Astronomy 102/104: Our Solar System Prof. Jean-Luc Margot & Prof. Steve Squyres Lecture #1: Introduction & Outline Course Goals--why take Astro 102/104? Our philosophy, and a promise. Rules of the Road: Logistics Expectations Responsibilities Communication Detailed Syllabus. Astro 102/104 2 Purpose of Astro 102/104 To learn about our origins and our connection to the universe. To develop an appreciation for Earth as a fragile planetary body in a vast cosmos. To understand key principles and processes that govern the natural world. What is the solar system like today? Why? How did it get that way? To become familiar with the scientific process. To acquire tools for further inquiry and learning. Astro 102/104 3 Perfect timing This is a "Golden Age" of exploration! Spacecraft are exploring the planets now! MESSENGER ( 04-now): Mercury. Magellan ( 90-94): Venus. Mars Pathfinder ( 97) 97), MGS ( 97 97-06) 06), Mars Odyssey ( 02-now), MER ( 04-now), MRO ( 06-now): Mars. NEAR ( 97-01), Hayabusa ( 05): asteroids. Deep Impact ( 05), Stardust ( 04-06): comets. Galileo ( 95-03): Jupiter, satellites. Cassini/Huygens ( 04-now): Saturn, satellites. Voyager ( 80s): Jupiter, Saturn, Uranus, Neptune. AND MORE PAST, PRESENT, AND FUTURE! Astro 102/104 4 1
First flyby of Mercury in 30+ years reveals astonishing landforms! Lakes and rivers of methane on Titan! Astro 102/104 5 Astro 102/104 6 Astonishing worlds: Iapetus & Hyperion Astro 102/104 7 New Discoveries Being Made! Observations of asteroids: Many are highly porous. WHY? Some have satellites! HOW? Satellites of Jupiter and Saturn: Europa may have an ocean! Titan has hydrocarbon rain and rivers! Many objects discovered beyond Neptune. Hundreds of trans-neptunian objects. Pluto demoted! Can they do that? Many Sun-like stars have planets! Astro 102/104 8 2
Methods Discover and Explain important patterns and trends in the data. GOAL is to UNDERSTAND these patterns, NOT memorization of facts or numbers. Will concentrate on patterns and processes, but some knowledge of facts will be needed. Astro 102/104 9 Will there be math? At a lower level than what s in the get rich book. some geometry some algebra smidgen of trigonometry no calculus no logarithms no differential equations Astro 102/104 10 Some Obvious Patterns Inner Planets differ from Outer Planets. WHY? Astro 102/104 11 Some Striking Differences Example: Our Moon vs. Jupiter s moon Io. Rocky worlds, about the same size. Io: Volcanic. Covered with orange sulfur. Moon: Geologically dead. Covered with gray rock. WHY? Astro 102/104 12 3
Many Obvious Questions Why do outer planets have rings? What are rings, anyway? Are they permanent or temporary? Timescales How and when did the solar system form? (Answer: ~4,600,000,000 years ago!) How do we know that?? Astro 102/104 13 Astro 102/104 14 How Has the Solar System Evolved? Everything changes (Why? How? How Fast?) Examples: 4 billion years ago the Earth's atmosphere was very different than it is today (little or no oxygen). 4 billion years ago there may have been rivers or lakes on Mars (today it is a cold, bone dry desert). Mars has 2 moons today, but in 1 billion years it will have only 1 moon. Astro 102/104 15 Why Understand the Past? Extrapolation in time predictions about the future. How will Earth's atmosphere change? How will our climate change? Will objects strike the Earth? When? Extrapolation in space inferences about other places. Many other stars have planets. Could some of them be Earthlike? Could there be life?? Astro 102/104 16 4
Major Course Topics (1) General Solar System Concepts. (2) The Inner Solar System. (3) Small Bodies and the Outer Solar System. (4) Origins. Astro 102/104 17 Some Philosophy Our goal is to help you learn how to distinguish solid science from nonsense. For example: Planets around other stars. Repeated massive mass extinctions due to impacts. Evidence of ancient life on Mars. Ice at the poles of the Moon and Mercury. Which of these are TRUE, POSSIBLY TRUE, EXAGGERATIONS, OR EVEN NONSENSE? Use Carl Sagan s baloney detection kit. Astro 102/104 18 A Promise from us... We will work hard to help you learn. Our Responsibilities: Clearly present the information. Provide opportunities for questions, discussion. Be prepared for lectures, sections, labs. Provide fair and consistent grading. Make astronomy matter! Astro 102/104 19 And from you... But you must work hard too! Come to Lecture: Be here on time: prompt 11:15 start. Class will end at 12:05 (not 12:00 ) Go to Section. Do the reading. Turn in assignments on time. Ask Questions! Absolute academic integrity expected at all times. Astro 102/104 20 5
Lecture Style Follows the textbook, but not verbatim. More information provided only in lecture. Other lecture features: "The Main Point" "highlighted hli h dfor each class. Active learning. Group activities. Demonstrations. Discussions: Astronomy in the News, etc. Mars rover mission updates. Astro 102/104 21 Handouts: Syllabus and Ground Rules Astro 102/104 23 Your Weekly Section Meeting Your chance for more personal contact. Weekly quizzes or problem sets assigned. Detailed discussion of reading, lectures. Detailed discussion of homework. Critical preparation for prelims & final. You will get a better grade if you attend lectures and sections. Astro 102/104 24 Lab: Astro 104 Astro 104 has an additional lab component. Four classroom lab activities (in Clark 132): Radioactive Dating. Planetary Orbits. Impact Cratering. Rotation of Saturn and its Rings. One on-campus observatory activity (at Fuertes Observatory, weather permitting). Astro 102/104 25 6
Observing the Sky On clear Friday evenings, the Cornell Astronomical Society holds open-house observing at Fuertes Observatory on north campus, from 8:00 pm to midnight. Check http://astro.cornell.edu/facilities/fuertes You are strongly encouraged to go out and see the planets with your own eyes! Dress warmly. Planetarium program (SkyGazer) comes with your textbook. Astro 102/104 26 Additional Resources Course website: http://www.astro.cornell.edu/courses/a102 Lecture notes, homeworks, links, etc. Textbook publisher website: http://www.masteringastronomy.com Animated figures, tutorials, quizzes, etc. Numerous planetary data archives: Header graphic based on images from http://www.solarviews.com Calvin J. Hamilton Astro 102/104 27 For Additional Help Office Hours: Prof. Margot: MF 3:00-4:30 (but call ahead). Prof. Squyres by appointment only (due to continuing i Mars rover operations). Each TA has his/her own office hours: Consult the handout or web site for details. Any of us are available at other times by appointment, with advance notice. Next Lecture... The Sky. Historical Overview of Planetary Science. Reading this week: Preface and Chapter 1. Chapter 2.1, 2.4. Chapters 3, 4. Astro 102/104 28 Astro 102/104 29 7