44 NEBRASKAland • AUGUST-SEPTEMBER 2017
O
n Monday, Aug. 21, throngs of people across
Nebraska – and the United States – will be treated
to a sight that, for many people, seems to defy
description. Hotels and campgrounds across the state have
been booked solid for months by travelers from across
the globe hungering for the sight. What is it? A total solar
eclipse, the first on American soil since 1991, and the first to
sweep across the entire country since 1918.
To learn more about the eclipse, I visited with Dr.
Rebecca Harbison, a professor of practice of astronomy at
the University of Nebraska-Lincoln, to learn more about
this once-in-a-lifetime event. The information she provided
excited me even more.
What is a total solar
eclipse?
An eclipse happens
when you have the sun,
the moon and the Earth
all lined up. And a solar
eclipse occurs when the
moon is between the Earth
and the sun. So from the
Earth's point of view – or
at least for some part of
the Earth – the moon is
blocking the sun. Or you
could think of it as, the
moon's shadow is falling
on the Earth.
How rare is a solar
eclipse?
You might think solar
eclipses should happen
every month, since the
moon orbits the Earth. But
they don't because the
moon's orbit is slightly
tilted compared to the
Earth's orbit around the
sun. Most months, the
moon passes above or
below the sun in the sky.
Only about twice a year do
we get a solar eclipse.
In addition, the moon's shadow on the Earth is really
small – at least the dark part of the shadow, the umbra, the
place where the moon covers the whole sun and not just part
of it. It's only about 50 miles across, more or less. So even
though we have maybe two solar eclipses a year, most of the
Earth that sees the eclipse will only see the partial eclipse.
Only a small patch of Earth will be in the line of totality.
What's special about this particular eclipse?
One reason we make such a fuss about this eclipse is that
the line of totality is crossing the United States from Oregon
to South Carolina. Because the Earth is mostly covered in
ocean, sometimes a total eclipse can be really hard just to
get to.
Historically, eclipses have caused great panic, viewed as omens
of death and destruction from the gods.
By Renae Blum
Total Eclipse
of the Sun
ILLUSTRATION
BY
C.
N.
GOCHIN
PHOTO
BY
STEPHEN
MUDGE