SETI: Past , Present and Future

1. SETI: Past, Present and Future Iván Almár, Konkoly Observatory Hungary INAF Rome 25. Sept. 2019

2. „What’s past is prologue” Shakespeare (Tempest)

3. SETI: Past • Coldwarperiod – sixtyyearsago • Whyjustthe US and Russiastarted CETI? • Launch of Luna-3 and thefirstinterplanetaryspaceprobes • Firstcommunicationthroughinterplanetarydistances • Fermi paradox (1950)

4. Cooperationbetween American and Russianscientistsin CETI-SETI Shklovsky and Saganjointeffortfortheirbook „Intelligent Life intheUniverse” (1966) • The role of Ambarcumjan, Shklovsky, Kardashev, Sagan, Drake, Bernard Oliver tomaintaincooperation; • American-RussianjointconferencesByurakan (1971), Tallin (1981), Santa Cruz (1991)

5. Orthodox SETI • Radio searches in the water hole for narrow signals (messages) from solar type stars; „Big Ear”, HRMS, Phoenix, META... • „…look for what’s detectable, not for what’s probable.” (Dyson) • Recently: targeted search connected with Earth-like planets in habitable zones.

6. Radioastronomy: microwavewindowradioastronomy SETI @ home Arecibo (SERENDIP) Parkes radiotelescope

7. Radiotelesope arrays ATA Allen Telescope Array

8. SETI Decision Graph EM Microwave Receive Beacon Pulse CW Sequential Many antennas Coherent Many beams Signal processing Billingham

9. Opticalastronomy (laser) Harvard 155 cm telescope • Atpresentonlysingletargets (searchfornanosecimpulses) • Plannedall-skysurvey • Many „big” telescopesavailableall over theworldlookingfor a cutting-edge program inastronomy

10. radiotelescope something strange on the sky Changing symbols of the SETI Institute ?????????

11. SETI present: paradigm shift • „Exoplanets and extremophiles have been real game changers ... so there might be a lot more habitable real estate out there than we once thought.” • „We are now willing to re-question everything and think about what we can do now that was not considered possible when we got started.” Jill Tarter

12. Importantactors of the SETI fieldtoday SETI Institute, ATA • Breakthrough Listen, Berkeley, Meerkat Array • Optical observations • IAA SETI Committee • SETI League • Kepler, TESS and other space telescopes discovering and analysing data on exoplanets

13. Some recent possible SETI initiatives • LOFAR, Low Frequency Array • IR and gamma burst observations • Study of the atmosphere of extrasolar planets • Interstellar archeology: looking for technomarkers in nearby stellar systems, (Carrigan) • Millimetron – Russian and ESA space radiotelescope (VLBI)

14. Far future: Colossus and SKA A telescope of 74 m diameter (58 independent 8 m off-axis telescopes) for ping detection (distinctive transient events) SquareKilometer Array in Australia and Afrika

15. SETI: future possibilities (direct observation of habitable exoplanets)

16. Milan Ćirković: The Great Silence • Oxford University Press 2018 • The Science and Philosophy of Fermi’s Paradox

17. Solutions of Fermi’s ParadoxbasedonAxioms? Hypotheses? Assumptions? • Naturalism: „we should NOT invokesupernaturalagencies, and capacitiesinsearchingfor an explanation of observedphenomena” • Realism: „weachievebestresultsin most casesbyfollowingempiricalevidence and interpretingitinthe most direct and simplemanner”

18. It is expected, but is it true? • „Copernicanism” or „Principle of Mediocrity” or „Principle of Typicality”: Our Galaxy, our Sun and our planet are all typical both in their position in space and in time.

19. Non-exclusivity principle • „…diversity will tend to prevail unless there exist a mechanism to enforce conformity” (Brin, 1983) • E.g.: „classical hypothesis that all cosmic civilizations self-destruct upon developing nuclear or biological weapons … independently from a wide variety of local properties!”

20. SETI: future„It is verydifficulttopredictanything, thefutureinparticular”unknownsource

21. SETI observational programs • Study of „Big Data” collectedbyastronomicalsatellitesineverywavelength and everywhere; • SearchafterKardashev III typesupercivilizationsincosmologicaldistances; • Construction of a „shortlist” of allpromisingphenomenawithinthedatabase; • Maximum intensitycollectivestudy of thesephenomenabyexistingorplannedinstruments; • Launch of a specialspaceprobeintothefocalpoint of the Sun oppositetothe most promisingobject (proposedspacemissionbyClaudio Maccone).

22. Manyinformationcarriersmightexist Bosonastronomy: photon (radio,IR, optical, UV, X, gamma rays); graviton (gravitywaves) Particleastronomy: microscopicparticlesfermions (neutrinos, electrons and protons – cosmicrays) heavyparticles (atomicnuclei - cosmicrays); macroscopicparticlesorobjects (meteorites, dust, asteroids, comets). Directtechniques: spaceprobes, exploration, astroengineeringactivityintheSolar System

23. Looking for alien trash or space probes in the Solar Sytem • On the Moon: searching artifacts of extra-terrestrial origin on the surface (Paul Davies) • A search for objects near the Earth-Moon Lagrangian points ( FranciscoValdes and Robert Freitas) • Search after peculiar objects in the asteroid belts • a.s.o

24. SETI: theoretical studies, Fermi paradox • „We need a real, comprehensive astrobiologicaltheory in order to classify the explanatory hypotheses by their likelihood” • „Artificial intelligence and postbiological evolution are bound to play key roles in many of the explanatory hypotheses for Fermi’s paradox” • Cirkovic

25. Other SETI effortsneededinthefuture • Close cooperation between astrobiology and SETI particularly in the study of Earth-like exoplanets; • To establish an International Center for SETI in order to coordinate observational and theoretical works all over the Earth; • Concentrate international efforts to defend particularly suitable places for SETI observations and alien artefact collection (e.g. far-side of the Moon).

26. An audacious opinion • „Extraterrestrialcivilizitionshavenotyetbeenfound, becauseineffecttheyhavenotyetbeensearchedfor!” • Nikolai Kardashev 1932 - 2019

27. Thank you for your attention!