NAOJ seminar by Robert G Strom

You can download the related paper from the following URL.

https://dl.dropboxusercontent.com/u/50942940/We_Are_Not_Alone.pdf

Dear colleagues, ------------------------------ NAOJ Seminar 天文台談話会 ------------------------------ 第946回　6月14日 (火)　16:00-17:00　大セミナー室 No.946: June 14, Tue. 16:00-17:00 Large Seminar Room Speaker: Robert G Strom (University of Arizona) Title: "Are We Alone? Extraterrestrial Technological Life in Our Galaxy" Abstract: An evaluation of the number of technological civilizations presently in our Milky Way galaxy is discussed. The current estimate of the present number of Earth-like planets (+/-25% of Earth’s radius) in the habitable region of Sun-like stars is about 6.6 billion. Using a modified Drake Equation, "optimistic", "pessimistic" and "unlikely" estimates of six constraints indicate that about 40,000 technological civilizations are presently in our galaxy for a "pessimistic evaluation". Even "unlikely" values that are half the "pessimistic" values give over 600 technological civilizations in the galaxy. It would take a completely unrealistic value of 2.5% for each constraint to get just 1 technology (us). Therefore, we are almost surely not alone in our Milky Way galaxy. Furthermore, almost all of the extra-solar system technologies are probably much further advanced than ours, i.e. they probably began thousands to millions of years before our Industrial Revolution. ---------------------------------------------------------------- NAOJ Seminar is usually held at 4 pm on Friday. Everyone is welcome to attend. If you are interested in giving a seminar, please contact one of us (T. Yano, T. Takiwaki, M. Kubo, Y. Matsuda, T. Akutsu and S. Ishii).