So, what is it
like to experience a total solar eclipse? Why do some people travel all
across the world to see them? Actually, the best way to describe it is
to just use 3 words: Go see one. No description- written or verbal, no
photo, no painting, no video could EVER come close to describing the
majesty of a total eclipse of the sun. Although it's impossible to
convey the experience, you may be curious to know what happens during
one. So the following is my attempt to answer that.
Before I go on, let's assume a few things:
1. That
you're protecting your eyes using PROPER MATERIALS and PROPER METHODS
during ALL of the partial phases and when the sun is not eclipsed
(through a proper solar filter or looking at a projected image of the
sun). I'll post about this later.
2.
That you are looking directly at the eclipse during TOTALITY with NO
PROTECTION. It is safe to do that- but only during totality.
3. That you're going back to protecting your eyes after totality.
4. That you have a wide view down to the horizon in all or most directions (or as close as possible).
5. That the sky is clear or mostly so.
So,
it's eclipse day. You've arrived at your observing site, hopefully well
before the eclipse starts. You can spend that time taking advantage of
what the location has to offer: perhaps there are trails for walking, a
pool for swimming, or maybe you're at a festival with games and other
activities. Or perhaps you've brought something to do on your own- like a
book to read, or a ball to throw around. Of course, you could always
spend the time talking with others- certainly people you already know at
the observing site, and perhaps new-found friends- all there to share
in the grand celestial experience. Look around before the eclipse
begins. Sure, there may be lots of people at the observing site, but I
encourage you to look at the sky and other natural features of the area
at this point. Notice how you're about to experience an incredible,
dramatic natural event in just a few hours- yet there are NO signs from
nature indicating that it's going to happen! The sun is still shining
brightly, and animals are behaving as they normally do.
It's easy
to look up the time when the eclipse begins at your location. Sure
enough, right on time, (as you look through your protective filter or at
your projected image) you'll see that the sun appears to have a dent
taken out of it. That's not a dent, of course- that's the moon coming in
between the sun and the earth. As the minutes tick away, the moon
covers more of the sun. 10%, 20%, 30%- and so on. The progress seems
slow. It's likely that most people at your location are paying only some attention
to the eclipse: they're likely paying attention to the eclipse every
once in a while as they talk about- and do- other things. You may find yourself doing the same.
But at
some point, changes begin to happen. The light level begins to drop, the
temperature slowly begins to fall, and a strange calmness fills the
air. The changes will probably not all happen at the same time, but will
likely happen within a few minutes of each other. How much the sun is
covered when the changes start to happen can depend on various factors:
the atmospheric conditions, the experience of the observer, and how much
they're paying attention. The changes are subtle at first, but happen
with increasing intensity as time goes on. They are also different than
anything else you're used to experiencing in nature. The light level
drop is not like that of a sunset- the light is colored differently, and
you'll notice that the dimmest part of the sky is to the west. Shadows
become sharper instead of longer. The strange calmness that fills the
air is similar to what you might experience just before a severe
thunderstorm- but really, it's unlike anything you've ever felt before.
The sun has now been reduced to a crescent, and it is still shrinking.
60% covered... 70%.... 80%..... 90%..... The changes become more
noticeable.
The sun is now over 95% covered. Everyone is paying
full attention to the eclipse. There is an undeniable tension. You're
now less than 5 minutes away from totality. Look to the west. You may
notice the sky is dramatically dimmer in that direction. The shadow of the moon is approaching. You may start to understand
why people living many years ago- who would have not been able to
predict or understand what was happening- would have been very fearful.
96%....
4 minutes to go.... 97%.... 3 minutes..... 98%..... 2 minutes... The
solar crescent is shrinking. The excitement in the crowd builds. An
orange or yellow glow starts to be visible on the horizon. The changes
in the sky and across the landscape continue- at a faster and faster pace.
One minute to go.
The light level, which has been dropping slowly over the last few
minutes- is now dropping with each passing second. It's like a dimmer
switch is being turned on the world around you. Look to the west- you
see a curtain of darkness filling the sky in that direction. This is the
shadow of the moon racing toward you at thousands of miles per hour.
You feel completely unable to stop what's happening. You start to feel a
chill- literally and figuratively. People around you start to get very excited. It's an incredible experience.
You
take one last look through your proper solar filter- or at the
projected image of the sun- and see the thin solar crescent break up
into a string of beads. These are sunlight shining through valleys on
the moon while mountains in between them block the rest of the
sunlight. The beads last for a few seconds and then appear to get
swallowed by the moon until one remains. Then it disappears.
When
you look up, the sun- the very thing you need for light and life- is
gone. It's been replaced by a black hole in the sky. That's the moon-
coming exactly in between the sun and the earth. The moon appears to be
surrounded by a pearl- colored glow. This is the sun's corona- its outer
atmosphere. It's always there, of course, but it is hidden by the glare of the
sun's photosphere (its surface). The photosphere is the part that is
dangerous to look at- that's why you have to protect your eyes when any
part of it is visible. When the photosphere is completely blocked, it's
safe to look at the sun without protection and the corona is revealed in
all its glory.
"Glory" is a good word for the corona- people
have used the words "The Eye of God" to describe it. It is absolutely
SPECTACULAR. You'll see incredibly fine lines, loops and strands of
detail. Every one of those details is believed to be searingly hot (2
million degrees Celcius!) plasma tracing the lines of an enormous, chaotic
magnetic field that surrounds the sun. Some people report hints of
color in the corona, but the dominant color is white. The inner sections
of the corona show the most detail, while the outer corona stretches
into the sky like glowing wings. Look closely: you may notice reddish
flares of light reaching up into the inner corona. These are
prominences: giant explosions of hydrogen gas that burst into the lower
sections of the corona. Prominences do explode from the upper sections
of the solar surface and then rain back down again- but you don't notice
that motion during the few minutes of totality. You'll see them like a
freeze frame from a movie. Notice how the prominences have different
shapes: some are vertical, some are loops, some are arches- and others.
The
eclipsed sun is commanding your attention- but force your gaze away
from it for a few moments to look at some other amazing things. The sky
above you is a deep blue- similar to deep twilight. An orange (or
similar) colored glow is visible all the way around the horizon: a 360
degree sunset. A few of the brightest stars and planets may be visible.
It's like a scene from another world. But your eyes will be drawn-
again- to the beautiful corona.
You don't just see things during
totality- you'll feel things as well. Take a moment to notice them. The
temperature has dropped noticeably, and the strange calmness that
started as totality was approaching is now even more dramatic. You may
suddenly feel connected to the universe. It's an indescribable feeling.
Listen:
how are other people reacting? In many cases, people cheer the start of
totality, but as the eclipse progresses, the volume begins to decrease.
Everyone is looking around, transfixed by the experience.
Look
to the west again. Notice how the sky in that direction is becoming
brighter- the trailing edge of the shadow is headed your way. You take
one last look at the totally eclipsed sun. A reddish arc may appear on
the edge of the sun. This is the chromosphere- a thin layer of hydrogen
gas between the photosphere and the corona. A few seconds later, a
bright ray of sunlight pierces through a deep valley on the edge of the
moon- the "diamond ring" effect. Totality has ended- it is now time to
go back to protecting your eyes. Even though a partial eclipse is still
occurring as the moon moves away from the sun, most people don't pay
very much attention to that anyway- because the time after totality is
very anticlimactic! Instead, look around at the sky and the landscape.
Notice how fast it gets bright again! The sun has returned.
Don't be surprised if you're overwhelmed with emotion at this point.....
