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So a total lunar eclipse happens
when the sun, the Earth,

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and the moon are aligned.

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The moon goes around the Earth
once a month, but we don't get an eclipse

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every month.

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Because the moon's orbit is a little bit
tilted.

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We get that alignment
about every six months.

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And so the Earth's shadow stretches across
240,000

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miles and lands on the moon.

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The great thing about a lunar eclipse
is that you don't need

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special equipment, and you don't need
to be in a particular location.

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Everybody in the United States
is going to be able to see this.

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They just need to go outside
and locate the moon.

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So Lunar Reconnaissance Orbiter,

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or LRO, has been in orbit around the moon
since 2009.

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It's been making global maps of the color
and the shape of the moon.

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The temperature for,
some forms of radiation from the moon.

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And so we're learning a lot
about what it's made of, more

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about where it came from.

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And therefore where the earth,
how it formed.

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And we're also learning
the shape of the terrain

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to a level of detail that will allow us
to land there safely and explore.

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Well,

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I'm maybe you can tell I'm old enough
to remember the Apollo era.

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And we went there for a few years.

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We landed astronauts on the moon.

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We gathered a bunch
of really important samples.

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And then there was sort of a quiet period
for a while.

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We're now going back with,
not only NASA itself,

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but its commercial partners
to sample the surface and explore.

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And the moon is a great destination
for this

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because it remembers
everything that has happened over

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the 4.6 billion years
the solar system has been in existence.

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This is how we can find out where
we came from, where the earth came from,

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where the moon came from,
how the solar system formed.

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And so I think that's really exciting.

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We've only

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landed people in 5 or 6 different places

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on the moon, and those places
were all near the equator.

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We're now sending both people and robots
to all kinds of places,

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including the South Pole,
that we haven't explored yet at all.

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The great thing about the South Pole
is that it

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can trap, volatiles like water.

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Trap it is ice that may have been there
for a billion years.

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And this is a great way
to sample the history of the solar system.

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But it also means that we might be able
to find ways to sustain

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a human presence on the surface.

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Right, exactly.

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So in order for us to create a sustain
presence on the moon with people,

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we need to know as much as possible
about what it's like there.

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What resources are available?

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What the illumination is going to be like
if we land at the South Pole?

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The sun is never more than a degree
and a half above the the horizon.

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The lighting situation
is very unusual there.

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So we need to gather as much information
as we can in order to plan those missions

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and make them as productive
and survivable as possible.

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So pi is this incredibly important number
in mathematics and science.

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It's just the ratio of the circumference
of a circle to its diameter.

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But it shows up
in all kinds of other places.

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So when I do eclipse calculations
to figure out

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where the shadow is going to fall,
that involves trigonometry.

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And all of trigonometry is built on pi.

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Now Pi Day is March 14th.

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It just so happens
that the first three digits of pi or 3.14

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and so the third month
and the 14th day becomes pi day.

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And this lunar eclipse
is going to happen on Pi Day.

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That happens once every 350 years or so.

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So it's quite unusual.

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It's a fun way to celebrate
not just the moon,

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but, math and pi.

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Of both kinds.

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So think of fruit pies
and pizza pies and all kinds of things,

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that you can

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add to your observation of the moon
and your celebration of science.

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So I mentioned this before.

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The eclipses don't happen every month
because the moon's orbit is tilted

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by about five degrees.

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And so some months during the full moon,
it's going to pass a little bit

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above the Earth's shadow.

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And some months
it's going to pass a little bit below.

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But about once every six months
it actually passes through the Earth's

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shadow.

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Now, it doesn't
hit the middle of that shadow every time.

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So some lunar eclipses are just partial.

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But every year or year and a half,
we on average,

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we get a total lunar eclipse
where the moon passes through the center

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of the Earth's shadow, and every part of
the moon is blocked from the sun.

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I will absolutely
be outside watching this eclipse.

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The best thing about a lunar eclipse
is that it's beautiful.

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So the moon during totality will turn
shades of orange and red and brown.

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It's being, hit by all of the sunrises
and sunsets projected from the Earth.

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And those colors will change over time.

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And the moon will be dim enough

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that it kind of looks almost transparent.

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This is something I've noticed over,
watching the past few.

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Total lunar eclipse is that it
almost seems to be disappearing

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like the Cheshire Cat.

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So it's an unusual thing to watch.

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It's.

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It lasts for an hour,
so you have plenty of time

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to look around
and see what other effects there are.

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And it makes you think about our place
in the solar system.

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I mean, we're standing at night.

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Every night
we're standing in the shadow of the earth.

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But on this particular night,
we get to see that shadow

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its extent all the way across space
from here to the moon.

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And so it's a it's just a lovely thing
to watch and to think about.

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The moon remembers everything.

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You know, on the Earth,
all of this is erased by weather

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and tectonics
and all kinds of things that make,

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cratering events
and other things, just go away.

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But all of that's remembered on the moon.

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And so we can look at craters that were
formed three and 4 billion years ago

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and learn about what was going on
in the early solar system from that.

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And I think that's just very cool.

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To learn more about the moon

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and about this eclipse,
go to science dot nasa.gov slash moon.