Wanna See the Solar Eclipse? Here's What You Have to Know

[Narrator] On August 21st,

darkness will wash over America.

But in a good way, we promise.

It's a total solar eclipse, the first to hit the US

mainland in almost four decades.

The shadow will cut a path 70 miles wide,

beginning in Oregon at about 10 a.m. local time.

From there, it'll move into Idaho and Wyoming,

then pass through the Midwest before leaving the US

through South Carolina at 2:45 eastern.

The total eclipse will only last a few minutes

in a given spot but if you happen to have a jet,

like NASA does, you can race the shadow.

In the name of science, NASA will be able to observe

the eclipse for seven minutes.

The best the rest of us schlubs can manage

is driving to the eclipse's path, but be forewarned,

a lot of people are going to have the same idea.

12 million people already live in the path of the eclipse

but as many as seven million

will make the trek to these areas.

Even if you can't make it to see the totality,

you'll be treated to a partial solar eclipse.

The closer you are to the path,

the more complete the eclipse will be.

At work here is a supreme astronomical coincidence.

The moon is of course much much smaller than the sun.

But because it's so much closer,

the two bodies actually appear to us observers on earth

as the same size, so when the moon passes in front

of the sun, it perfectly obscures the star.

(cheering)

What's important to remember is that while you can look

at a total solar eclipse without burning your eyes

out of your head, to watch a partial eclipse,

you're going to need special glasses.

These use a thin layer of aluminum or silver

to block the nasty energy coming off the sun.

You can get these any number of places online.

Don't you dare try watching without it.

After all, if you wanna watch the next solar eclipse

that'll hit the US in 2024, you're going to need to see it.

Or if you've been planning a South American getaway,

do it in 2019 for their next totality.

Just don't forget your shades.