NATS 1880 Life Beyond Earth Class 1 PDF

NATS 1880 Life Beyond Earth Class 1: Universe of Life Image Credit: Night Café AI Image Generator Admin There will be iClicker questions in this class https://join.iclicker.com/GGUU There will also be polls designed to get you talking and thinking No...

NATS 1880 Life Beyond Earth Class 1: Universe of Life Image Credit: Night Café AI Image Generator Admin There will be iClicker questions in this class https://join.iclicker.com/GGUU There will also be polls designed to get you talking and thinking Not for marks, but use iClicker! Usually titled “What do you think?” or has a note 4 Learning Goals Describe the roles played by many science disciplines in the science of astrobiology Describe the characteristics of the search we are embarking upon Illustrate how our civilization might change following the discovery of an extra-terrestrial intelligence 6 Is there life beyond Earth? A philosopher might say…. “A single ear of wheat in a large field is as strange as a single world in infinite space.” - Metrodorus of Chios (4th Century B.C.) Prof. Webb | 8 A science fiction writer might say… “Sometimes I think we’re alone in the universe, and sometimes I think we’re not. In either case, the idea is quite staggering.” – Sir Arthur C. Clarke Credit – ITU Pictures Prof. Webb | 9 An astronomer might say…. “The exoplanets and extremophiles are pointing out that there is a lot more potentially habitable real estate out there than we ever imagined.” – Jill Tartar (SETI) Credit – SETI Institute Prof. Webb | 10 A York University student might say…. A) Absolutely! B) No idea, that is why I am taking this course C) No way! D) Sorry, I am in the wrong class * Not for marks Prof. Webb | 11 What are we searching for? What do we mean by ”life”? Simple, complex, or intelligent Earth-like or alien Life is difficult to define Reproduction? Movement and Growth? We can use Earth as a starting point! Wide range of life-forms, but just Credit – FutureLearn one planet Prof. Webb | 13 Is it reasonable to imagine life beyond Earth? 14 What do we think we know? No macroscopic life in the solar system Microbial life in the solar system possible Many potentially habitable worlds have been discovered beyond our solar system No detection of past or present habitability beyond Earth Capabilities are growing! Credit – freepik Prof. Webb | 15 AST 251 | U of T | Dr. Reid | 16 Starshot Breakthrough Starshot program aims to send nanocrafts to other star systems! Credit: Breakthrough Starshot Prof. Webb | 17 The Search for Life Beyond Earth Interdisciplinary Approach Astronomy Planetary Science Including geology and atmospheric science Biology Prof. Webb | 18 Credit – Princeton University Press Astronomy Earth is not special Universal Laws of Physics Nothing unique about our place in the Galaxy or the Universe 200 Billion, Trillion stars in the Universe At least as many planets (if not more) e.g. Kepler 11 has at least 6 known planets Credit – Princeton University Press Image is an artist’s conception Prof. Webb | 19 Planetary Science How do planets form? A natural by-product of star formation How and why do planets differ? Vast Rocky vs “Gas” planet numbers of stars should Atmosphere have habitable planets Geological Activity Composition Credit – Princeton University Press Prof. Webb | 20 Biology Universal Laws of Biology? Only have one reference point Earth Early Earth chemistry can lead to organic molecules Also seen in meteorites and clouds of Biology may be common in gas in interstellar space the Universe Transition from Chemistry to Biology not terribly difficult? Microscopic life exists over a wide range of conditions e.g. extremophiles Credit – Princeton University Press Prof. Webb | 21 Where should we search for life in the Universe? Anywhere with the “Ingredients” for Life A liquid or solvent (i.e. water) seems important Heat (i.e. Sun) Time Need to develop complex molecules Protection Harmful radiation for space (i.e. atmosphere) Our Own Solar System Planets, dwarf planets, moons, asteroids, comets Evidence for past surface waterflow on Mars Evidence for sub-surface water on Mars and several moons Europa, Ganymede, Callisto, Enceladus Thick atmosphere and methane lakes on Titan Protection and solvents Credit – Princeton University Press Alien life? Prof. Webb | 24 Beyond Our Solar System Statistically more likely Difficult due to distances to other stars Spacecraft travel time of 100,000 years to nearest stars Telescopes can find planets and measure basic properties Spectral analysis just now a reality Prof. Webb | 25 Credit – NASA Could aliens be searching for us? Direct Communication Search for Extraterrestrial Intelligence (SETI) Institute Search for alien signals from intelligent lifeforms Messaging to Extraterrestrial Intelligence Send signals to aliens Prof. Webb | 29 Credit – Princeton University Press  Should we be contacting extraterrestrials? Pursuit of the answer to the fundamental question - “Are we alone in the Universe?” Peace or War Humanity does not have the best track record A unified Earth? Knowledge exchange Medical, environmental, philosophical Weapons Prof. Webb | 32 Credit – Daniel Downey  How do we study the possibility of life beyond Earth? 34 Credit: NASA Collaborative and Interdisciplinary Science Studying the conditions conductive to the origin and ongoing existence of life Looking for such conditions on other planets in our solar system and around other stars Looking for the actual occurrence of life elsewhere Credit – NASA Bringing it all together and looking ahead…. To search for life, we must first define it! Armed with a definition, the search for life is interdisciplinary and difficult Astronomy, biology, planetary sciences Many places within the solar system have many (or all) of the ingredients we “think” are necessary for life Many places beyond the solar system “could” have the ingredients we think are necessary for life, but its hard to be sure Communicating with extraterrestrials a more direct way of finding intelligent life, but is it worth it? 36 Questions? Prof. Webb | 37 52