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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. -
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. -
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. -
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 -
Astrobiology: the Origin, Evolu'on, Distribu'on, and Future of Life in The
Astrobiology: the origin, evolu3on, distribu3on, and future of life in the universe Outline of this class: Life, extreme life on earth Where else in solar system could life exist? Mars, Titan& Europa, Habitable zone (review), difficulty with es3mang probability of life, Drake equaon for es3mang likelihood SETI: Search for Extraterrestrial Intelligence Reminder: • No class this Wednesday, Happy Thanksgiving! • Next Monday: primarily review • Next Wed: YOU each do class presentaon (30 % of your final) • Mon, Dec 9 Final exam. Would you all like to follow this with a potluck supper? (ColeSe and I will contribute major items!) No need to cook something! What defines life? • the capacity to grow, • metabolize (convert food to energy) • respond (to s3muli), • adapt • reproduce What is necessary? Recent discoveries of life under extreme condi3ons on earth (extremophiles) show that neither sunlight nor oxygen are required yellowstone Yellowstone Naonal Park: microbes live in boiling water (90 C). Other pools are extremely acidic, yet microbes and bacteria thrive there Life in extreme condi3ons on earth Black smoker, deep in the ocean: an example of life that has no need of sunlight: From vents deep in the ocean hydrogen sulfide provide energy for bacteria, which in turn feed clams, tube worms (up to 10 ` long) Bacteria up to a mile underground: water seeps in, and bacteria generates energy from chemical reac3ons A NASA favorite: Tardigrade (water bear) that survive at temps from absolute zero to above boiling, pressures up to 6x that of deepest ocean trenches, ionizing radiaon. They can go without food or water for more than 10 years and then revive. -
A Study of Giant Radio Galaxies at Ratan-600 173
Bull. Spec. Astrophys. Obs., 2011, 66, 171–182 c Special Astrophysical Observatory of the Russian AS, 2018 A Study of Giant Radio Galaxies at RATAN-600 M.L. Khabibullinaa, O.V. Verkhodanova, M. Singhb, A. Piryab, S. Nandib, N.V. Verkhodanovaa a Special Astrophysical Observatory of the Russian AS, Nizhnij Arkhyz 369167, Russia; b Aryabhatta Research Institute of Observational Sciences, Manora Park, Nainital 263 129, India Received July 28, 2010; accepted September 15, 2010. We report the results of flux density measurements in the extended components of thirteen giant radio galaxies, made with the RATAN-600 in the centimeter range. Supplementing them with the WENSS, NVSS and GB6 survey data we constructed the spectra of the studied galaxy components. We computed the spectral indices in the studied frequency range and demonstrate the need for a detailed account of the integral contribution of such objects into the background radiation. Key words: Radio lines: galaxies—techniques: radar astronomy 1. INTRODUCTION than the one, expected from the evolutional models. As noted in [8], such radio galaxies may affect the According to the generally accepted definition, gi- processes of galaxy formation, since the pressure of ant radio galaxies (GRGs) are the radio sources with gas, outflowing from the radio source, may compress linear sizes greater than 1 Mpc, i.e. the largest ra- the cold gas clouds thus initiating the development dio sources in the Universe. They mostly belong to of stars on the one hand, and stop the formation of the morphological type FR II [1] and are identified galaxies on the other hand. -
Essential Radio Astronomy
