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Bright objects visible at large distances
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Objects above or below the plane – so not as
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obscured
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Ways to measure distances to those objects
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Ways to see material other than stars
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Gas, dust, ???, mass distribution
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Ways to map motion of objects in our Galaxy
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Examples of other Galaxies
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The Shapley-Curtis debate:
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Are spiral nebulae external galaxies or a type of object within
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our own galaxy
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