Jill Tarter PUBLIC LECTURE TRANSCRIPT
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SETI Is Part of Astrobiology
SETI is Part of Astrobiology Jason T. Wright Department of Astronomy & Physics Center for Exoplanets and Habitable Worlds Penn State University Phone: (814) 863-8470 [email protected] I. SETI is Part of Astrobiology “Traditional SETI is not part of astrobiology” declares the NASA Astrobiology Strategy 2015 document (p. 150). This is incorrect.1 Astrobiology is the study of life in the universe, in particular its “origin, evolution, distribution, and future in the universe.” [emphasis mine] Searches for biosignatures are searches for the results of interactions between life and its environment, and could be sensitive to even primitive life on other worlds. As such, these searches focus on the origin and evolution of life, using past life on Earth as a guide. But some of the most obvious ways in which Earth is inhabited today are its technosignatures such as radio transmissions, alterations of its atmosphere by industrial pollutants, and probes throughout the Solar System. It seems clear that the future of life on Earth includes the development of ever more obvious technosignatures. Indeed, the NASA Astrobiology Strategy 2015 document acknowledges “the possibility” that such technosignatures exist, but erroneously declares them to be “not part of contemporary SETI,” and mentions them only to declare that we should “be aware of the possibility” and to “be sure to include [technosignatures] as a possible kind of interpretation we should consider as we begin to get data on the exoplanets.” In other words, while speculation on the nature of biosignatures and the design of multi-billion dollar missions to find those signatures is consistent with NASA’s vision for astrobiology, speculation on the nature of technosignatures and the design of observations to find them is not. -
Lecture-29 (PDF)
Life in the Universe Orin Harris and Greg Anderson Department of Physics & Astronomy Northeastern Illinois University Spring 2021 c 2012-2021 G. Anderson., O. Harris Universe: Past, Present & Future – slide 1 / 95 Overview Dating Rocks Life on Earth How Did Life Arise? Life in the Solar System Life Around Other Stars Interstellar Travel SETI Review c 2012-2021 G. Anderson., O. Harris Universe: Past, Present & Future – slide 2 / 95 Dating Rocks Zircon Dating Sedimentary Grand Canyon Life on Earth How Did Life Arise? Life in the Solar System Life Around Dating Rocks Other Stars Interstellar Travel SETI Review c 2012-2021 G. Anderson., O. Harris Universe: Past, Present & Future – slide 3 / 95 Zircon Dating Zircon, (ZrSiO4), minerals incorporate trace amounts of uranium but reject lead. Naturally occuring uranium: • U-238: 99.27% • U-235: 0.72% Decay chains: • 238U −→ 206Pb, τ =4.47 Gyrs. • 235U −→ 207Pb, τ = 704 Myrs. 1956, Clair Camron Patterson dated the Canyon Diablo meteorite: τ =4.55 Gyrs. c 2012-2021 G. Anderson., O. Harris Universe: Past, Present & Future – slide 4 / 95 Dating Sedimentary Rocks • Relative ages: Deeper layers were deposited earlier • Absolute ages: Decay of radioactive isotopes old (deposited last) oldest (depositedolder first) c 2012-2021 G. Anderson., O. Harris Universe: Past, Present & Future – slide 5 / 95 Grand Canyon: Earth History from 200 million - 2 billion yrs ago. Dating Rocks Life on Earth Earth History Timeline Late Heavy Bombardment Hadean Shark Bay Stromatolites Cyanobacteria Q: Earliest Fossils? Life on Earth O2 History Q: Life on Earth How Did Life Arise? Life in the Solar System Life Around Other Stars Interstellar Travel SETI Review c 2012-2021 G. -
The Mystery of Methane on Mars and Titan