February 2, 2016 Time: 09:25am chapter1.tex © Copyright, Princeton University Press. No part of this book may be distributed, posted, or reproduced in any form by digital or mechanical means without prior written permission of the publisher. 1 Introduction 1.1 AN INTRODUCTION TO RADIO ASTRONOMY 1.1.1 What Is Radio Astronomy? Radio astronomy is the study of natural radio emission from celestial sources. The range of radio frequencies or wavelengths is loosely defined by atmospheric opacity and by quantum noise in coherent amplifiers. Together they place the boundary be- tween radio and far-infrared astronomy at frequency ν ∼ 1 THz (1 THz ≡ 1012 Hz) or wavelength λ = c/ν ∼ 0.3 mm, where c ≈ 3 × 1010 cm s−1 is the vacuum speed of light. The Earth’s ionosphere sets a low-frequency limit to ground-based radio astronomy by reflecting extraterrestrial radio waves with frequencies below ν ∼ 10 MHz (λ ∼ 30 m), and the ionized interstellar medium of our own Galaxy absorbs extragalactic radio signals below ν ∼ 2 MHz. The radio band is very broad logarithmically: it spans the five decades between 10 MHz and 1 THz at the low-frequency end of the electromagnetic spectrum. Nearly everything emits radio waves at some level, via a wide variety of emission mechanisms. Few astronomical radio sources are obscured because radio waves can penetrate interstellar dust clouds and Compton-thick layers of neutral gas. Because only optical and radio observations can be made from the ground, pioneering radio astronomers had the first opportunity to explore a “parallel universe” containing unexpected new objects such as radio galaxies, quasars, and pulsars, plus very cold sources such as interstellar molecular clouds and the cosmic microwave background radiation from the big bang itself. -
The Jansky Very Large Array
The Jansky Very Large Array To ny B e a s l e y National Radio Astronomy Observatory Atacama Large Millimeter/submillimeter Array Expanded Very Large Array Robert C. Byrd Green Bank Telescope Very Long Baseline Array EVLA EVLA Project Overview • The EVLA Project is a major upgrade of the Very Large Array. Upgraded array JanskyVLA • The fundamental goal is to improve all the observational capabilities of the VLA (except spatial resolution) by at least an order of magnitude • The project will be completed by early 2013, on budget and schedule. • Key aspect: This is a leveraged project – building upon existing infrastructure of the VLA. Key EVLA Project Goals EVLA • Full frequency coverage from 1 to 50 GHz. – Provided by 8 frequency bands with cryogenic receivers. • Up to 8 GHz instantaneous bandwidth – All digital design to maximize instrumental stability and repeatability. • New correlator with 8 GHz/polarization capability – Designed, funded, and constructed by HIA/DRAO – Unprecedented flexibility in matching resources to attain science goals. • <3 Jy/beam (1-, 1-Hr) continuum sensitivity at most bands. • <1 mJy/beam (1-, 1-Hr, 1-km/sec) line sensitivity at most bands. • Noise-limited, full-field imaging in all Stokes parameters for most observational fields. Jansky VLA-VLA Comparison EVLA Parameter VLA EVLA Factor Current Point Source Cont. Sensitivity (1,12hr.) 10 Jy 1 Jy 10 2 Jy Maximum BW in each polarization 0.1 GHz 8 GHz 80 2 GHz # of frequency channels at max. BW 16 16,384 1024 4096 Maximum number of freq. channels 512 4,194,304 8192 12,288 Coarsest frequency resolution 50 MHz 2 MHz 25 2 MHz Finest frequency resolution 381 Hz 0.12 Hz 3180 .12 Hz # of full-polarization spectral windows 2 64 32 16 (Log) Frequency Coverage (1 – 50 GHz) 22% 100% 5 100% EVLA Project Status EVLA • Installation of new wideband receivers now complete at: – 4 – 8 GHz (C-Band) – 18 – 27 GHz (K-Band) – 27 – 40 GHz (Ka-Band) – 40 – 50 GHz (Q-Band) • Installation of remaining four bands completed late-2012: – 1 – 2 GHz (L-Band) 19 now, completed end of 2012. -
Gigantic Galaxies Discovered with the Meerkat Telescope
18 January 2021 Gigantic galaxies discovered with the MeerKAT telescope The two giant radio galaxies found with the MeerKAT telescope. In the background is the sky as seen in optical light. Overlaid in red is the radio light from the enormous radio galaxies, as seen by MeerKAT. Left: MGTC J095959.63+024608.6. Right: MGTC J100016.84+015133.0. Image: I. Heywood (Oxford/Rhodes/SARAO) Two giant radio galaxies have been discovered with South Africa's powerful MeerKAT telescope. These galaxies are amongst the largest single objects in the universe and are thought to be quite rare. The discovery has been published online in the Monthly Notices of the Royal Astronomical Society. The detection of two of these monsters by MeerKat, in a relatively small patch of sky suggests that these scarce giant radio galaxies may actually be much more common than previously thought. This gives astronomers vital clues about how galaxies have changed and