Dear friends,
Our sixth annual UCLA SETI course is off to a great start. We had our first Zoom meeting on Wednesday with 20 undergraduate students and 3 graduate students. There is gender parity and the following fields of study are represented: 10 physics (4 astrophysics, 3 geophysics), 7 engineering (5 electrical, 2 mechanical), 3 computer science, 2 math, and 1 astrobiology. I am fortunate that Paul Pinchuk and Robert Geil have agreed to assist with the course, just as they did last year. Their help makes a huge difference in the quality of the student experience. For instance, two students had trouble logging into the computer that we use for software development and data analysis. We quickly dispatched one student in a breakout room with Paul and the other student in a breakout room with Robert. Nobody was held back, and everyone reintegrated into the class a few minutes later when the problems were resolved. Observations for the SETI course are scheduled at the Green Bank Telescope on April 21, 2021 from 3 pm to 5 pm PDT.
The SETI Institute organized a contest at the January 2021 meeting of the American Astronomical Society that centered on answering the following question: "What does SETI Institute astronomer Seth Shostak say is the value of N in the Drake Equation?" Frank Drake defined N as the number of "civilizations [in the Milky Way Galaxy] of intelligent beings having and applying a technology sufficiently advanced to permit detection of the civilization over interstellar distances."
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The Drake Equation. Image credit: SETI Institute.
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The contestant with the closest answer would win SETI Institute swag. My wife, who regularly proofreads this newsletter, has an unbounded fondness for swag. I submitted an estimate of 9,000 and came closest to Seth's estimate, which is 10,000. The star formation rate in the Galaxy is a few solar masses per year, but most stars are less massive than the Sun, so I used 18 new stars per year (R*). The fraction of stars with planets is essentially 100% (fp). The mean number of planets with environments suitable for life in each planetary system is approximately 0.5 (nE). Things get a lot more speculative for the remaining factors in the equation. I assumed that life emerges on 10% of habitable planets (fl). I assumed that life becomes intelligent on 100% of life-bearing planets (fi) over cosmic timescales, which reflects an optimistic belief in the power of biological evolution and the evolutionary advantages conferred by intelligence. I assumed that 100% of planets bearing intelligent life give rise to a technology that is detectable over interstellar distances. Finally, I used an average lifetime for civilizations of 10,000 years (L), which Frank Drake and others have also adopted as a rough estimate. Note that contact could be established even if probabilities were much lower (e.g., fl = fi = fc = 0.1%), as long as a single civilization subsisted for a long time.
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Last December, MIT professor Sara Seager gave an astronomy colloquium at UCLA titled "The Search for Signs of Life Beyond Earth by Way of Atmospheric Biosignature Gases." During the Q&A portion of the colloquium, I asked whether she thought that the first convincing evidence for life elsewhere would come from the detection of biosignatures in the Solar System, biosignatures on exoplanets, or technosignatures. She pondered the question for a while and chose biosignatures in the Solar System. I have since proposed a scientific wager to her, in which I argue that technosignatures, rather than biosignatures, will provide the first convincing evidence of life elsewhere.
As you may know, the SETI community was deeply affected by the collapse of the Arecibo telescope on December 1, 2020. To me, the feeling of loss was magnified because I was a postdoc at Arecibo for two years and I had been using the Arecibo Planetary Radar for scientific investigations ever since. The New Yorker just published an article about the Arecibo Observatory, which leaves us with an extraordinary scientific legacy. This article highlights the role of Cornell University in the history of the telescope, including the pioneering work of William Gordon, who conceived the telescope, and the momentous work of Donald Campbell, who oversaw a major upgrade of the Observatory in the 1990s. It is worth mentioning some connections in this context: Don Campbell obtained his PhD at Cornell under the guidance of Frank Drake and I obtained my PhD at Cornell under Don's guidance. When Arecibo collapsed, I very much shared Don's grief.
Warm regards,
Jean-Luc Margot
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