>> From the Library of
Congress in Washington, D.C.
>> Dr. Alex Young from NASA Goddard.
And he's going to talk about
the total solar eclipse of 2017.
And I need say no more, let's go.
>> Dr. C. Alex Young: Okay.
So thank you for your patience.
I apologize for getting stuck in
traffic, especially given that I was
at NASA headquarters,
which is almost walking --
well, it is walking
distance, really, so.
And I have visitors from
NASA headquarters here
from the planetary division,
solar system exploration.
So it's great to see you guys here.
So thanks, everyone, for coming.
As I said, I tend to move around, so
I have to force myself to stay still
because they're videotaping.
So I'm going to stay right here.
But what I'm going to talk
about today is something coming
up this summer, August
21st, total solar eclipse.
And I want to give you some of the
perspective from NASA's viewpoint,
but all in all, this
is not a NASA event.
NASA's very used to
having their own launch
and things they have control over.
This is nature's event, and
NASA's just along for the ride.
But I want to give you some of the
things that are important to NASA
and that NASA's really just
trying to share to the public.
But all in all, this
is for everyone.
And the good thing is that
everyone can experience this
in some form or another.
Before I go forward, this is what
I'd like to do, is ask everyone
to imagine looking at this
blank slide; what do you think
about when you think about the sun?
On a daily basis, what comes to
mind when you think about the sun?
>> Hot.
>> Dr. C. Alex Young: Hot?
So maybe something
like this, you know?
Maybe a nice sunrise
or a nice sunset.
Or maybe even this, it's actually
so bright, it's hard to look at.
Even if you put a camera up, you
don't really see a whole lot.
You know, if you're lucky
enough to have a telescope,
then maybe you'll see something a
little more interesting like this.
So here you see these
objects called sunspots.
Just to give you some perspective,
these are the size of
the earth or bigger.
Okay? So the sun is
really, really big.
But the only other thing
you really get from this is
that you can see the sun rotate,
which is something
we don't really get
from our perspective
here on the ground.
Other than it moves in the sky, we
don't actually see that it rotates.
But this is actually
kind of boring, okay?
This not too exciting.
But what's going to happen on August
21st of this year is that if you're
in the right place, you're going
to see the sun slowly disappear --
looks like a Pac-Man for those
of us that remember Pac-Man --
as the moon moves in front of it.
And eventually you're going to
see it completely disappear.
And all of a sudden, this is
going to be replaced by it.
Instead of the bright disc of the
sun, the thing that we can't look
at with our own eyes, if
you're in the right place --
and I'll talk more about what I mean
by the right place --
this is what you see.
You see the outer atmosphere
of the sun.
It's incredibly dynamic.
It's wispy, sort of ethereal.
You can even see these features
at the top that are red.
These are things that you
can see with your own eyes.
And this is the sun that we know
really well, especially from space.
And it's an opportunity
during a total solar eclipse
to see the dynamic sun
from the ground in a way
that we cannot see even
with the most sophisticated
and amazing technology.
Nature gives us a glimpse
of this part
of the sun that's incredibly
dynamic and has huge implications
for the science that
we're interested in,
as well as it actually
has implications
for even our technological society.
And I'll talk a little bit more
later about that when I talk
about the science specific
to the eclipse.
But first, I want to talk a little
bit about what an eclipse is,
what makes this eclipse
kind of special,
and what actually makes eclipses
special and rare in general.
So one of the things to think about
is what's happening here simply is
that everything is
lined up just right
that the moon moves
in front of the sun.
It appears about the same
size as the sun in the sky
because of its location
and its orbit
and it blocks out the
disc of the sun.
But this doesn't happen
all the time.
It actually happens
during a new moon.
And you might think, "Well,
we get a new moon every month,
so why doesn't this
happen then, okay?"
So we're used to thinking
about in the month we have --
you know, once a month we
see there's a full moon.
You see there's also the new moon.
So why doesn't this
happen all the time?
Why don't we get this every month?
This is another view
of the different phases
of the moon's orbit.
Just to remind you, so
you're sitting on the side
of the earth that's lit
up by the sun, okay,
and there's the new moon --
the moon that is invisible,
you can't see it, from
the night side.
But in the day side that's
actually blocking the sun
out during a total solar eclipse.
But one of the things that's special
is that the orbit of the earth
and the sun make what we
call the ecliptic, okay?
But the orbit of the moon around
the earth is actually inclined
by about five degrees.
And so what that means is, is
every time it moves around,
it's not always in that plane.
Sometimes it's a little bit
higher than the plane of the earth
and the sun, and sometimes
it's a little bit lower.
So this is what you see.
Sometimes you get the situation
like the top where it's
above the earth or
also below the earth.
And so this shadow
that's cast by the sun --
I'm sorry, by the moon
from the sun shining
on it is actually not
hitting the earth.
But there's a special time
when you actually have
that shadow that's
cast on the earth.
And that's what's happening
during an eclipse.
But there's also one
other part of it.
Not only is the orbit
of moon inclined,
the orbit's actually not a circle.
So sometimes it's a little bit
farther away from the earth,
sometimes it's a little bit closer.
So it has an elliptical orbit, a
football sort of shape or oval.
And so I won't go into
a lot of detail,
but what that actually also means
is even when the shadow is lined
up just right, there are times
when the moon is actually
farther from the earth.
And so it actually is not
the same size as the sun,
it's a little bit smaller
than the sun.
And so in fact, you get an
eclipse but you get a type
of eclipse called an
annular eclipse.
So you see this ring of
fire people often call it
around the edge of the moon.
But we're interested in
the case where it's closer
and it completely blocks out the sun
-- that's the total solar eclipse.
