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Do you forget the difference between a solar and lunar
eclipse, too?
One looks like this.
And the sunny day suddenly becomes dark.
And the other is a full moon that gets darker and darker.
A lunar eclipse is when the moon is blocking the light
from the sun.
Wait a minute.
No.
I changed my mind.
See?
It's not just us.
Here are three different ways to remember which is which.
Some of the confusion probably comes
from not knowing exactly what the word eclipse means.
It's an obscuring of the light from one celestial body.
So the name of the eclipse tells you
which one is getting darker.
In a solar eclipse, the sun or Sol in Latin, get darker.
In a lunar eclipse, the moon or luna in Latin, gets darker.
Solar eclipse, sun is eclipsed.
Lunar eclipse, moon is eclipsed.
Easy.
The name of the eclipse also tells you
which thing to look at if you want to see the eclipse.
If I want to see a solar eclipse,
I look at the sun with specially designed glasses
so I don't burn my retina.
If I want to see a lunar eclipse,
I look at the moon with my bare eyes.
That's fine.
If you just can't remember the names,
and you really want to know what's
going on with a solar and lunar eclipse, here's what.
A solar eclipse is when the sun gets
blocked because the moon is passing
between Earth and the sun.
The moon blocks light from the sun, casting a shadow on Earth.
You could even do this at home.
Get a ball for the moon and the Earth and a flashlight
to represent the sun.
Looking from Earth, we want to block the light from the sun
so the moon must pass between the two.
See that?
You can see the shadow cast on Earth.
And from Earth, of course, we would see an obscured sun.
So during a solar eclipse, the order goes sun, moon, earth.
A lunar eclipse is when the moon gets darker,
because the Earth passes between the sun and the moon.
So Earth's shadow is cast on the moon.
Try this at home by passing Earth between your flashlight
and the moon.
Now looking from Earth to the moon,
we see the shadow of Earth.
During a lunar eclipse, the order of the bodies
is sun, earth, moon.
So now you have a useful little chant.
Solar SME, lunar SEM.
Sorry.
Now that you know which eclipse is which,
we can talk about the cool stuff,
like the fact that if you were on the moon,
a lunar eclipse would be a solar eclipse.
What?
Think about it.
If you were on the moon, and the Earth
passed between the sun and you, you
would see the sun go away, because you'd
fall into Earth's shadow.
But now from your point of view, that's a solar eclipse.
Pretty cool, but not as cool as the stuff
you can figure out if you know when
an eclipse is happening, like what phase the moon will be in.
During a total lunar eclipse, what phase is the moon in?
Ah, it'll be a full moon.
I-- full.
WOMAN: What about during a solar eclipse?
It's a new moon.
So the moon would have to be new.
You can also figure out what the tide will be.
During a lunar eclipse, what are the tides doing?
They are maximal.
During a lunar eclipse, still gonna be high tide.
So a full moon happens every 29 days or so.
Then why don't we see lunar eclipses all the time?
Well, the orbit of the moon is on a slight tilt
compared to the orbit of Earth around the sun.
So at this time of year, when the Earth
is between the moon and the sun, it
won't be a direct line between all three.
When the earth moves over here, though,
the full moon position creates a straight line,
putting the moon right in Earth's shadow.
The same happens when we move Earth over here.
If there are two lunar eclipses in the same year,
they happen about six months apart,
because that's this time between the correct positions
for a lunar eclipse
Cool, huh?
But it's not exactly six months in between.
In fact, it's always about 177 days.
Why do you think it's not exactly six months?
OK.
One more question for ya.
There are about the same number of total lunar
and total solar eclipses that happen, about 60 every 100
years or so.
But we see lunar eclipses so much more often.
Why is that?
Well, it has to do with the size of the shadow involved
in the eclipse.
The Earth is so much bigger than the moon
that when it's shadow is cast on the moon,
the entire nighttime side of the Earth
can see the eclipse unless it's cloudy.
On the other hand, the shadow cast by the moon
is more like this.
It's a lot smaller.
So the solar eclipse is only visible to this small portion
of the Earth, the part in the moon's shadow.
In fact, it's so unlikely for this to happen,
the same part of the Earth will see a total solar eclipse
about once every 375 years.
This is what the path of the upcoming eclipse in 2017
will look like.
Only those within that narrow band
will be able to see the total solar eclipse.
That's it for sweet facts about eclipses.
[SLURPS] Real sweet.
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Thanks for watching!
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