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Horizons Exploring the Universe 15th edition

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Michael Seeds and Dana Backman
Publisher: Cengage Learning

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  • Horizons Exploring the Universe 15e
  • Horizons 15e Virtual Astronomy Labs Course Pack

Access is contingent on use of this textbook in the instructor's classroom.

  • Chapter 1: Here and Now
    • 1.1: Where Are We?
    • 1.2: When Is Now?
    • 1.3: Why Study Astronomy?
    • 1: Digital Only
    • 1: Learn It
    • 1: Learning to Look
    • 1: Problems
    • 1: Review Questions
    • 1: Digital Workbooks

  • Chapter 2: A Guide to the Sky
    • 2.1: The Stars
    • 2.2: The Sky: Its Motions and Cycles
    • 2: Digital Only
    • 2: Learn It
    • 2: Learning to Look
    • 2: Problems
    • 2: Review Questions
    • 2: Digital Workbooks

  • Chapter 3: Cycles of the Sun and Moon
    • 3.1: Cycles of the Sun
    • 3.2: Astronomical Influences on Earth's Climate
    • 3.3: The Changeable Moon
    • 3: Digital Only
    • 3: Learn It
    • 3: Learning to Look
    • 3: Problems
    • 3: Review Questions
    • 3: Digital Workbooks

  • Chapter 4: The Origin of Modern Astronomy
    • 4.1: Prehistoric Astronomy
    • 4.2: Classical Astronomy
    • 4.3: The Copernican Revolution
    • 4.4: Planetary Motion
    • 4.5: Galileo Galilei
    • 4.6: Isaac Newton and Orbital Motion
    • 4: Digital Only
    • 4: Learn It
    • 4: Learning to Look
    • 4: Problems
    • 4: Review Questions
    • 4: Digital Workbooks

  • Chapter 5: Light and Telescopes
    • 5.1: Radiation: Information From Space
    • 5.2: Telescopes
    • 5.3: Observatories on Earth: Optical and Radio
    • 5.4: Airborne and Space Observatories
    • 5.5: Astronomical Instruments and Techniques
    • 5: Digital Only
    • 5: Learn It
    • 5: Learning to Look
    • 5: Problems
    • 5: Review Questions
    • 5: Digital Workbooks

  • Chapter 6: Atoms and Spectra
    • 6.1: Atoms
    • 6.2: Interactions of Light and Matter
    • 6.3: Understanding Spectra
    • 6: Digital Only
    • 6: Learn It
    • 6: Learning to Look
    • 6: Problems
    • 6: Review Questions
    • 6: Digital Workbooks

  • Chapter 7: The Sun
    • 7.1: The Solar Atmosphere
    • 7.2: Solar Activity
    • 7.3: Nuclear Fusion in the Sun
    • 7: Digital Only
    • 7: Learn It
    • 7: Learning to Look
    • 7: Problems
    • 7: Review Questions
    • 7: Digital Workbooks

  • Chapter 8: The Family of Stars
    • 8.1: Star Distances
    • 8.2: Apparent Brightness, Intrinsic Brightness, and Luminosity
    • 8.3: Stellar Spectra
    • 8.4: Star Sizes
    • 8.5: Star Masses—Binary Stars
    • 8.6: A Census of the Stars
    • 8: Digital Only
    • 8: Learn It
    • 8: Learning to Look
    • 8: Problems
    • 8: Review Questions
    • 8: Digital Workbooks

  • Chapter 9: The Formation and of Stars and Planets
    • 9.1: The Interstellar Medium
    • 9.2: Making Stars from the Interstellar Medium
    • 9.3: Young Stars and Disks
    • 9: Digital Only
    • 9: Learn It
    • 9: Learning to Look
    • 9: Problems
    • 9: Review Questions
    • 9: Digital Workbooks

  • Chapter 10: Stellar Structure and Evolution
    • 10.1: Stellar Structure and Nuclear Fusion
    • 10.2: Main-Sequence Stars
    • 10:3: After the Main Sequence
    • 10.4: Lower-Main Sequence Stars
    • 10.5: The Evolution of Binary Systems
    • 10: Digital Only
    • 10: Learn It
    • 10: Learning to Look
    • 10: Problems
    • 10: Review Questions
    • 10: Digital Workbooks

  • Chapter 11: Supernovas, Neutron Stars, and Black Holes
    • 11.1: The Deaths of Massive Stars
    • 11.2: Neutron Stars
    • 11.3: Black Holes
    • 11.4: Phenomenal Cosmic Powers
    • 11: Digital Only
    • 11: Learn It
    • 11: Learning to Look
    • 11: Problems
    • 11: Review Questions
    • 11: Digital Workbooks

  • Chapter 12: The Milky Way Galaxy
    • 12.1: Discovery of the Galaxy
    • 12.2: Structure and Components of the Galaxy
    • 12.3: Spiral Arms and Star Formation
    • 12.4: Origin and History of the Milky Way Galaxy
    • 12: Digital Only
    • 12: Learn It
    • 12: Learning to Look
    • 12: Problems
    • 12: Review Questions
    • 12: Digital Workbooks

  • Chapter 13: Galaxies: Normal and Active
    • 13.1: The Family of Galaxies
    • 13.2: Measuring the Properties of Galaxies
    • 13.3: The Evolution of Galaxies
    • 13.4: Active Galactic Nuclei and Quasars
    • 13.5: Disks, Jets, Eruptions, and Galaxy Evolution
    • 13: Digital Only
    • 13: Learn It
    • 13: Learning to Look
    • 13: Problems
    • 13: Review Questions
    • 13: Digital Workbooks