So that's the special
one that we want to see.
So what's going to
happen on the 21st?
So we're looking from
behind the moon.
And you can see that there's
a shadow cast from the moon.
And that dark circle
is called the umbra --
that's the dark center
of the shadow.
And if you're in that path where
that dark circle travels from,
starting in Oregon, all the way
across down to South Carolina,
you will see a total solar eclipse.
But everyone in North
America, Central America,
and a portion of South America is
going to be in that bigger circle
around it -- we call
that the penumbra --
and that's where it's
partially blocked
and you'll still see
a partial eclipse.
So everyone in the United
States, North America, Central,
and part of South America
is going to see
at least a partial solar eclipse.
And that includes here.
So, again, here's kind of this
series of what you would see.
There's the partial eclipse,
the moon slowly moving
in front of the sun.
Just before we get to
what we call totality
where the moon is completely
blocking out the sun,
light will shine through
the edges of the moon.
So the moon is actually not a
nice, smooth sphere; but in fact,
it has mountains and craters.
And one of the things that we
actually have been able to do
with technology from NASA using
the LRO spacecraft is actually map
out that surface in
incredible detail to allow us
to see what's going to
be cast on the earth.
Because it turns out that it's
actually not a simple circle
or even an oval, but in fact, it's
actually a complicated polygon.
So it's crazy, the shadow actually
has, you know, sharp edges.
Something that when
people first simulated it,
didn't actually believe it.
They thought the computers
were lying to them,
that they were seeing errors.
But in fact, it's because the
moon has all this structure
around the edge.
And so when the sun
is shining behind it,
light is shining through
those valleys.
And that's what happens right before
totality, you get this glimpse
of a flash, often called the diamond
ring or even the engagement ring.
Sometimes you'll see
several of them,
which are called Bailey's beads.
And that's when the light is shining
through the valleys on the moon.
So here's another perspective.
This is the shadow.
So I'm showing you across the
country you're seeing as the shadow,
as the umbra is moving, that
shows you how partiality --
how the partial eclipse
changes across the country.
Now, of course, where the
partial eclipse disappears,
that's right where that black
dot is and that's where all
of a sudden you have totality.
So it starts at around
10:30 local time in Oregon,
travels across the country at about
1,200 to 1,500 miles per hour.
It's moving incredibly fast.
It gets to South Carolina just
close to 3:00 p.m. local time.
And that time period of
totality from coast to coast is
about an hour and a half.
Now, the partial phase
-- seeing partiality --
is actually many more hours.
So that's going to last for three to
four hours across the whole country.
And if you're in that
path, if you happen to be
in that region we call the path of
totality, it's about 70 miles wide,
then you have somewhere between 30
seconds if you're on the edge of it,
and if you're near the center of it
-- we call that the center line --
it's going to be about two to
two and a half minutes roughly.
So that's how much totality you get.
Okay? And when that happens, this
is kind of what you would see
from the ground just
looking at the sun.
Now, I'll emphasize this a
couple of times, and I know many
of you have probably
heard this many times:
You should absolutely never
look at the sun with your eyes
without the proper protection.
This is especially the
case for everywhere
that there's only a partial eclipse.
Okay? So always remember that.
The only exception to this is if
you are in the path of totality,
that brief time period of
half a minute to a couple
of minutes is the only
time you can look
at the sun with your naked eyes.
Because you're seeing
the outer corona,
which is a million times dimmer
than the disc of the sun.
The sun itself is so incredibly
bright that even when 98% or 99%
of it is covered by the moon,
it's still too bright to see.
Okay? It still can do
damage to your eyes.
I'll talk a little
bit about the ways
in which you can look at it safely.
But I just want to emphasize that
because that's really paramount --
safety is first and foremost.
But this is the sequence
you would see.
This is a sequence -- and
actually, the reason the sun is kind
of reddish is actually
that has a filter on it
until it gets to totality.
And that's when they
actually take the filter off.
So one of the things that
I'll talk about later again is
that when you're looking up at
the sun during the partial phase,
as soon as it gets dark when
you're in the path of totality,
that's actually when you
take your glasses off.
And that's when you're seeing
the total solar eclipse.
Okay? But what is it
really going to look
like if I zoom in, okay, closer in?
This is what it's going
to look like.
So let me tell you a
few things about this.
So this is a digital
image, a photograph.
And in fact our eyes do
a better job than this.
This does not do it justice
in terms of what you see.
Now, this is zoomed in some.
It will be a bit smaller from
your perspective on the ground.
But you will see more detail
than you can see in here in terms
of that wispy structure
around the edge.
Now, closer to reality -- now,
this is actually taking it
several images together --
it will look more like this.
Again, this is zoomed in, but you
will see more structure and detail
like this because our eyes
have much more dynamic range.
They can see much more
variation in the light,
in the fainter light
structures that you will see.
So here is just a quick --
I'm going to talk quickly
about the safety aspect again, and
then I want to talk a little bit
about what's special about this
eclipse and put it in perspective
with eclipses in general.
So a couple of things.
So there's two ways to view the
partial part of the eclipse.
One is to directly look at it
but not with your naked eyes,
with glasses specially
designed for this.
They're usually called safe solar
viewing or eclipse viewing glasses.
Those are the ones
that I've put outside.
I brought about 200 pairs.
So everybody should
at least get one,
and we can always help you get more.
And there's also lots of
them across the country
at libraries, community centers.
NASA has worked with a lot of other
organizations and we have millions
and millions of them
out in the public.
So there's no shortage of these.
I know the people printing
them are working faster
than 24/7 to get these done.
So you can do that.
You can even buy special glasses.
