To Scale Model of the James Webb Space Telescope (JWST)JWST (6.5 m) vs. HST (2.4 m)Course AnnouncementsAssignmentsSpace-Based AstronomySpace-Based Astronomy - IRSpace-Based Astronomy - IRSpace-Based Astronomy - IRSpace-Based Astronomy - MicrowavesSpace-Based Astronomy - MicrowavesThe Microwave GalaxyUltraviolet AstronomyUltraviolet AstronomyUltraviolet AstronomyUltraviolet AstronomyHigh-Energy AstronomyX-ray Telescope DesignChandra X-ray ObservatoryGamma Ray AstronomyGamma Ray AstronomyMulti-wavelength Milky WayFull Spectrum CoverageChapter 6Views of Our Solar SystemSun + Planets to Scale (sizes)Solar System: Distances to ScaleOur Solar System – Outer ReachesOur Solar System – Outer ReachesSolar System InventorySolar System InventoryExtraSolar System InventoryExtraSolar System InventoryPlanetary TerminologyPlanetary TerminologySolar System Density GradientTerrestrial PlanetsCompositional GradientTo Scale Model of the James Webb Space Telescope (JWST)Courtesy of Northrop GrummanJWST (6.5 m) vs. HST (2.4 m)Credit: NASAJWST will operate from long wavelength visible (orange-red) through the near-infrared to the far infrared (0.6 – 27 µm)Course Announcements•Exam 1 grading underway–Expected return date: Wednesday, 5 Oct.•Current scores will go on Blackboard as I finish grading the exams•Four EC Observing Opportunities this week•No Class Friday [Fall Break]AssignmentsReading Assignments•Chapter 16. Sections 16.1 – 16.3[Read by Wednesday, 5 Oct.]Parallel Lectures•CC Astronomy: Episode 10: The Sun[Watch by Monday, 10 Oct.]Mastering Astronomy•Chapter 5 Homework[Due Tuesday, 4 Oct. at 11:59 PM EDT]Space-Based AstronomyMost wavelengths require being outside of Earth’s obscuring atmosphereAtmospheric Opacity: How much is the atmosphere like a window or like a wall?100% Opacity = Wall (Space required) 0 % Opacity = Window (Ground okay)Gamma Ray X-ray UVVisible Near IR Mid-far IRMicrowave Radio Long RadioSpace-Based Astronomy - IR•Can use the same telescope design as optical telescopes•Requires specialized detectors (Not CCD-based)•Allows us to peer through the dust which blocks visible wavelengths (short IR wavelengths)•Allows us to study the dust directly at longer IR wavelengthsShort wavelength Infrared radiation can penetrate dusty regionsSpace-Based Astronomy - IRLonger wavelength Infrared radiation (8 – 100s µm) allows us to see the structure of dusty regionsSpace-Based Astronomy - IR•Can see star regions and higher density regions of dustLonger wavelength Infrared radiation (8 – 100s µm) allows us to see the structure of dusty regionsSpace-Based Astronomy - MicrowavesThe Planck Spacecraft measured the entire sky in microwaves to investigate the oldest light in the UniverseSpace-Based Astronomy - MicrowavesShorter wavelength microwaves (millimeter) allows us another view of the cold dust that pervades interstellar spaceCredit: ESO/APEX/A. Hasar et al.The Microwave GalaxyAPEX Telescope has recently provided our first view of what the Milky Way Galaxy looks like at submillimeter wavelengthsUltraviolet Astronomy•Basic design of UV telescopes similar to Visible and Infrared Telescopes•Useful for studying the gas between the stars (The Interstellar Medium, or ISM)•Useful for studying very hot, young stars and identifying Star Formation Regions (SFRs)Few nm to 400 nmUltraviolet AstronomyUltraviolet AstronomyCredit: NASA/Apollo MissionsThe Earth in Ultraviolet LightUltraviolet AstronomyCredit: NASA/SDO/AIAHigh-Energy Astronomy•High-energy, shortwave lengths makes it so traditional telescope designs and detectors fail–X-ray telescopes use nested cylindrical mirrors to focus X-rays via grazing angle reflections (Grazing Incidence Mirror Telescopes)–Directly counts photons instead of using CCD devices•Useful for studying extremely hot gas (millions of Kelvin)–Heated by exotic sources: Black Hole Accretion disks, supernovae, active galactic nuclei, etc.•Relative to other wavelengths, there are very few High Energy photons in the UniverseX-ray and Gamma Ray ObservatoriesX-ray Telescope DesignUses nested cylindrical mirrors to focus X-rays via grazing reflectionsChandra X-ray ObservatoryLaunched in 1999Supernova Remnant Cassiopeia A.Gas is 50 million K and different colors indicate different energies and different heavy elementsGamma Ray Astronomy•Detectors simply count photons hitting them.–Poor angular resolution at ~1 degreeNo current way to focus Gamma RaysSupernova RemnantGamma Ray AstronomyThe complete list of sources for Gamma Ray Bursts (GRBs) is still unknown, but have been linked to events such as the birth of black holes and merging events between supermassive black holes.Supernova RemnantThe energy of a GRB is enormous. In about 10s a typical Gamma Ray Burst can release as more energy than our Sun will over it’s entire 10 billion year lifetimeMulti-wavelength Milky WayFull Spectrum CoverageThe full spectrum coverage of the Milky Way.Astronomers aim toward having a full spectrum coverage available for simultaneous observations. A goal that has yet to be realized.CHAPTER 6The Solar System: Comparative Planetology and Formation ModelsViews of Our Solar SystemPlanetary Realm: 0.4 AU – 30 AU30.1 AUAsteroid BeltSun + Planets to Scale (sizes)Be able to list all eight planets in order!Solar System: Distances to ScaleGreat scale model solar system links:“To Scale: The Solar System” – a video by Wylie Overstreet and Alex Gorosh.- Sun to Neptune scale model in the Nevada desert.“If the Moon were 1 pixel” – a webpage by Josh Worth.Back to the football field analogy of day 1, lecture 10SunMercuryVenusEarthMars1.32.33.35.0Jupiter SaturnUranusNeptune17.3 31.7 64.0100.00Our Solar System – Outer ReachesOuter Oort Cloud~ 1,500 - 50,000 AUInner Oort Cloud~100s - 1,500 AUKuiper Belt: 30 – 55 AU Scattered Disk: 30 – 100+ AUPlanetary Realm0 – 30 AUOur Solar System – Outer ReachesNote the logarithmic scaleWhoever made this graphic must hate Mercury and VenusCredit: NASA JPLSolar System Inventory•Stars: 1 - The Sun (99.8% of the Solar System’s mass)•Planets: 8–Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune•Dwarf Planets: 5–Ceres, Pluto, Haumea, Makemake, Eris•Moons: 181•Asteroids: Estimated Millions – More than 200 over 100km in diameter. Over 600,000 discovered•Comets: Estimated Billions – About 4,000 discoveredPlanets, dwarf planets, moons, small
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