The Universe & Galaxies SOL 14

The Universe & Galaxies
SOL 14
Fundamental Concepts and Skills
1. Many types of observations are needed to better
understand our universe.
 Much of our information about our galaxy and the universe comes
from ground-based observations, using optical and radar
telescopes as well as spectroscopes.
 The Hubble Space telescope has greatly improved our
understanding of the universe because it is located above the
earth’s atmosphere.
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2. Define a light year as the distance light travels in one year. It is
the most commonly used measurement for distance in astronomy.
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3. Explain that the Big Bang Theory and the solar nebular theory
are the best current hypotheses for the origin of the universe and
origin of the solar system respectively.
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4. Recognize that the Big Bang Theory states that the universe began
12-15 billion years ago as a dense sphere that expanded and
eventually condensed into galaxies.
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5. Understand that :
 Galaxies are collections of large numbers (billions) of stars.
 Identify the basic types of galaxies as spiral (have arms),
elliptical (round or oval shaped), and irregular.
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6. Understand that :
 Stars have a finite lifetime and evolve over time.
 The mass of a star controls its evolution, length of its lifetime, and
ultimate fate.
 Stars form by condensation of interstellar gas.
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7. The sun, like other stars, consists largely of hydrogen gas. Its
energy comes from nuclear fusion of hydrogen to helium.
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8. The solar system is located in the Milky Way Galaxy.
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