They're a little more expensive.
They're not paper ones.
There are even companies
that make binoculars
that have filters on them.
But I want to emphasize:
Never use these glasses
with binoculars together.
That's actually very dangerous.
Because in fact, binoculars are
telescopes, will amplify the image
of the sun, amplify the light,
and will damage these glasses.
Also, if the glasses slip off while
you're looking through binoculars
or a telescope, it's
even more dangerous
than just looking directly.
So don't ever use these --
you can only use binoculars
that actually have filters built
into them or specially
designed filters.
But the other way to look at is
it because you probably don't want
to stare up for four hours while
the partial phase is going on.
You're going to get
tired of doing that.
But you don't have to do that.
You can actually use what we call
indirect or projection methods.
So any kind of pinhole will do.
It will project a little
small image of the sun.
You'll see the crescent as
the moon moves across it.
I'm actually going to
take a colander with me.
I'm going to wear a colander,
put it over, and it's going
to make lots of cool images.
You can get -- we actually
ourselves and several other
of our colleagues have
produced postcards
that already have holes
put into them.
You can project it with
actually a mirror, a little,
small mirror and an envelope.
We've got this on our website,
which I'll list the website later.
But there's also the trees.
The trees themselves when the leaves
cross will make their own type
of little pinholes and you'll see
these really cool shadows projected
on the ground.
The first time I saw that,
it was really amazing.
I looked down and there
were all these shadows,
but all the shadows are,
like, little crescents.
It's a really, really cool effect.
And you can actually take
a box like a cereal box,
you close all the parts of it,
inside you can put a
piece of white paper.
On the other side you make a big
hole, you put a piece of tinfoil,
tape it over, poke a hole in that.
And on the other side you make a
hole that you can look through.
So you have the sun this
way and you would look
down with the sun behind you,
project through the pinhole,
into the box, and then you
can look through and see it.
You can do that with
larger boxes, too.
So there's a lot of
different ways to do that.
And there's a lot of great
information on our website,
which I'll show again,
as well as colleagues
like the AAS have a really fantastic
website with all this information.
So let's talk about
eclipses in general.
So why are -- you know, even though
we have these issues with the orbit,
they make it so the eclipses don't
happen every month, we get some kind
of eclipse every six months.
But actually, for total
solar eclipses,
we get on average a total
solar eclipse somewhere
in the world every 18 months.
But the problem is the
world is really big.
So those eclipses are
happening everywhere,
but they're mostly happening
over water or over places
where there are not a lot of people.
So that's the first reason that
this eclipse is really special.
Because it's happening from coast to
coast over the United States, okay,
over the lower 48 states.
A lot of people live there,
and a lot of people are going
to get to experience it.
So that's one of the reasons
that this is really exciting.
It's happening over such a large
piece of land that's populated,
and it's going to basically be
happening over an hour and a half.
So in some ways we -- I'll talk
a little bit more about this --
but we're going to have not two
minutes of observations, but an hour
and a half of observations.
Here's another perspective from a
colleague who makes fantastic maps.
This is just to show you, again,
they're happening all over,
but they're happening in places
where there are just
not a lot of people.
So this particular eclipse
also is pretty interesting
for several reasons.
Now, this is a collection
of all the eclipses
in the US from 1776 to 2017.
So a couple of features about
this particular eclipse.
This is the first coast to
coast eclipse since 1918, okay?
This is the first total solar
eclipse in anywhere in the US
since 1991, but that was Hawaii.
The previous one was in 1979
in the northwestern part
of the United States over
about, I think, four states.
The next one that is going to happen
in the United States is
actually going to be in 2024.
But one of the things that's
interesting to add to what's kind
of cool about this particular
eclipse is the path for the one
in August is going to -- the one
in 2024's going to cross that.
So in Carbondale, Illinois the
eclipse seven years later is going
to cross the one that's
happening in August 21st.
On average eclipses
happen at the same location
on the globe every about 375 years.
There's another one, 2045, that's
going to cross the one in 2024,
and it's going to cross
it farther south.
So this is pretty cool.
The odds of this are pretty rare.
So these are some of the reasons
that make this particular
eclipse pretty exciting.
So here's zooming in on just the
ones that are going to be happening
over this year, 2024, and
2045 just to show you.
So you can see where
they cross each other.
So that's a pretty rare
and pretty exciting thing.
Actually, I was mentioning
Carbondale,
they like to call it the
crossroads of the eclipse.
I was actually going
to be in Carbondale,
but now I'm not going
to be in Carbondale.
So I just got my plans
changed on me, so.
But that's going to be
pretty exciting for folks
that will be there because
they'll get to see it again
in just seven years
in the same place.
So here's a summary of
the path across the US.
And we have maps at
NASA on our website,
which is Eclipse2017.NASA.gov.
And all of these maps
are made along with lots
of different visualizations like the
one I showed you to give you tons
of different perspectives
of what's going on.
And one of the things
that's really cool
about this is these maps were made
using a lot of data from NASA.
So that's one of the things
that's sort of exciting,
is that all the data that we're
able to gather, we're using it
to provide the most
accurate results.
I won't go into the details
because it's a talk unto itself.
But I mentioned the fact that the
shadow itself is not an ellipse
or not a circle.
And in fact, using the
data, for example, from LRO,
the Lunar Reconnaissance
Orbiter, we've been able
to provide the most accurate maps of
the shape of the shadow as it moves
across the country, as well as where
the actual edge of totality is.
Because the issue there is that
even if you're right at the line
where totality is, all you have to
do is step right over and outside
of it and you're not in totality.
Okay? So knowing where that line is,
you're fine if you're in the center.
But when you get close to the edge,
the precision actually matters.
