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Astronomy: Observations & Theories
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| Video Lesson 1:
The Study of the Universe This lesson takes students on a journey from planet Earth to the distant galaxies and superclusters. It is illustrated with stunning computer animation and photographs from NASA, the Jet Propulsion Laboratory (JPL), and astronomical observatories. This journey introduces the planets, stars, and galaxies that will be presented and discussed throughout the course. |
Video Lesson 11:
Stellar Remnants This lesson describes the fascinating objects that remain after the deaths of large stars?neutron stars and black holes. Gamma-ray bursts and hypernovae are presented as some of the most energetic objects in the universe. |
| Video Lesson 2:
Observing the Sky Explaining the concept of a scientific model, this lesson introduces the celestial sphere as a model to help describe and organize the night sky. Several specialists explain how different cultures named stars and constellations, and brought the aspects of the sky into their buildings and structures, such as those of Chaco Canyon in the southwestern United States. |
Video Lesson 12:
Our Galaxy: The Milky Way Most discussions of galaxies begin with our very own Milky Way. This lesson presents the history of the study of the size and scale of our galaxy and our place in it. The anatomy of the galaxy is introduced and the mapping techniques are unveiled. |
| Video Lesson 3:
Celestial Cycles This video lesson explains the motion of Earth around the sun and its yearly cycle. Astronomers explain the unique orbital and size relations between the rotation of Earth, the sun, and the moon and how this makes a total solar eclipse possible at predictable intervals, known as the Saros cycle. The lesson concludes with a description of the ecliptic and explains how that differs from constellations that are contained in the zodiac. |
Video Lesson 13:
Galaxies This video lesson looks at the classification of galaxies in general, and discusses the fact that, when these ?island universes? were discovered, how the perceived size of our universe increased immensely. It goes on to describe distance indicators and introduces the Hubble Law. The lesson ends with interaction and evolution of galaxies and with a sneak peek into the furthest depths of the universe. |
| Video Lesson 4:
The Birth of Astronomy A presentation on the foundations of astronomy, The Birth of Astronomy examines the observations, theories, and contributions of Aristotle, Ptolemy, and other ancient scientists and philosophers. Copernicus, Tycho Brahe, Kepler, Galileo, and Sir Isaac Newton?s contributions are discussed throughout this lesson. |
Video Lesson 14:
Active Galaxies The discussion of galaxies continues in this lesson by focusing on a special group of galaxies with very energetic cores called active galaxies. Different types of active galaxies are introduced, from Seyfert galaxies and blazars to quasars. |
| Video Lesson 5:
Astronomical Tools Astronomers are the only scientists who do not manipulate the objects they study. Instead, they do two basic things: collect light and analyze it. Accordingly, this lesson answers two basic questions: (1) What is light? and (2) What tools are used to collect it? |
Video Lesson 15:
Cosmology Some of the most profound questions are asked and discussed in the complex subject of cosmology. What shape is the universe? How did it begin? How will it end? Evidence is presented that supports the big bang theory, and the exciting notion of dark energy is introduced. |
| Video Lesson 6:
The Science of Starlight Students will discover the interactions of atoms and light and what spectra can tell us about a star. The fascinating history of spectral classes and the intriguing group of women who were responsible for much of our stellar classification system today is also presented. |
Video Lesson 16:
Solar Systems Opening with a survey of the solar system and an examination of the solar nebula theory that explains how our solar system was formed, this lesson also reviews how the spinning solar nebula formed a disk of dust particles that eventually became the planetesimals that formed the planets. The actual detection of planets around distant stars is given considerable coverage, with experts describing the newest techniques and the successes achieved. |
| Video Lesson 7:
The Sun?Our Star This lesson describes the thermonuclear process in the core of the sun, identifying the layers of the interior and atmosphere showing spectacular pictures of surface features, such as granulation and sunspots. The magnetic cycle and magnetic effects on the surface are also introduced. Discussions of how the sun affects Earth?s climate conclude the lesson. |
Video Lesson 17:
The Terrestrial Planets Using Earth as the archetypical example, this lesson details the stages of differentiation, cratering, flooding, and surface evolution. The impact of plate tectonics is presented as the formation and evolution of Earth is detailed. Comparisons are continuously made to the other terrestrial planets. |
| Video Lesson 8:
The Family of Stars To determine how bright a star actually is, we need to know how far away it is. This lesson illustrates how to find distance to nearby stars and how to plot them on an H?R diagram. It also shows why binary stars are important for the study of stars and their mass?luminosity relation. |
Video Lesson 18:
The Jovian Worlds This lesson begins with an explanation of the processes that allowed the planets in this part of the solar system to grow to such large sizes. How the gravity of Jupiter produces tidal heating of Io and Europa, causing the extensive volcanic activity on Io and a liquid ocean beneath the surface of Europa is explained. Saturn?s interior and atmosphere are compared with those of Jupiter. The formation and characteristics of the ice giants Uranus and Neptune are also discussed. |
| Video Lesson 9:
Stellar Births The study of stellar evolution is presented by examining the birth of stars. Different types of nebulae are introduced and the necessary ingredients to produce a star: dust, gas, gravity, and maybe a little push are discussed. The mass?luminosity relation is reintroduced and suggests the role that mass will play in the life and death of a star. |
Video Lesson 19:
Solar System Debris This examination of solar system ?debris?: meteorites, asteroids, and comets concludes the exploration of the solar system. Astronomers explain the composition of the different types of meteorites and various theories about their origin. Images, including that of the Deep Impact Probe hitting Comet Tempel 1 in July of 2005, are used to illustrate the characteristics of comets as described by astronomers. The lesson also includes a discussion of the demise of the dinosaurs and the discovery of the crater in the Yucatán that may have been the impact site. |
| Video Lesson 10:
Stellar Deaths This lesson details the life and the death of stars. The fact that stars spend most of their lives on the main sequence consuming their nuclear fuel in a stable manner is detailed and illustrated, as well as how a star?s mass determines how quickly it consumes its fuel, how long it will live and how it will die. A presentation of the study of stellar remnants, the leftover products after a star dies, concludes the lesson and leads us to the topic of the next lesson, neutron stars and black holes. |
Video Lesson 20:
The Search for Life Beyond Earth Scientists discuss the possibility that the early seeds of life on Earth were delivered by comet impacts and the reasons why it is believed that the first life began on the deep seafloor near hydrothermal vents. The discussion continues with a look at Europa?s subsurface ocean and the pros and cons of life forming in that hostile location. The life zone or habitable zone of a star is defined and the efforts to detect signatures of that life using future spacecraft missions are described. The efforts and difficulties of communicating with an intelligent extraterrestrial civilization are discussed. |
