indeed control the antennas adequately. I've seen some of the results of the initial tests. They've been able to detect some spacecraft signals and test their signal detection algorithms using those spacecraft signals and everything seems to be working well.
Q. What is the most satisfying thing about the SETI Project to you?
A. There are a number of aspects that give me a feeling of satisfaction. Seeing this very advanced technology, the computer hardware and software coming together after so many years of design and development and a lot of hard work — that's very satisfying. But also realizing that in just a few months we'll be turning on the systems and beginning the search. We'll be accomplishing more than any other, or all other, SETI projects combined in literally the first minute that we operate. So it's kind of a two-part feeling of satisfaction: seeing things come together after so many years, and the anticipation that we're about to begin the search for real.
Arnold is a Research Assistant for the SETI InstituteMETA (Megachannel ExtraTerrestrial Assay) is the Planetary Society's current SETI project, carried out at twin sites in Massachusetts and Argentina (see accompanying article by Tom McDonough). Each site uses an 8.4 million-channel spectrum analyzer (400 kHz total bandwidth, 0.05 Hz resolution) and steerable dish antenna (84 foot at Harvard, 100 foot at Buenos Aires) to perform repetitive, all-sky searches, and could detect radio signals broadcast intentionally by a civilization like ours orbiting any of the nearest Sun-like stars. More advanced civilizations – with correspondingly more powerful transmitters – could make themselves detectable from the farthest corners of the Galaxy, which contains roughly 400 billion stars in a flattened disk 100,000 light years in diameter.
META is optimized for the detection of a radio beacon in the form of a carrier, technobabble that means a transmitter left on, but saying nothing! Though other sorts of signals are certainly reasonable, a carrier is particularly attractive because it is efficient, distinctly artificial, and can be distinguished from local interfering signals. Since its inauguration seven years ago by Steven Spielberg, META has patiently scanned the northern sky several times in the neighborhood of the celebrated 1420 MHz frequency of neutral hydrogen, and once near its second harmonic (2840 MHz). Its companion in Argentina is now completing the combined full-sky survey, including coordinated observations in the equatorial belt seen by both telescopes.
META's detection algorithms include compensation for the effects of rapid astronomical motions. In addition, it uses the unique signature of a changing radio frequency caused by Earth's rotation to discriminate a genuine cosmic signal from terrestrial interference. The good news is that these algorithms work – the search system has rejected almost entirely the radio mumblings (and bellows) of intelligent life on Earth. The bad news is obvious – we have made no detections!
BETA (Billion-channel ExtraTerrestrial Assay) is our planned next step, with additional sponsorship by NASA and the Bosack/Kruger foundation, and incorporating Berkeley's SERENDIP III spectrometer architecture. In its initial phase, we will use a dual-beam feed horn configuration, with 160 million-channel receiver, to search the full "waterhole" – the 300 MHz band of frequencies bounded by the dissociation products of water – in 50 MHz chunks: a later phase will break the billion-channel barrier for instantaneous coverage of the entire waterhole.
META and BETA are complementary to, not competitive with, the bold NASA initiatives now being readied for inauguration on Columbus day, 1992. In particular, they combine the high resolution of NASA's Targeted Search with the coverage of the Sky Survey, in a hunt for radio carriers alone. By thus giving up both frequency coverage and sensitivity to other kinds of signals, we can carry out a different kind of search, while keeping within the resources of university research.
Horowitz is a Physics Professor at Harvard UniversityThe creatures shown in the illustration are animals "evolved" by young students at Orion School (Redwood City, California). The young students selected from a "menu" of plausible, mutually compatible features to determine the size, numbers of limbs, habitats, reproductive features, internal anatomies and other properties of various animals. A similar activity develops a suite of plants. The result is a "planet" stocked with life forms that may be quite different from those of planet Earth. The organisms are then subjected to possible extermination by asteroid impacts, to geographic redistribution via continental drift, to additional "evolution" that hones their ecological relationships, and (eventually, for one species) to "evolutionary change" that results in intelligence.
How do elementary school students study evolution by hands-on activities? The preceding is one model devised by the staff of the SETI Science Curriculum Project for possible inclusion in the Teachers' Guides that the Project is developing. Another lesson in the same series has students examining protists, bacteria and flatworms, and then deciding which organisms are "more complex." Other lessons require them to draw lines connecting likely ancestors with descendants in an array of animal pictures spanning time from the Recent all the way back to the Precambrian, and stocking an "Earth History Aquarium" with blue-green algae, flatworms, plesiosaurs, and fish, all added or subtracted at the appropriate moments in a two month "Earth history" tracked by the class. (... plesiosaurs ? ... well ... their pictures, at any rate, taped to the back of the aquarium during "Mesozoic" time ... )
The evolution activities are examples of ways in which the SETI Science Curriculum lessons engage students in the learning of all sciences. The Curriculum Project is aimed at making elementary and middle school science classes exciting, hands-on, comprehensive, and affordable. The Teachers Guides, when finished, will be books of science activities like the above, all grounded on a topic – Life in the Universe– that is endlessly fascinating to young students. The activities are designed by teachers and NASA scientists, tested in classrooms, and revised and refined by the Project staff for further tests.