Now, I will add just a little
caveat, there actually are a lot
of eclipse hunters that are
interested in staying close
to the edge because you see
more structure and change,
more of these Bailey's beads, as
well as the diamond ring effect
when you're close to the edge.
So there they really want to make
sure that they know where they are.
So a couple of things
about the people
that are going to see this eclipse.
So this is a map showing you how
many people live within 50, 100,
up to 500 miles of the eclipse.
So it turns out that majority of --
depending on how fast you drive --
I mean, I think I can probably
drive 12 hours in a day.
But even sort of an average
driver, a good proportion
of the population lives
within driving distance
of the path of totality.
So it's going to be a
really interesting event.
I'll just add that the reality is
that we actually don't know
how crazy it's going to be.
And it's something that people are
very interested in finding out.
And I've talked to a lot of
folks at DOT, the Department
of Transportation, and
they're very interested
in seeing what's really going to
happen when people try to get there.
I can guarantee you that people
who wake up the morning and go,
"There's eclipse today," and try
to get there are out of luck.
Probably the people who wake
up the day before and try
to get there are out of luck.
And certainly depending
on where you are.
But there's going to be a lot of
people who wake up and go, "Hey,
I just heard there's a total solar
eclipse, let's go check it out,"
and it's 20 miles away and
they're not going to get there.
So if you are planning on going,
that's one thing to remember,
something we try to emphasize
again and again: Plan ahead.
This is like Woodstock 200 times
over but across the whole country.
Okay? So in terms of logistics,
make sure that you have
sunscreen, it's going to be August.
It's going to be hot everywhere.
Make sure you have water, food.
But if you have an opportunity
to go see this, take it.
Because you will not
be disappointed.
If you're interested in going to
see it, here's an average map.
There are some more updated ones.
NOAA just put out one.
I've actually been trying to
sort of sort through the results.
But this is one from last year.
This is an average map to
show you the cloud cover.
So you can see that, of
course, basically west
of the Mississippi it
gets better and better.
Places like eastern Oregon, Idaho,
Wyoming, those are the best places.
As you start to get over
towards the East Coast it starts
to get a little bit more dicey
in terms of the cloud cover.
I'm actually now going to be
in Charleston, South Carolina.
So I grew up in the South.
I know that at 2:00 and 3:00
o'clock, that's thunderstorm time.
So we'll see.
But it is close to the coast, and
that does make a difference, too.
So real brief, I don't like
to put a lot of words up.
But just a couple of things.
These are sort of the things that
are really important to NASA.
Now, why does NASA care?
Well, first and foremost, one of
the things that's very important
to NASA is communicating
science, communicating what we do.
Because everything that
we do at NASA is yours.
Okay? We work for the country to
explore the reaches of science,
technology, our solar
system, and beyond.
And so sharing that knowledge
is paramount and part
of the fundamental edict of NASA.
But in terms of the eclipse,
safety is first and foremost --
safety in terms of viewing
and safety in terms of going
to the events and making sure
that you've really planned ahead.
Science, I'm going
to talk about that.
Education, it is a huge
education opportunity.
I'm not going focus so much on that,
but that is something that folks
that I work with have spent
a lot of time thinking about.
This has been a really interesting
challenge to both, you know,
how do we reach and take this as an
opportunity to talk about, you know,
orbits, and the sun, the moon,
the whole sun/earth/moon
system, and even the earth?
Because one of the things
I'll touch on briefly is
that this is actually a unique
opportunity to do earth science --
not just sun and moon,
but actually earth.
There's some unique opportunities,
which I'll talk about.
So these are some of the
science that we're interested in.
Of course, there's the sun.
There's observing it
from the ground,
observing from earth,
studying the moon.
Actually, in this case LRO is going
to have the advantage of looking
at the shadow from the moon.
And that's a really,
really amazing opportunity.
This is a way to connect to other
types of science that we do,
not necessarily directly.
But eclipse is a special type
of what we call a transit
where one object moves in
front of another one --
a planet moves in front
of a star or a moon moves
in front of another planet.
Within our solar system,
using transits
and eclipses is a very important
way in which we study those objects.
And beyond that, it's a critical way
that we study things
like exoplanets.
And that's actually how we find
exoplanets is by transits, okay.
Now, I'll add one thing here.
I'll talk a little bit more
about some of the earth science.
But actually, something I just found
out a couple weeks ago, actually,
my colleague in the audience
came up with a brilliant idea.
We're going to be flying
balloons around the country.
I think it's 57.
So 57 high-altitude balloons.
And these balloons are going to go
in a range of 60,000 to 80,000 feet.
So that's generally to look down at
the earth, we'll look at the shadow
to see the changing environment.
But it's about the pressure --
it's equivalent to
basically the atmosphere
that you experience on Mars.
Okay? So what the idea was is
you take these little packets
that have bacteria --
and I apologize if I don't
say it exactly right --
but put these little packets with
bacteria and actually send them
up in the balloons to
study what happens.
Because ultimately, we want to
know, you know, is there life --
are the components of
life or is there even life
in the solar system beyond earth
or even beyond our solar system?
So one of the places that it's
critical to study this is Mars.
So this is an opportunity
to actually connect
with our neighbor planet
and study the environment.
So I think it's really cool.
And it's what we call a mission
of opportunity or an experiment
of opportunity where we added
something onto something
that was already happening.
But I'm going to focus for
a short bit on the sun.
This actually happens
to be my area of study.
I'm a solar physicist.
And the eclipse, as I
mentioned, is an opportunity
to really study a unique
and critical part
of the sun's atmosphere, the corona.
Okay? So, you know, I showed
you those images of the sun.
