Program Information

Series: NASA Connect
Program: Dancing in the Night Sky
Segment Number: 5 (Watch entire program)
Duration: 00:06:26
Year Produced: 2003
Description:

NASA Connect Segment explaining what NASA is doing to explore auroras. The segment also answers questions like what are the phases of the Aurora and how scientists use satellite images to monitor auroras.

NASA CONNECT™ is a series of Emmy®-award-winning, math-focused programs. Each program supports the national math, science, and technology standards and has three components that include (1) a 30-minute television broadcast; (2) a companion educator's guide; and (3) an online activity that further explores topics presented in the broadcast. These programs establish a connection between the math, science, and technology concepts taught in the classroom to those same concepts used everyday by NASA researchers.

For more information visit: http://connect.larc.nasa.gov/

Transcript

Super job, you guys.

So what is NASA doing
to study the auroras?

Well, Nicky Fox,
a senior scientist
at the Johns Hopkins University
Applied Physics Laboratory
in Baltimore, Maryland,
can tell us all about it.

This is
the Johns Hopkins University
Applied Physics Laboratory,
in Laurel, Maryland.

I am the operations scientist
for the Polar Mission.

The Polar Mission is part
of NASA's
Sun-Earth Connections fleet.

Within the Sun-Earth
Connections fleet,
Polar has the responsibility
for multiwavelength imaging
of the aurora,
measuring the entry
of the material
into the polar regions,
the flow of material to and from
the ionosphere,
and the discharge of the energy
in the ionosphere
and the upper atmosphere.

Scientists use satellite images
to monitor the position
of the various auroral features.

In particular,
the latitudinal location
of the edge closest
to the equator of the aurora
determines the amount
of activity.

The further the aurora moves
towards the equator,
the bigger the event.

Also, the extent and speed
of the expansion of the aurora
tells us a lot
about the amount of activity.

The further and faster it moves,
the larger the event.

Polar is a unique spacecraft,
because it carries
four different cameras
to study the aurora.

There is a high-resolution
visible imager,
which allows us to look
at the aurora
in different wavelengths,
or colors.

In this way,
we can simultaneously image
the red, blue, and green
components of the aurora.

There is also a global imager,
which allows us to look
at the whole Earth at once.

This camera takes pictures
in ultraviolet
so we can see
what the aurora is doing
even when there is sunlight
in the way.

Auroras do occur
during the daytime;
we just can't see them
with the naked eye.

But from the images
of this camera,
we can see the size
of the auroral oval.

With all these cameras
and the data we collect,
we can photograph
the evolution of an aurora.

The evolution of every aurora
tends to follow
a similar sequence.

We call this
an auroral substorm.

The following images show
a typical sequence
of an auroral substorm.

The first image shows
a quiet oval
before any activity begins.

This is called the quiet phase.

Right before we see
any bright emissions,
we can observe the oval
getting bigger
and moves further
towards the equator.

This is called the growth phase.

The activity truly begins
with the small spot of light,
or onset event,
followed by the lighting up
of the whole ring
and an expansion
to a more poleward location.

The large, bright region
you can see
is called the auroral bulge.

When the aurora reaches
its maximum expansion,
you can see that the large bulge
begins to break up
and the small discrete features
appear.

Finally, the whole aurora
dims and recovers.

It will eventually return
to the initial state,
the quiet phase.

The whole process may repeat
over and over again
until the activity
dies out completely.

Now, all the images
you've seen so far
have been
from the northern hemisphere
of the northern lights,
or the aurora borealis.

But did you know
that there was also
a southern counterpart
of the aurora
called the southern lights,
or the aurora australis?

And here we're seeing
a unique movie
taken by the polar spacecraft
that shows us
both the north and the south
at the same time.

This allows us to see
that the activity is occurring
at the same time
in both hemispheres.

We call this
the conjugate aurora.

Now, we've seen data
from many different cameras
on the Polar spacecraft
and learned that when
you add them all together,
you can learn an awful lot more
about the aurora.

Now we're looking
at an animation
which shows the Polar
auroral image underneath
with the TIMED spacecraft
flying over the top.

TIMED is taking images
in very high resolution,
and you can see that every time
the spacecraft flies
through the oval,
it suddenly illuminates
all the fine-scale features
that you couldn't see before.

So now we know that when you add
two data sets together,
you get even more information.

Now with the addition of data
from ground-based observatories
and sounding rockets,
we can look at the aurora
with full perspective.

Virginia Standards

3rd Grade SOLs » Mathematics » 3.9
4th Grade SOLs » Mathematics » 4.7
5th Grade SOLs » History-Social Science » USI.6
6th Grade SOLs » History-Social Science » USII.1
8th Grade SOLs » Science » PS.9
9th Grade SOLs » Science » ES.3