The Mystery of Methane on Mars & Titan By Sushil K. Atreya MARS has long been thought of as a possible abode of life. The discovery of methane in its atmosphere has rekindled those visions. The visible face of Mars looks nearly static, apart from a few wispy clouds (white). But the methane hints at a beehive of biological or geochemical activity underground. Of all the planets in the solar system other than Earth, own way, revealing either that we are not alone in the universe Mars has arguably the greatest potential for life, either extinct or that both Mars and Titan harbor large underground bodies or extant. It resembles Earth in so many ways: its formation of water together with unexpected levels of geochemical activ- process, its early climate history, its reservoirs of water, its vol- ity. Understanding the origin and fate of methane on these bod- canoes and other geologic processes. Microorganisms would fit ies will provide crucial clues to the processes that shape the right in. Another planetary body, Saturn’s largest moon Titan, formation, evolution and habitability of terrestrial worlds in also routinely comes up in discussions of extraterrestrial biology. this solar system and possibly in others. In its primordial past, Titan possessed conditions conducive to Methane (CH4) is abundant on the giant planets—Jupiter, the formation of molecular precursors of life, and some scientists Saturn, Uranus and Neptune—where it was the product of chem- believe it may have been alive then and might even be alive now. ical processing of primordial solar nebula material. On Earth, To add intrigue to these possibilities, astronomers studying though, methane is special. -
Optical SETI: the All-Sky Survey
Professor van der Veen Project Scientist, UCSB Department of Physics, Experimental Cosmology Group class 4 [email protected] frequencies/wavelengths that get through the atmosphere The Planetary Society http://www.planetary.org/blogs/jason-davis/2017/20171025-seti-anybody-out-there.html THE ATMOSPHERE'S EFFECT ON ELECTROMAGNETIC RADIATION Earth's atmosphere prevents large chunks of the electromagnetic spectrum from reaching the ground, providing a natural limit on where ground-based observatories can search for SETI signals. Searching for technology that we have, or are close to having: Continuous radio searches Pulsed radio searches Targeted radio searches All-sky surveys Optical: Continuous laser and near IR searches Pulsed laser searches a hypothetical laser beacon watch now: https://www.youtube.com/watch?time_continue=41&v=zuvyhxORhkI Theoretical physicist Freeman Dyson’s “First Law of SETI Investigations:” Every search for alien civilizations should be planned to give interesting results even when no aliens are discovered. Interview with Carl Sagan from 1978: Start at 6:16 https://www.youtube.com/watch?v=g- Q8aZoWqF0&feature=youtu.be Anomalous signal recorded by Big Ear Telescope at Ohio State University. Big Ear was a flat, aluminum dish three football fields wide, with reflectors at both ends. Signal was at 1,420 MHz, the hydrogen 21 cm ‘spin flip’ line. http://www.bigear.org/Wow30th/wow30th.htm May 15, 2015 A Russian observatory reports a strong signal from a Sun-like star. Possibly from advanced alien civilization. The RATAN-600 radio telescope in Zelenchukskaya, at the northern foot of the Caucasus Mountains location: star HD 164595 G-type star (like our Sun) 94.35 ly away, visually located in constellation Hercules 1 planet that orbits it every 40 days unusual radio signal detected – 11 GHz (2.7 cm) claim: Signal from a Type II Kardashev civilization Only one observation Not confirmed by other telescopes Russian Academy of Sciences later retracted the claim that it was an ETI signal, stating the signal came from a military satellite. -
SETI SETI Stands for Search for Extraterrestrial Intelligence, and Usually Is Meant As an Acronym for Searches for Radio Commu
SETI SETI stands for Search for Extraterrestrial Intelligence, and usually is meant as an acronym for searches for radio commu- nications from extraterrestrials which has been its backbone. It began with a seminal paper in 1959 by Giuseppe Cocconi and Philip Morrison in Nature suggesting that the best way to find extraterrestrial civilizations was to search in the radio near 1420 MHz (H spin-flip). The first SETI, project Ozma (1960, Frank Drake, originator of the Drake equation) used the 85- foot Green Bank, WV telescope; today SETI@home uses the 1000-foot Arecibo radio telescope in Puerto Rico. The Plane- tary Society has played an important role in supporting SETI, ever since the ban on Federal funding for it in 1982-83 and from 1992 to the present. Other projects have included Suit- case SETI, META, BETA, SERENDIP and META