They weren't too exciting,
except for the eclipse image.
But you know what?
If we step outside into space, okay,
we step outside of the atmosphere --
right now we see the sun from the
ground in a very narrow region,
a narrow band of light
-- mostly visible light,
a little bit of UV infrared.
But it's a small portion of the
entire electromagnetic spectrum.
You know, light goes from microwaves
and radio waves all the way
to X-rays and gamma waves.
And it's huge changes
in the amount of energy
and the characteristics
of that light.
And that tells you lots of different
things depending on which kind
of light you're looking at.
But when we go out into
space and we look at the sun,
we see something very different.
This is the sun that we see.
Can we turn these lights
down a little bit?
We can't? Okay.
Well, what you're seeing here is
the sun in extreme ultraviolet.
And hopefully you can see --
I have this dying urge to run
over to this image and touch it.
But you see all this
activity happening, okay?
You're seeing huge explosions.
You see that flash of light?
That's called a solar flare.
That is enough energy is released
in that flash of light over a period
of a few minutes to hours to power
the entire world for 100,000 years.
Okay? But not only do you
have that flash of light,
the sun is also expelling huge
blobs of itself and magnetic field
and solar material are
flying off into space
at millions of miles an hour.
And all of this stuff, all of this
energy and material is filling
and bathing the entire solar system.
And it creates an entire
environment as this --
all this stuff coming off the
sun interacts with the planets,
with comets, with asteroids, with
everything in our solar system.
Here's another example
from the same spacecraft.
So you're seeing these
huge eruptions many,
many times the size of the earth.
Okay? That thing, when it
gets to its farthest expanse,
it's about 15 earths from the
edge of the sun to the top of it.
And that's billions of tons of
solar material that are flying off.
So this area, all of
this action that you see,
all this stuff happening on
the sun happens in the corona.
It happens in this region of the sun
that we see during a
total solar eclipse.
Okay? And I won't go
into all the details,
but basically what's happening
is the sun is a giant ball
of electrified gas.
And inside of it, it
has magnetic fields.
These are the same magnetic
fields that make a magnet stick
to your refrigerator, okay?
But these are huge and
much, much stronger.
But these magnetic fields are
kind of like little rubber bands,
except they're really,
really big rubber bands.
When you twist them and
twist them and twist them --
if you take a rubber band, you twist
it and twist and it and twist it,
eventually it will start to knot up.
At some point you're going to
twist it enough it's going to pop.
And when it pops, it
actually releases energy.
The same thing happens
with magnetic fields,
they have a similar
property: They get all twisted
and they release that energy.
And that's what's creating that
solar flare and that big blob
of stuff flying off the sun.
And so all that structure that you
saw in those images of the corona,
that's actually magnetic field.
They're invisible, but the corona
itself actually highlights them.
You can see them.
And understanding what's happening
there is telling us why this is
happening and helping us
to understand not only
why it's happening,
but how do we predict this?
The ultimate reason is because all
of this stuff is interacting
with all of the planets.
And it's part of the fundamental
environment that we have
to understand, but also this
stuff is electromagnetic, okay?
It responds to electricity
and magnetism.
And what in our society responds
to electricity and magnetism?
Technology.
And so we have satellites
in space, we have GPS,
we have communication systems,
we even have power grids
on the ground -- all
of them interact
with this stuff that
comes off the sun.
And sometimes these
explosions can be large enough
that they actually can knock
out our communications,
it can disable spacecraft.
It actually creates an
incredibly harsh environment
in space for astronauts.
So we need to understand
that environment not only
around the earth, but
traveling to places
like Mars understanding this
environment is critical.
And in the worst case scenario
we have seen in the past
when power grids went down
because of these solar eruptions.
So these are all the reasons
why we have to understand it.
So we can make artificial
eclipse in space
and you can see this
material coming off.
But the problem is
you see that circle --
that's actually where the sun is.
Because even though we can
make these eclipses in space,
we can't do as good a
job as the moon does
with the earth and the sun.
This is the eclipse I showed you,
and that area from the black disc
out to that white line
is that area outside
of this white disc
that we don't see.
So you're seeing that from the
ground we see this whole area --
actually, the most important
region for space weather
and solar activity, we only see this
invisible light from the ground.
So what that means is we
have a unique opportunity
to see the eclipse and see what's
happening on the sun in a way
that we normally couldn't see even
with the most sophisticated
spacecraft.
Now, back to what makes
this eclipse special.
Normally an eclipse at any one
location is only two minutes or so.
But think of this like having
a camera following a player
down a football field
or a soccer field.
You have a string,
the camera follows it,
and you can see the
action all the way.
We can't quite do that because
we can't follow the shadow that's
moving at 1,500 miles per hour.
But we can line up lots of cameras
along the path, lots of telescopes,
and even lots of balloons to
study as this thing moves along.
We can put all that data together.
And now instead of having
a two-minute observation,
we have an hour and
a half observation.
And we can finally see things
that are happening here.
Now, there are lots of other
things that are exciting.
One of the things we're going to
do is we're testing technology
on the ground that we'll
eventually put into space --
that's an important thing.
Because you want to test
things before you fly them.
So that's another opportunity.
And I'm glossing over the details.
But the other part
is the earth part.
So the eclipse itself, when that
shadow is moving across the country,
where it hits, it gets dark --
about as dark as a moonlit night,
the temperature drops five, ten,
more degrees; the winds change;
animals become quiet or freaked
out; this whole eerie structure.
You look around, you're
sitting inside this shadow
and every direction is
dusk all the way around.
So it creates a really
amazing local environment.
And that local environment
moves across the country.