evolved throughout cosmic history. Many galaxies have supermassive black holes residing in their midst. When large amounts of interstellar gas start to orbit and fall in towards the black hole, the black hole becomes 'active' and huge amounts of energy are released from this region of the galaxy. In some active galaxies, charged particles interact with the strong magnetic fields near the black hole and release huge beams, or 'jets' of radio light. The radio jets of these so-called 'radio galaxies' can be many times larger than the galaxy itself and can extend vast distances into intergalactic space. Dr Jacinta Delhaize, a Research Fellow at the University of Cape Town (UCT) and lead author of the work, said: "Many hundreds of thousands of radio galaxies have already been discovered. -
Data Fusion from Diverse Resources for Optical Identification Of
Astronomical Data Analysis Software and Systems XIII ASP Conference Series, Vol. 314, 2004 F. Ochsenbein, M. Allen, and D. Egret, eds. Data Fusion from Diverse Resources for Optical Identification of Radio Sources. O. P. Zhelenkova and V. V. Vitkovskij Informatics Department, Special Astrophysical Observatory of RAS Nizhnij Arkhyz, Russia, Email: [email protected] Abstract. Optical identification of the SS sample of the RC radio source catalogue was impossible without the use of additional astronom- ical resources. The volume of information for each source grew from the 100 bytes for each RC-catalogue row up to 10MB including radio and optical observations, information from catalogues and surveys, data pro- cessing results and files for Internet publication. Such work pushes us to find a solution for integration of heterogeneous data and realization of the discovery procedure. The experience gained in this project has allowed formalization of a procedure for distant radio galaxy discovery in the subject mediator context. 1. Introduction The BIG TRIO (Goss et al. 1992, 1994) project to investigate distant radio galaxies was carried out at the Special Astrophysical Observatory of RAS. The list of objects for research consisted of radio sources from the deep survey of the sky strip observed with RATAN-600 (Parijskij et al. 1991, 1992). 104 radio galaxies were selected from the 1145 objects in the RC catalogue. The candidates were selected by radio source parameters including steep spectra and FRII morphology (Parijskij et al. 1996). Most of the RC catalogue radio sources have flux densities between 5 and 50 mJy. 10% of sources have a steep spectrum (α ≥ 0.9) and 70% have double radio structure. -
High Resolution Radio Astronomy Using Very Long Baseline Interferometry
IOP PUBLISHING REPORTS ON PROGRESS IN PHYSICS Rep. Prog. Phys. 71 (2008) 066901 (32pp) doi:10.1088/0034-4885/71/6/066901 High resolution radio astronomy using very long baseline interferometry Enno Middelberg1 and Uwe Bach2 1 Astronomisches Institut, Universitat¨ Bochum, 44801 Bochum, Germany 2 Max-Planck-Institut fur¨ Radioastronomie, Auf dem Hugel¨ 69, 53121 Bonn, Germany E-mail: [email protected] and [email protected] Received 3 December 2007, in final form 11 March 2008 Published 2 May 2008 Online at stacks.iop.org/RoPP/71/066901 Abstract Very long baseline interferometry, or VLBI, is the observing technique yielding the highest-resolution images today. Whilst a traditionally large fraction of VLBI observations is concentrating on active galactic nuclei, the number of observations concerned with other astronomical objects such as stars and masers, and with astrometric applications, is significant. In the last decade, much progress has been made in all of these fields. We give a brief introduction to the technique of radio interferometry, focusing on the particularities of VLBI observations, and review recent results which would not have been possible without VLBI observations. This article was invited by Professor J Silk. Contents 1. Introduction 1 2.9. The future of VLBI: eVLBI, VLBI in space and 2. The theory of interferometry and aperture the SKA 10 synthesis 2 2.10. VLBI arrays around the world and their 2.1. Fundamentals 2 capabilities 10 2.2. Sources of error in VLBI observations 7 3. Astrophysical applications 11 2.3. The problem of phase calibration: 3.1. Active galactic nuclei and their jets 12 self-calibration 7 2.4.