The activities have enjoyed enormous success. The students who created the animals shown above continued to refine them at home after school, and will never forget that some of their favorites (those weighing more than 50 lb) went extinct when the asteroid struck their planet. Teachers are now requesting the activities, even in their present, unfinished state. We'll continue to keep you posted on their development and availability. Meantime, we welcome your many valuable suggestions, and thank readers who responded to our previous article.
Milne is Science Education Coordinator at the SETI InstituteMuch has happened since the last issue of the SETI News. That article, originally "penned" in mid-October, focused on the solid fiscal year 1991 funding for the SETI Microwave Observing Project and the positive prospects for fiscal year 1992.
1992 activities were initially funded at a level of $13.5M (million). This represented a $1M reduction from the $14.5M requested by NASA. A congressional rescission action this spring (driven by attempts to lessen the federal deficit) further reduced the SETI appropriation by $1.25M, leaving a balance of $12.25M for the year.
In spite of these adverse funding developments, the engineering and science teams of the Targeted Search and Sky Survey have still managed to stay on schedule for the inauguration of the Project on October 12, 1992, the 500th anniversary of Columbus' discovery of the Americas. Everyone is to be commended for this accomplishment! Meeting the October 12 start date was critical in order that the Targeted Search would not lose over 200 hours of observing time scheduled during October and November, 1992 on the world's largest telescope in Arecibo, Puerto Rico. After November, that antenna will be down for two or more years for mechanical upgrades.
The 1992 funding shortfall, and the actions taken to deal with it while still meeting the inauguration date, make it doubly important to maintain the expected funding profile of $13.5M in fiscal year 1993. So, where does SETI stand in the congressional budget cycle for 1993? As is usual at this time of year, the picture is unclear. Indeed the situation is less certain than in the past few years. But there is reasonable hope for a positive outcome.
Backing for the project at NASA Headquarters remains strong. Recently appointed NASA Administrator Daniel Goldin has expressed strong interest in, and support for, the SETI Project. Dr. Lennard Fisk, Associate Administrator for the Office of Space Science and Applications, remains firmly committed to the Project. Everyone in Washington is working hard to see that SETI receives the funding necessary to do the job.
The 1993 NASA authorization bill (H.R. 4364) was considered by the House of Representatives on April 29, 1992. An amendment to this bill, introduced and passed by voice vote when very few members were present, deleted funding for SETI. Congressmen George Brown (D-Calif.), Robert Walker (R-Pa.), and Norman Mineta (D-Calif.) spoke strongly in opposition to the amendment, and were eloquent in their support of SETI. The authorization bill is now under consideration in the Senate. The ultimate fate of this bill will be determined later this year.
The 1993 NASA appropriations bill is, at the time of this writing, scheduled to go to the full committee of the House of Representatives on approximately July 23. The subcommittee has reported out a bill that does not include funds for SETI. Senate action on this bill will occur following passage of the bill by the House.
What is the prognosis? The negative actions in the early going of the 1993 funding process have all been based upon fiscal constraints and funding priorities in these tough budgetary times, and not upon the scientific, technical, and educational merits of SETI. We can only hope that, as in past years, the final result of this complicated process will be a strong endorsement of, and full funding for, SETI in FY 93.
HOW IS NASA SETI FINANCED?
Funding for NASA programs is the result of two bills that are passed into law each year: an authorization bill (establishing authority to spend) and an appropriation bill (providing actual money to spend). Both of these bills start out in the House of Representatives and, once passed there, go on to the Senate. In each body, the process involves subcommittee review and endorsement, full committee ratification, and floor approval. It inevitably is true that the bills, once passed by each house, are not identical. When this is the case, the bills are referred to "conference." At this time, members from both houses meet to reconcile the differences and agree on wording that can return to the floors of both houses for final ratification. After this occurs, the bill goes to the President for his signature.
Pierson is Director of the SETI InstituteIn my first column I briefly explained the role of the Investigators Working Group, the group charged with providing overall scientific direction to the NASA Microwave Observing Program (MOP). I also gave a sketch of our leader, Jill Tarter. This time I'd like to highlight our Deputy Project Scientist, Sam Gulkis of JPL. Sam is a radio astronomer who has primarily worked on the natural emissions from planets, but most recently he's been up to his neck in the exciting comological results pouring forth from the COBE satellite. The COBE team recently announced that they have detected minute variations in the intensity of the cosmic microwave background radiation that is the remnant of the very earliest times following the Big Bang. These variations have long eluded observers because they are so small (less than a part in 100,000) and difficult to calibrate. But their detection now should spur theorists to a much better understanding of how galaxies, stars, and (eventually) planets formed.
Sam heads up scientific direction for the Sky Survey portion of the MOP, and his careful approach to data acquisition and analysis is proving important in guaranteeing that the Sky Survey will achieve its intended sensitivity for intelligent signals, as well as for natural radio astronomy signals that we expect to receive as a bonus. The Survey will scan the entire sky over a broad range of microwave frequencies, and with unprecedented spectral detail (30 Hz resolution). The Sky Survey cannot detect signals as weak as those of the Targeted Search, but it is scanning the entire sky rather than focussing on only nearby stars – you pays your money and takes your choice. Even if no SETI signal should appear, the history of astronomy suggests that we have a high likelihood of discovering new natural radio phenomena, simply because we're looking at the sky in a way that has never been done before.
Sullivan is Professor of Astronomy at Washington University
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