So that's one of the things we're
doing, is we're actually looking
at how the environment, how
the climate, how the animals,
how the plants, how
everything reacts
as it it's moving across
the country.
And because it's going over
such a huge piece of land,
we can study many different little
mini-environments all together.
So that's kind of the
earth perspective.
So we're doing huge amounts of
science, looking at the shadow
from the moon; the looking at
the corona from the ground;
looking at the earth, seeing how
it changes both down on the ground
and even from balloons above and
even spacecraft are looking down --
earth observing spacecraft
are following this.
So this is an opportunity
to bring together all
of these different
ground-based observations,
space-based observations and
get a holistic big picture.
Not just one snapshot here or there,
but to see all of what's happening
from all these different
vantage points.
And that's really where
NASA is bringing
in all the things that
it has to offer.
It's bringing in all of these
different assets and helping
to bring them all together,
working with many different partners
from different government agencies,
universities, private industry --
all of these are coming together
to bring all this science
for this unique opportunity.
So let me wrap up with --
this is actually a map,
and this map actually is now out
of date, it changes so quickly.
But this is just showing you
NASA along the path is going
to have NASA TV crews that
will be taping at local places
where they'll be observing the
eclipse, having activities.
We're going to have observations
from aircraft starting
at the beginning of the eclipse.
We have a boat from the Coast
Guard at the end of the eclipse
that will be launching a balloon.
We also have lots of educational
activities along the path,
and we're coordinating
with many different people.
So all of this will
be brought together
in a big broadcast from NASA TV.
And then NASA TV will also be
bringing in through NASA.gov lots
of webcasts from all
these different locations.
And it includes webcasts from
every one of those 57 balloons.
So what's going to be seen
from all those balloons
at 80,000 feet will be broadcast
live down to the NASA website.
So to find out more, you can
go to the NASA website --
actually, hold on, it's telling
me to connect to the Wi-Fi.
So Eclipse2017.NASA.gov.
I'll also add that
next week on Wednesday,
the 21st of June is a news press
conference from the Newseum
that will be broadcast by NASA TV.
We'll have partners from NOAA,
from the National Park Service.
I didn't add that actually some
of those sites you see are
actually park service sites.
We'll have members of
some other agencies there,
as well as many different
experts from around NASA to talk
to the press, to tell
everybody about what's going on.
This has been a huge opportunity.
If you go to this website, you can
find maps, Google Maps with links
to all of the different activities
that are happening
across the country.
We have groups -- for example,
there are 1,500 libraries
that are connected through
one of our partners.
And there's also lots of educational
materials, as well as maps,
all of the materials that you
can get today is on the site
and downloadable for free.
And then you can find out
what's going on and any changes
that are happening for the event.
So lastly, be safe, plan
ahead, and have fun.
Enjoy and watch the show.
And if you can't be in the path
of totality, there's going to be
so much coming out from NASA,
from our colleagues at places
like the Exploratorium
that hopefully you'll
get to experience it.
And it's just going to want to
make you go to the 2024 eclipse.
[ Applause ]
>> For those who don't
have to run off,
I guess we could take
a couple questions.
And if you would repeat
the questions.
>> Dr. C. Alex Young: Yes, ma'am?
>> You mentioned being
concerned about binoculars;
what concerns about
photographs or [inaudible]?
>> Dr. C. Alex Young: Well, as long
as you're not looking through --
there's a lot of information out
there about how to do it correctly
in terms of digital photography.
Colleagues like Fred
Espenak and others have books
and websites on how to do it.
You're going to want to
use filters, for example,
during the partial phase
because you're not going
to see anything but
a big bright image.
But there are lots of
different things you can do.
You can do projection
methods and all this.
So there are many different
options for doing photography.
Now, the one thing
I'm going to add --
this is something that all the
eclipse experts have said to me time
and time again -- unless
you're really,
really set on doing photography --
there is going to be
some amazing photography.
And if this is the first
eclipse you've ever seen,
don't waste your time
doing photography.
It's two minutes, maybe less,
maybe a little bit more.
Put your camera down,
look up, and enjoy it.
And enjoy what's happening
around you
because there will be
other opportunities.
>> So I have studied the sun and
eclipses and ancient history.
What's your favorite reference in
ancient history for [inaudible]?
>> Dr. C. Alex Young: Oh gosh.
I don't know, there's a
lot of really cool myths.
I always like there's one about -- I
mean, I guess a lot of the myths are
about different animals
that are eating the moon.
There's some really cool stories.
And actually, what I liked
most was seeing how stories
from India traveled through
different cultures and evolved
and actually get to Siberia.
So you can actually see how
the different stories evolved
for the cultures, but
they're all the same story.
So I think that's actually one
of the things I like the most.
And the Vietnamese frog
that eats the eclipse.
I like the frog.
So but I think that's one
of the coolest things.
There's a lot of really
great storie, though.
Yes, sir?
>> 1919 Eddington, was that
a solar or lunar eclipse?
>> Dr. C. Alex Young:
It was a solar eclipse.
Yeah, so referring to
Eddington looking at the eclipse
in the 1900's was actually
one of the first verifications
of general theory of relativity.
So it's actually great because we're
down at the hundred-year
anniversary of general relativity.
So he looked at both the
apparent location of a star
versus its actual location
because of the bending
of light by gravity of the sun.
So it's a really, really neat,
neat experiment that he did.
>> Somebody else?
>> Dr. C. Alex Young: Yeah, let me
make sure I get somebody else first.
Go ahead.
>> You said we couldn't
filter the sun out as well
as the moon does, why is that?
Why can't we do it in
space or on the ground --
[ Multiple Speakers ]
>> Dr. C. Alex Young:
Well, it's optical issues
with defraction of light.
