46 NEBRASKAland • AUGUST-SEPTEMBER 2017
the sun entirely, and you'll get a ring of sun around the
moon. That's called an annular eclipse.
There are also lunar eclipses, but that's totally different;
that's when the moon is going into the Earth's shadow.
What solar features are visible during a total solar
eclipse?
During a total solar eclipse, what we see as the surface of
the sun, the photosphere, is covered. So we can see the
sun's outer atmosphere, the corona. It's so much fainter
that the only way to see it from Earth is to block the
photosphere.
Tell me more about the corona.
It's very thin, and surprisingly it's hotter than the surface
of the sun; the sun's magnetic field heats it to millions of
degrees. It streams off of the sun, and some of it escapes
the sun entirely, forming what we call the solar wind. It's a
stream of particles which occasionally causes things like the
aurora, or the Northern Lights, as it runs into the Earth and
is deflected by our magnetic field down into the skies near
the Poles.
What are the different stages of a total solar eclipse?
We have first contact, when the moon first starts to cross
the sun. That's when the partial eclipse starts, and that
happens for a while. And then you have second contact,
when the moon has finished covering the sun. That lasts for
only a few minutes. Third contact is when the first bit of
sunlight comes back, and fourth contact is when the eclipse
ends and the moon finishes crossing the sun.
Partial eclipses are visible before and after a total eclipse. Those who are near, but not within the path of totality, will only see a
partial eclipse. This 2013 partial eclipse was photographed from behind Cocoa Beach Pier in Cape Canaveral, Florida.
PHOTO
BY
ED
ROSACK
PHOTO
BY
KEVIN
SCHINDLER/LOWELL
OBSERVATORY
Scientists believe this petroglyph in Chaco Canyon may depict
an eclipse from July 11, 1097 A.D. The curlicues may represent
the sun's corona, and the dot to the upper left, Venus.
