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[Music]

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I’m Ernie Wright. I work in the Scientific Visualization Studio

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 at NASA’s Goddard Space Flight Center.

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We’re looking at a computer model

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of the view at the South Pole of the Moon.

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This is like a time-lapse to show the motion

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of the Sun and the Earth and how the shadows change over time.

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Things don’t rise and set in the usual way here.

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The sun travels around the horizon, never getting more

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than a degree and a half above or below it,

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so there are always these long shadows.

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And from here, the Earth appears to be upside-down

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and rotating backwards, but that’s just because of our point of view.

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The Earth doesn’t move much in the Moon’s sky.

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It’s always in roughly the same place, just sort of bobbing around.

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That’s true everywhere on the near side of the Moon.

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It’s a consequence of the Moon always pointing

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the same face toward Earth. 

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It takes about a month for the Sun

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to make a complete circuit around the horizon,

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and every so often, it’ll pass behind the Earth, creating an eclipse.

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I’ve slowed down time here a little so that it’s easier to see.

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On Earth, that would be a total lunar eclipse -

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the Moon passing through the shadow cast by the Earth.

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But if you’re standing on the Moon, it’s an eclipse of the Sun.

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The terrain at the South Pole is especially rugged.

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The rim of Shackleton crater is in the foreground here,

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and the mountain off on the horizon is unofficially known as

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Mons Malapert - it's about 85 miles away.

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Shackleton crater is about 13 miles wide,

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not quite as wide as the Grand Canyon, but it’s twice as deep.

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Sunlight never reaches the crater floor, so temperatures there

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are around 300 degrees below zero Fahrenheit.

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This model of the terrain is made possible

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by Lunar Reconnaissance Orbiter, which has been mapping

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the surface of the Moon from lunar orbit since 2009.

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LRO’s maps will be incredibly important for exploring the Moon

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and locating water and other resources there.

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[Music fades]