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Eclipse day checklist and stages of the eclipse
to watch for |
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August 9, 2017 |
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| A series of
nine images were combined into a time
sequence of the total solar eclipse of
1999 August 11, from Lake Hazar, Turkey.
The corona has been computer enhanced to
show subtle details and prominences.
Copyright 1999 by Fred Espenak. |
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By Fred Espenak
EarthSky.org
So the big day – August 21 – is nearly here. Are
you all ready for the 2017 total eclipse of the
sun? It’s important to be prepared to take in
everything the eclipse has to offer.
You’ll be outside for hours and there are a
number of things you can do to make yourself
comfortable.
Eclipse Day Checklist
Basic Checklist
– Solar filters for your eyes (partial phases only; filters are removed
during totality; and bring extra filters to
share). For reputable dealers endorsed by the
American Astronomy Society,
click here.
– Straw hat, kitchen pasta colander, or cooking spoon with small holes to
project pinhole images of partially eclipsed sun
on a white piece of cardboard (see: Safe Solar
Eclipse Viewing)
– Suitable clothing and large brimmed hat (you will be outside in the sun
for several hours)
– Sunglasses (not for direct viewing of partial phases)
– Comfortable folding chairs or picnic blanket to sit on
– Sunscreen lotion
– Bug repellent
– Basic first aid kit
– Cooler filled with water and drinks
– Snacks, sandwiches, etc.
– Roll of toilet paper (for emergencies)
– A list of your intended activities during the eclipse
– Times of the eclipse contacts for your location, which can be found
using the
EclipseWise 2017 Google Eclipse Map
– Digital watch or cell phone with accurate time, set on the day of
eclipse
– A printed copy of this article to help you keep track of everything to
watch during the eclipse.
Equipment Checklist for Viewing and/or
Photographing Eclipse
– Binoculars and/or small telescope
– Solar filters for binoculars and/or telescope. For reputable dealers
endorsed by the American Astronomy Society,
click here
– Camera equipment and tripod
– Video camera and tripod
– Audio recorder for your comments and impressions or to capture
reactions of people or wildlife near you
– Audio recorder with prerecorded messages timed to cue you about what to
see next. There are some smart phone apps that
do this , such as the
Solar
Eclipse Timer or
EclipseDroid
– Extra batteries for all of the above
– Pencil and paper to record impressions or to sketch (also to take down
the names and addresses of fellow observers!)
The August 21 total eclipse will last several
hours. There will be many interesting things to
look for. Here is a handy checklist of must-see
events and effects, from eclipse gurus Fred
Espenak and Mark Littmann.
First Contact – The moon begins
to cover the western limb of the Sun. Remember
to use safe solar filters to watch the partial
phases of the eclipse.
Crescent Sun – Over a period of
about an hour, the moon obscures more and more
of the sun, as if eating away at a cookie. The
Sun appears as a narrower and narrower crescent.
Light and Color Changes – About
15 minutes before totality, when 80% of the sun
is covered, the light level begins to fall
noticeably — and with increasing rapidity. The
landscape takes on a metallic gray-blue hue.
Animal, Plant, and Human Behavior
– As the level of sunlight falls, animals may
become anxious or behave as if nightfall has
come. Some plants close up. Notice how the
people around you are affected.
Gathering Darkness on the Western
Horizon – About 5 minutes before
totality, the shadow cast by the Moon causes the
western horizon to darken as if a giant but
silent thunderstorm was approaching.
Temperature – As the sunlight
fades, the temperature may drop perceptibly.
Shadow Bands – A minute or two
before totality, ripples of light may flow
across the ground and walls as Earth’s turbulent
atmosphere refracts the last rays of sunlight.
Thin Crescent Sun – Only a
sliver of the S\sun remains, then thinner still
until . . .
Corona – Perhaps 15 seconds
before totality begins, as the sun becomes the
thinnest of crescents, the corona begins to
emerge.
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| As totality
ends, the sun begins to emerge from
behind the moon, producing the dazzling
diamond ring effect. Copyright 2016 by
Fred Espenak. |
Diamond Ring Effect – As the
corona emerges, the crescent sun has shrunk to a
short, hairline sliver. Together they form a
dazzlingly bright diamond ring. Then the
brilliant diamond fades into . . .
Baily’s Beads – About 3 seconds
before totality begins, the remaining crescent
of sunlight breaks into a string of beads along
the eastern edge of the moon. These are the last
few rays of sunlight passing through deep
valleys at the moon’s limb, creating the
momentary effect of jewels on a necklace.
Quickly, one by one, Baily’s Beads vanish behind
the advancing moon as totality begins.
Shadow Approaching – While all
this is happening, the moon’s dark shadow in the
west has been growing. Now it rushes forward and
envelops you.
Second Contact Totality Begins
– The sun’s disk (photosphere) is completely
covered by the moon. You can now remove your
solar filters and safely look directly at the
eclipse.
Prominences and the Chromosphere
– For a few seconds after totality begins, the
moon has not yet covered the lower atmosphere of
the sun and a thin strip of the vibrant red
chromosphere is visible at the sun’s eastern
limb. Stretching above the chromosphere and into
the corona are the vivid red prominences. A
similar effect occurs along the sun’s western
limb seconds before totality ends.
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| This image
of the solar corona is a High Dynamic
Range composite made from 22 separate
exposures. The original images were shot
by Espenak in Jalu, Libya during the
total solar eclipse of March 29, 2016.
The USPS used this image to create the
Total Eclipse of the Sun, Forever®
stamp. |
Planets and Stars Visible –
Venus and Mercury are often visible near the
eclipsed sun, and other bright planets and stars
may also be visible, depending on their
positions and the sun’s altitude above the
horizon.
Landscape Darkness and Horizon Color
– Each eclipse creates its own level of
darkness, depending mostly on the moon’s angular
size. At the far horizon all around you, beyond
the moon’s shadow, the sun is shining and the
sky has twilight orange and yellow colors.
Temperature – Is it cooler
still? A temperature drop of about 10°F (6°C) is
typical. The temperature continues to drop until
a few minutes after third contact.
Animal, Plant, and Human Reactions
– What animal noises can you hear? How are other
people reacting? How do you feel?
End of Totality Approaching –
The western edge of the moon begins to brighten
and vividly red prominences and the chromosphere
appear. Totality will end in seconds.
Third Contact – One bright
point of the sun’s photosphere appears along the
western edge of the moon. Totality is over. The
stages of the eclipse repeat themselves in the
reverse order.
Baily’s Beads – The point of
light becomes two, then several beads, which
fuse into a thin crescent with a dazzling bright
spot emerging, a farewell diamond ring.
Diamond Ring Effect and Corona
– As the diamond ring brightens, the corona
fades from view. Daylight returns.
Shadow Rushes Eastward
Shadow Bands Reappear – Shadow
Bands may be seen during the first 1-2 minutes
after totality ends.
Crescent Sun – Partial phases
occur in reverse order. Once again, you must use
your solar filter to watch all the partial
phases of the eclipse.
Recovery of Nature Partial Phase
– Flowers open up, animals return to normal
behavior, daylight regains its strength.
Fourth Contact – The moon no
longer covers any part of the sun. The eclipse
is over. |
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