  • Chapter 14: Modern Cosmology
    • 14.1: Introduction to the Universe
    • 14.2: The Big Bang Theory
    • 14.3: Space and Time, Matter and Gravity
    • 14.4: Twenty-First-Century Cosmology
    • 14: Digital Only
    • 14: Learn It
    • 14: Learning to Look
    • 14: Problems
    • 14: Review Questions
    • 14: Digital Workbooks

  • Chapter 15: The Solar System: A Cosmic Family Portrait and History
    • 15.1: The Great Chain of Origins
    • 15.2: A Family Portrait of the Solar System
    • 15.3: A Recipe for Planets
    • 15: Digital Only
    • 15: Learn It
    • 15: Learning to Look
    • 15: Problems
    • 15: Review Questions
    • 15: Digital Workbooks

  • Chapter 16: Earth and Moon: Bases for Comparative Planetology
    • 16.1: A Travel Guide to the Terrestrial Planets
    • 16.2: Planet Earth
    • 16.3: The Moon
    • 16: Digital Only
    • 16: Learn It
    • 16: Learning to Look
    • 16: Problems
    • 16: Review Questions
    • 16: Digital Workbooks

  • Chapter 17: Mercury, Venus, and Mars
    • 17.1: Mercury
    • 17.2: Venus
    • 17.3: Mars
    • 17.4: Comparative Planetology, Once More
    • 17.5: Space Age Astronomy
    • 17: Digital Only
    • 17: Learn It
    • 17: Learning to Look
    • 17: Problems
    • 17: Review Questions
    • 17: Digital Workbooks

  • Chapter 18: The Giant Planets
    • 18.1: A Travel Guide to the Outer Solar System
    • 18.2: Jupiter
    • 18.3: Saturn
    • 18.4: Uranus
    • 18.5: Neptune
    • 18: Digital Only
    • 18: Learn It
    • 18: Learning to Look
    • 18: Problems
    • 18: Review Questions
    • 18: Digital Workbooks

  • Chapter 19: Small Solar System Bodies
    • 19.1: Asteroids
    • 19.2: Comets
    • 19.3: Meteoroids, Meteors, and Meteorites
    • 19.4: Pluto and the Kuiper Belt
    • 19.5: Impacts on Earth
    • 19: Digital Only
    • 19: Learn It
    • 19: Learning to Look
    • 19: Problems
    • 19: Review Questions
    • 19: Digital Workbooks

  • Chapter 20: Extrasolar Planets
    • 20.1: Expecting Exoplanets
    • 20.2: Finding Extrasolar Planets
    • 20.3: Exoplanet Properties: The Solar System in Context
    • 20.4: Earth-like Exoplanets
    • 20: Digital Only
    • 20: Learn It
    • 20: Learning to Look
    • 20: Problems
    • 20: Review Questions
    • 20: Digital Workbooks

  • Chapter 21: Astrobiology: Life on Other Worlds
    • 21.1: What is Life?
    • 21.2: Life in the Universe
    • 21.3: Intelligent Life in the Universe
    • 21: Digital Only
    • 21: Learn It
    • 21: Learning to Look
    • 21: Problems
    • 21: Review Questions
    • 21: Digital Workbooks

  • Chapter VAL: Virtual Astronomy Labs
    • Lab 1: Measurement and Unit Conversion
    • Lab 2: Light and Matter
    • Lab 3: The Doppler Effect
    • Lab 4: The Solar Wind and Cosmic Rays
    • Lab 5: Planetary Geology
    • Lab 6: Tides and Tidal Forces
    • Lab 7: Planetary Atmospheres
    • Lab 8: Extrasolar Planets
    • Lab 9: Kepler's Laws
    • Lab 10: Helioseismology
    • Lab 11: Stars, Star Clusters, and the HR Diagram
    • Lab 12: Binary Stars
    • Lab 13: Stellar Explosions, Novae, and Supernovae
    • Lab 14: Neutron Stars and Pulsars
    • Lab 15: Asteroids and Kuiper Belt Objects
    • Lab 16: Astronomical Distance Scales
    • Lab 17: Evidence for Dark Matter
    • Lab 18: The Hubble Law
    • Lab 19: The Fate of the Universe
    • Lab 20: Stellarium Labs
    • Lab 21: Stellarium Labs

Questions Available within WebAssign

Most questions from this textbook are available in WebAssign. The online questions are identical to the textbook questions except for minor wording changes necessary for Web use. Whenever possible, variables, numbers, or words have been randomized so that each student receives a unique version of the question. This list is updated nightly.

Question Availability Color Key
BLACK questions are available now
GRAY questions are under development


Group Quantity Questions
Chapter 1: Here and Now
1 0  
Chapter 2: A Guide to the Sky
2 0  
Chapter 3: Cycles of the Sun and Moon
3 0  
Chapter 4: The Origin of Modern Astronomy
4 0  
Chapter 5: Light and Telescopes
5 0  
Chapter 6: Atoms and Spectra
6 0  
Chapter 7: The Sun
7 0  
Chapter 8: The Family of Stars
8 0  
Chapter 9: The Formation and of Stars and Planets
9 0  
Chapter 10: Stellar Structure and Evolution
10 0  
Chapter 11: Supernovas, Neutron Stars, and Black Holes
11 0  
Chapter 12: The Milky Way Galaxy
12 0  
Chapter 13: Galaxies: Normal and Active
13 0  
Chapter 14: Modern Cosmology
14 0  
Chapter 15: The Solar System: A Cosmic Family Portrait and History
15 0  
Chapter 16: Earth and Moon: Bases for Comparative Planetology
16 0  
Chapter 17: Mercury, Venus, and Mars
17 0  
Chapter 18: The Giant Planets
18 0  
Chapter 19: Small Solar System Bodies
19 0  
Chapter 20: Extrasolar Planets
20 0  
Chapter 21: Astrobiology: Life on Other Worlds
21 0  
Total 0  

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