II. Thinking about SETI took a new turn in 1967 when Joce- lyn Bell and her advisor, Anthony Hewish, discovered pulsars, which they initially referred to, jokingly, as LGM (little green men). Another pioneer of SETI was Bernard Oliver, Vice Pres- ident of Hewlett Packard, who suggested in 1971 the cosmic waterhole hypothesis and emphasized the relative \quietness" of the radio spectrum between 1 and 1000 GHz. Project Ozma operated for about 3 months, devoting about 200 hours of observation to its two targets Tau Ceti and Epsilon Eridani. It scanned 7200 channels each with a bandwidth of 100 Hz, centered on 1420 MHz. By looking at adjacent frequencies, Doppler shifts caused by relative motions of our planets and Suns would be incorporated. -
Astrobiology and the Search for Life Beyond Earth in the Next Decade
Astrobiology and the Search for Life Beyond Earth in the Next Decade Statement of Dr. Andrew Siemion Berkeley SETI Research Center, University of California, Berkeley ASTRON − Netherlands Institute for Radio Astronomy, Dwingeloo, Netherlands Radboud University, Nijmegen, Netherlands to the Committee on Science, Space and Technology United States House of Representatives 114th United States Congress September 29, 2015 Chairman Smith, Ranking Member Johnson and Members of the Committee, thank you for the opportunity to testify today. Overview Nearly 14 billion years ago, our universe was born from a swirling quantum soup, in a spectacular and dynamic event known as the \big bang." After several hundred million years, the first stars lit up the cosmos, and many hundreds of millions of years later, the remnants of countless stellar explosions coalesced into the first planetary systems. Somehow, through a process still not understood, the laws of physics guiding the unfolding of our universe gave rise to self-replicating organisms − life. Yet more perplexing, this life eventually evolved a capacity to know its universe, to study it, and to question its own existence. Did this happen many times? If it did, how? If it didn't, why? SETI (Search for ExtraTerrestrial Intelligence) experiments seek to determine the dis- tribution of advanced life in the universe through detecting the presence of technology, usually by searching for electromagnetic emission from communication technology, but also by searching for evidence of large scale energy usage or interstellar propulsion. Technology is thus used as a proxy for intelligence − if an advanced technology exists, so to does the ad- vanced life that created it. -
The Radio Search for Technosignatures in the Decade 2020–2030
Astro2020 Science White Paper The radio search for technosignatures in the decade 2020–2030 Background photo: central region of the Galaxy by Yuri Beletsky, Carnegie Las Campanas Observatory Thematic Area: Planetary Systems Principal Author: Name: Jean-Luc Margot Institution: University of California, Los Angeles Email: [email protected] Phone: 310.206.8345 Co-authors: Steve Croft (University of California, Berkeley), T. Joseph W. Lazio (Jet Propulsion Laboratory), Jill Tarter (SETI Institute), Eric J. Korpela (University of California, Berkeley) March 11, 2019 1 Scientific context Are we alone in the universe? This question is one of the most profound scientific questions of our time. All life on Earth is related to a common ancestor, and the discovery of other forms of life will revolutionize our understanding of living systems. On a more philosophical level, it will transform our perception of humanity’s place in the cosmos. Observations with the NASA Kepler telescope have shown that there are billions of habitable worlds in our Galaxy [e.g., Borucki, 2016]. The profusion of planets, coupled with the abundance of life’s building blocks in the universe, suggests that life itself may be abundant. Currently, the two primary strategies for the search for life in the universe are (1) searching for biosignatures in the Solar System or around nearby stars and (2) searching for technosignatures emitted from sources in the Galaxy and beyond [e.g., National Academies of Sciences, Engineer- ing, and Medicine, 2018]. Given our present knowledge of astrobiology, there is no compelling reason to believe that one strategy is more likely to succeed than the other. -