I mean, when you put the
disc to block out the sun,
the closer the disc
is to the camera,
you're going to get defraction
around the edge of it.
And with the moon/earth/sun
system, the distances are
so huge you don't get
the defraction issues.
So it's just a geometric
optics problem, basically.
Now, we're looking at how to
make spacecraft with, you know,
large separations -- that's
certainly been done in other places
like X-rays where you need
to have long distances.
So I think that's something
that might happen in the future,
more than likely will, and
we'll just see how good we do.
>> Show them your shoes.
>> Dr. C. Alex Young: Oh.
>> Solar flare shoes.
[ Multiple Speakers ]
[ Laughter ]
>> Dr. C. Alex Young: So you
have a question over here.
>> Yes, [inaudible] how do
the solar flares happen?
>> Dr. C. Alex Young: Solar flares?
>> Yes.
>> Dr. C. Alex Young: Oh,
okay, that's a great question.
So -- well, it's kind
of a statistical thing.
But they follow an activity cycle.
So just like we have hurricane
cycles of roughly a year and,
you know, we have a peak during
the end of the summer/beginning
of the fall, the sun has
a cycle of going from low,
high, to low roughly 11 years.
Okay? Sometimes a little shorter,
sometimes a little longer.
So we have solar flares all
the time, but as you get closer
to the peak, you get
more and larger ones.
What's that?
Yeah, we're getting close
to the bottom right now.
The peak was around 2013.
There are actually two humps.
There's actually two peaks.
The north and south part of
the sun have different peaks.
But we're getting close to
solar minimum right now.
It's kind of unfortunate, but
there are different things --
the structure of the corona
changes during the solar cycle.
And so that's actually a
really interesting thing.
So even if we don't have a lot
of activity and we don't see,
let's say, an eruption happen during
the eclipse, seeing the structure
of the corona change from
the solar physicist point
of view is really, really important.
And actually, some things
we've seen is it's different
than we've expected, actually.
Did you have another question or?
>> Does that mean the
2024 [inaudible]?
>> Dr. C. Alex Young: Yes.
[ Laughter ]
And that's the cool thing.
I mean, I'm glad you
brought that up.
Because that means we have
two eclipses very close,
a long period of observation,
and we can see two different
parts of the solar cycle.
So that's a fantastic question.
I'm glad you brought that up.
Yes, sir?
>> [Inaudible] questions.
I just read a report stating that
most stars come into existence
with a twin, come in pairs --
stars come into existence as pairs;
does our sun have a
twin and where is it?
>> Dr. C. Alex Young:
Not as far as we know.
I mean, it is the case that
they're doing more binaries.
Now, actually, I had
somebody tell me this morning
that there's some sort of
story going around about this.
I haven't checked it out.
But we do not have a twin star.
>> Okay. And if you do
find it, you will put it
up on the website, right?
[ Laughter ]
>> Dr. C. Alex Young:
Oh, we certainly will.
We certainly will.
>> Okay.
>> Dr. C. Alex Young: Yes, ma'am?
>> How will cloud cover affect
viewing so we [inaudible]?
>> Dr. C. Alex Young: Well,
so that's a good question.
So how will cloud cover
affect viewing?
Now, it will affect viewing.
I mean, maybe you may not see the
actual eclipse, but you're going
to see the light levels change, the
animals are still going to respond,
the temperature's still
going to change,
the environment is
still going to change.
So even if you don't see
the eclipse itself --
and I may have a huge risk of that
happening where I'm going to be --
you still get to experience
the whole event.
So don't worry, you're still going
to get something spectacular
from it.
Yes, sir?
>> Do scientists know why it's
every 11 years or 8 years or 9?
Or why is the cycle --
>> Dr. C. Alex Young: That's
a really great question.
The simple answer is no.
We actually know -- what we think we
know the process inside the sun is
called a dynamo, okay,
which is a process
of how we actually think the
magnetic fields are generated inside
things like planets like the earth,
a liquid core, sort of similar.
When liquids that are conducting
spin, they create magnetic fields.
We are pretty sure that's
happening inside the sun,
but we don't completely
understand the physics.
And we can create a
dynamo, but we can't get it
to give us the right number,
you know, 11 years or 8 years.
And we know it changes.
We see other stars that have
cycles that are different.
But right now we can't get
it to be exactly 11 years.
So we don't really have
a self-consistent theory.
Yes, ma'am?
>> You had mentioned about
animals being affected
by the eclipse, what happens?
What do they do?
And is it better if the
animal is sensitive not
to have them experience the eclipse?
>> Dr. C. Alex Young: I
don't think there's --
I mean, I'm not an expert on this.
I don't think there's anything
dangerous about it for animals.
Basically you can imagine if
you're sitting somewhere and all
of a sudden it gets dark real quick
and you have no idea why and all
of a sudden the temperature
changes and it feels like nighttime,
you're going to react to that.
In the simplest terms, the animals
are responding to they're all
of a sudden in nighttime
very quickly.
And so that's probably a little
bit disturbing for it to happen
so quickly, but it's also
they're just responding
to a totally different
environment --
suddenly they think it's nighttime.
But I don't think it's
anything dangerous.
I mean, I'm not going to hide my
cats or anything like that, so.
Yes, sir?
>> I saw that happen in 1970.
>> Dr. C. Alex Young: Oh, cool.
>> And it was very strange.
The birds just all of a
sudden headed for the trees.
>> Dr. C. Alex Young: I mean,
there's a lot of really
good stories.
There's actually on our website, on
the eclipse website, we have a video
from a colleague, Doug Duncan,
who's seen a lot of eclipses.