CASKAR: a CASPER Concept for the SKA Phase 1 Signal Processing Sub-System
CASKAR: A CASPER concept for the SKA phase 1 Signal Processing Sub-system Francois Kapp, SKA SA Outline • Background • Technical – Architecture – Power • Cost • Schedule • Challenges/Risks • Conclusions Background CASPER Technology MeerKAT Who is CASPER? • Berkeley Wireless Research Center • Nancay Observatory • UC Berkeley Radio Astronomy Lab • Oxford University Astrophysics • UC Berkeley Space Sciences Lab • Metsähovi Radio Observatory, Helsinki University of • Karoo Array Telescope / SKA - SA Technology • NRAO - Green Bank • New Jersey Institute of Technology • NRAO - Socorro • West Virginia University Department of Physics • Allen Telescope Array • University of Iowa Department of Astronomy and • MIT Haystack Observatory Physics • Harvard-Smithsonian Center for Astrophysics • Ohio State University Electroscience Lab • Caltech • Hong Kong University Department of Electrical and Electronic Engineering • Cornell University • Hartebeesthoek Radio Astronomy Observatory • NAIC - Arecibo Observatory • INAF - Istituto di Radioastronomia, Northern Cross • UC Berkeley - Leuschner Observatory Radiotelescope • Giant Metrewave Radio Telescope • University of Manchester, Jodrell Bank Centre for • Institute of Astronomy and Astrophysics, Academia Sinica Astrophysics • National Astronomical Observatories, Chinese Academy of • Submillimeter Array Sciences • NRAO - Tucson / University of Arizona Department of • CSIRO - Australia Telescope National Facility Astronomy • Parkes Observatory • Center for Astrophysics and Supercomputing, Swinburne University -
Biosignatures Search in Habitable Planets
galaxies Review Biosignatures Search in Habitable Planets Riccardo Claudi 1,* and Eleonora Alei 1,2 1 INAF-Astronomical Observatory of Padova, Vicolo Osservatorio, 5, 35122 Padova, Italy 2 Physics and Astronomy Department, Padova University, 35131 Padova, Italy * Correspondence: [email protected] Received: 2 August 2019; Accepted: 25 September 2019; Published: 29 September 2019 Abstract: The search for life has had a new enthusiastic restart in the last two decades thanks to the large number of new worlds discovered. The about 4100 exoplanets found so far, show a large diversity of planets, from hot giants to rocky planets orbiting small and cold stars. Most of them are very different from those of the Solar System and one of the striking case is that of the super-Earths, rocky planets with masses ranging between 1 and 10 M⊕ with dimensions up to twice those of Earth. In the right environment, these planets could be the cradle of alien life that could modify the chemical composition of their atmospheres. So, the search for life signatures requires as the first step the knowledge of planet atmospheres, the main objective of future exoplanetary space explorations. Indeed, the quest for the determination of the chemical composition of those planetary atmospheres rises also more general interest than that given by the mere directory of the atmospheric compounds. It opens out to the more general speculation on what such detection might tell us about the presence of life on those planets. As, for now, we have only one example of life in the universe, we are bound to study terrestrial organisms to assess possibilities of life on other planets and guide our search for possible extinct or extant life on other planetary bodies. -
Russell Tracy Crawford Papers MS.265
http://oac.cdlib.org/findaid/ark:/13030/c8sf31rj No online items Guide to the Russell Tracy Crawford papers MS.265 Maureen Carey and Alix Norton University of California, Santa Cruz 2016 1156 High Street Santa Cruz 95064 [email protected] URL: http://guides.library.ucsc.edu/speccoll Guide to the Russell Tracy MS.265 1 Crawford papers MS.265 Language of Material: English Contributing Institution: University of California, Santa Cruz Title: Russell Tracy Crawford papers creator: Crawford, R. T. (Russell Tracy), 1876- Identifier/Call Number: MS.265 Physical Description: 2.45 Linear Feet3 boxes, 1 oversize box Date (inclusive): 1897-1960 Access Collection is open for research. Arrangement This