And he's got a really nice video
about different animal experiences.
He told me a story of
once he was on a ship.
And when the totality hit,
whales and dolphins surfaced
and just looked up and didn't
do anything during totality.
And then as soon as it was over,
they went back to their business.
He said it was pretty eerie.
>> They had their little
glasses on, right?
>> Dr. C. Alex Young: Yes, ma'am?
>> Can you talk about shadow bands?
>> Dr. C. Alex Young:
I don't know a lot
about shadow bands, unfortunately.
I can certainly -- I've
got some great books
and some great colleagues
I can point you to,
but unfortunately I
don't really know a lot.
Do you know anything
about shadow bands, Jim?
Yeah, I don't know
anything about shadow bands.
Shadow bands is this
really cool striation effect
that you see during eclipses.
And it's not just total eclipses;
you can see shadow bands, I think,
during annular eclipses, too.
But I'll be honest, I don't
really know a lot about it.
But I've actually got some books
with me right here that I brought,
one from Fred Espenak,
which is really good.
And he would know.
He's really cool.
I know he would be
the kind of person
that you could just send
him an email and ask him.
So sorry I can't tell you more.
>> I think we'd better
close this session.
>> Dr. C. Alex Young: Let
me answer one more question.
>> Is there going to be any
major ocean tide impact?
>> Dr. C. Alex Young:
I don't think so.
I mean, it's not going to be over
the ocean, first of all, that long.
But I can't imagine.
I'll be honest, I'm
not an expert on that.
But I really can't imagine
that there would be any reason
that there would be any
sort of change like that.
I'm sure there would
be tiny, tiny changes
but probably things we wouldn't
be able to easily measure.
Yeah. So, all right,
one more question.
>> Any advice on a place that's
not too crowded [inaudible]?
[ Laughter ]
>> Dr. C. Alex Young: Oh gosh.
Well, definitely stay
away from Oregon.
Maybe Idaho or Wyoming.
>> Oh, no, I've heard
lots of people --
[ Multiple Speakers ]
>> Dr. C. Alex Young: Yeah.
I don't know that there really is --
I mean, I just -- yeah,
I don't know.
I think the most determining factor
should be do you have a place
to stay that's within your budget?
Because a lot of places are
really, really gouging people.
It's actually been so
bad of an issue in Oregon
that the governor got involved.
Now, strangely enough, I was talking
to a colleague in South Carolina
and we were looking
online and there are a lot
of places available
in South Carolina.
Now, South Carolina is going
to be really populated.
But if you can get it --
I mean, frankly, if you can get a
hotel near the center of the path
of totality, I would just go there
and then step outside your
hotel room and see it.
Don't worry about all the frill.
Because there's a lot of
towns that have activities
and events and things like that.
But if you can make sure you can get
there and you can afford the hotel,
then go wherever you can go.
So the best thing to do is
to be as close as you can
to where you want to observe.
Because then you don't
have to worry about traffic
and all that kind of stuff.
>> What about airplanes?
>> Dr. C. Alex Young: Airplanes
-- actually, I have a colleague,
Mike [inaudible], you may be
familiar there's a video that came
out during the 2016 eclipse, which
was predominantly in Micronesia.
He was able to -- because he used
to work for CBS and had some pull,
he was able to convince
Alaskan Airlines
to change the path
of their airplane.
And so he flew -- they flew the
plane through the path of totality
and he made a video of it.
And he's famous for being
the "Oh, my God" guy.
Because he said oh my God
about 22 times, I think.
[ Laughter ]
And it was picked up by CBS,
became sort of a viral video.
He's a huge avid eclipse chaser.
He's been seeing eclipses --
when he was a kid he
went to the '79 eclipse.
So you can find ones
that are in the path.
It's not necessarily easy.
I will say if you're
truly interested in that,
my colleague Sten Odenwald,
who's amazing with numbers,
and he sat down and figured out
all the airplanes that were going
to probably be in the
path of totality.
So he's got a spreadsheet
of that, you know?
It looks really cool.
The video is amazing.
Now, of course, you won't
experience the environmental issues.
But they were above the clouds
and you can see the shadow coming
in a way that I've not
seen in any other video
because you don't have any of
the terrain to worry about.
So it was pretty spectacular.
So I actually looked into trying
to get on one of the NASA planes,
but all the high-upies were the ones
that get to be on the NASA plane.
I couldn't carry luggage or
anything like that to do it.
But it's worth a try, yeah.
>> One more?
>> Dr. C. Alex Young:
One more, okay.
>> What are the special
glasses made of?
>> Dr. C. Alex Young:
They're just made
of a particular type of plastic.
I don't know the details.
I will say the thing to note,
there's an ISO standard.
So the back of the
glasses should say ISO,
and I don't remember
the exact number,
but it should have
ISO standard on it.
Older ones will have CE --
that's a European standard that's
still acceptable.
But currently the ISO standard
is the international standard.
So if you go to our website,
we have a joint safety bulletin
with the AAS, NSF, and
the American Optometrist
and Ophthalmology Societies.
We list the four major
producers that we know.
They're not the only ones,
but they're the ones we
know are ISO certified.
And you can go to those.
They sell all kinds of glasses.
And places like Lunt, L-u-n-t,
are one of the people that I know.
They sell -- they're not the only
people -- but they sell, like,
the binoculars that actually
have the built-in filters.
And they're, like, $25 or something.
They're not that expensive.
So there's a lot of really
cool options out there.
So thanks a lot, everybody.
I really appreciate it.
Thanks for waiting for me, so.
[ Applause ]
>> This has been a presentation
of the Library of Congress.
Visit us at loc.gov.