collection is organized into five series: 1. Biographical 2. Correspondence 3. Notes and notebooks 4. Observations and charts 5. Writings Materials within each series are arranged in chronological order. Biographical / Historical Russell Tracy Crawford was an astronomer and professor who was associated with the University of California for over 50 years. Earning his degrees in astronomy in 1897 and 1901, he then worked as a professor and astronomer for the university in various capacities until his retirement in 1946. Crawford earned one of the first fellowships granted by the Lick Observatory in 1897, and finished his doctoral work there using the meridian circle with astronomer R.H. Tucker. Crawford is well known for his work in theoretical astronomy, and his observations and computations of comet orbits. He published over a hundred articles and a book entitled The Determination of Orbits of Comets and Asteroids. Crawford was born on March 26, 1876, in Davis, California. -
Monday, November 13, 2017 WHAT DOES IT MEAN to BE HABITABLE? 8:15 A.M. MHRGC Salons ABCD 8:15 A.M. Jang-Condell H. * Welcome C
Monday, November 13, 2017 WHAT DOES IT MEAN TO BE HABITABLE? 8:15 a.m. MHRGC Salons ABCD 8:15 a.m. Jang-Condell H. * Welcome Chair: Stephen Kane 8:30 a.m. Forget F. * Turbet M. Selsis F. Leconte J. Definition and Characterization of the Habitable Zone [#4057] We review the concept of habitable zone (HZ), why it is useful, and how to characterize it. The HZ could be nicknamed the “Hunting Zone” because its primary objective is now to help astronomers plan observations. This has interesting consequences. 9:00 a.m. Rushby A. J. Johnson M. Mills B. J. W. Watson A. J. Claire M. W. Long Term Planetary Habitability and the Carbonate-Silicate Cycle [#4026] We develop a coupled carbonate-silicate and stellar evolution model to investigate the effect of planet size on the operation of the long-term carbon cycle, and determine that larger planets are generally warmer for a given incident flux. 9:20 a.m. Dong C. F. * Huang Z. G. Jin M. Lingam M. Ma Y. J. Toth G. van der Holst B. Airapetian V. Cohen O. Gombosi T. Are “Habitable” Exoplanets Really Habitable? A Perspective from Atmospheric Loss [#4021] We will discuss the impact of exoplanetary space weather on the climate and habitability, which offers fresh insights concerning the habitability of exoplanets, especially those orbiting M-dwarfs, such as Proxima b and the TRAPPIST-1 system. 9:40 a.m. Fisher T. M. * Walker S. I. Desch S. J. Hartnett H. E. Glaser S. Limitations of Primary Productivity on “Aqua Planets:” Implications for Detectability [#4109] While ocean-covered planets have been considered a strong candidate for the search for life, the lack of surface weathering may lead to phosphorus scarcity and low primary productivity, making aqua planet biospheres difficult to detect. -
Astrobiology for a General Reader
Astrobiology for a General Reader Astrobiology for a General Reader: A Questions and Answers Approach By Vera M. Kolb and Benton C. Clark III Astrobiology for a General Reader: A Questions and Answers Approach By Vera M. Kolb and Benton C. Clark III This book first published 2020 Cambridge Scholars Publishing Lady Stephenson Library, Newcastle upon Tyne, NE6 2PA, UK British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Copyright © 2020 by Vera M. Kolb and Benton C. Clark III All rights for this book reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owner. ISBN (10): 1-5275-5502-X ISBN (13): 978-1-5275-5502-0 V. M. K. dedicates this book to the memory of her dear brother, Vladimir Kolb. B. C. C. dedicates this book to the memory of his beloved wife, Johanna. TABLE OF CONTENTS Preface ....................................................................................................... ix Acknowledgments ..................................................................................... xi Chapter 1 .................................................................................................... 1 What is astrobiology? Chapter 2 .................................................................................................... 5 Understanding the concept of life within the astrobiology framework: