Eclipse Day Checklist

So the BIG DAY has finally come. 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.

The checklist below will help you plan the perfect eclipse experience! Do your homework and the only other thing you’ll need is perfect weather!

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.

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.

Eclipse Day Checklist

    Basic Checklist

  • Solar filters for your eyes (partial phases only; filters are removed during totality; and bring extra filters to share)
  • 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 (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 Stages of a Total Solar Eclipse 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
  • 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*
  • 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)
  • * there are some smart phone apps that do this (e.g., Solar Eclipse Timer or EclipseDroid)

You may also be interested in reading:
Best Ways to View the Solar Eclipse
Safe Solar Eclipse Viewing
Stages of a Total Solar Eclipse
Experiencing Totality
Mr. Eclipse’s “How to Photograph a Solar Eclipse”
Eclipse Photographer’s Checklist

Fred Espenak ©2017


Solar Corona

A composite image of the total solar eclipse of 2006 March 29 was shot in Jalu, Libya. It was produced from 26 individual exposures obtained with two separate telescopes and combined with computer software to reveal subtle details in the corona. Copyright 2006 by Fred Espenak.

Eclipse Photographer’s Checklist

Earlier this year I presented a live webinar on Solar Eclipse Imaging. One of the handouts I prepared was a checklist to help photographers get ready for the Total Solar Eclipse of August 21, 2017. It listed many of the things you should do days or even weeks before the eclipse. That way, you’ll avoid many potential problems on the big day itself.

I’m reproducing it here to share with a bigger audience.

Photography Preparation Checklist (weeks before eclipse)

    Set up all your equipment for testing
  • Make checklist of all necessary equipment
    (camera, lens, solar filter, tripod, batteries, memory cards, cables, adapters, chargers, etc.)
  • Include any tools you will need
  • For video camera or computer, how long do batteries last?
  • If planning bursts with a DSLR, how may shots before buffer is full?

    For maximum stability, set tripod as low as practical
  • Do not extend center column
  • Hang weight (water bottle, bag of rocks, etc.) from center of tripod or tape to legs

    Practice aiming, framing and tracking the Sun with your camera
  • If using equatorial mount, learn how to polar align in daytime
    (use compass for NORTH & angle finder for LATITUDE)
  • If NOT using equatorial mount, practice tracking Sun
    (how long does it take the Sun to drift out of your field of view?)
  • Note: Sun moves across the sky at the rate of 1 diameter every 2 minutes

    Make sure you can remove the solar filter quickly without moving Sun out of field
  • Solar filter must be secure enough that wind won’t blow it off
  • Practice removing filter smoothly

    Prepare brief Eclipse Day notes
  • Use clipboard or index cards
  • List eclipse contact times for quick reference
  • Eclipse Day checklist
  • Any other notes you need at your fingertips

    Carefully pack up all your equipment
  • Set up all your equipment one last time
  • How long does it take to set up?
  • Consult checklist to make sure you have everything
  • Use poly tarp to lay out equipment before packing for eclipse
  • Don’t remove anything once you’ve packed

For more on the basics see Mr. Eclipse’s “How to Photograph a Solar Eclipse” and the Nikon Guide to Eclipse Photography. And check out Alan Dyer’s great ebook “How to Photograph the Solar Eclipse”.

Fred Espenak


As totality ends, the Sun begins to emerge from behind the Moon producing the dazzling diamond ring effect. Copyright 2005 by Fred Espenak.

Stages of a Total Eclipse

The August 21st total eclipse of the Sun lasts several hours. During this period, there and many interesting events and effects to be looking for. In the following excerpt from Totality – The Great America Eclipses of 2017 and 2024, this handy checklist will help you keep track of what and when to look for each of these must see events and effects. You might even want to print this page as a handy reference on eclipse day.

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.

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.

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 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.

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.

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.

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.

Corona Extent and Shape – The corona and prominences vary with each eclipse. How far (in solar diameters) does the corona extend? Is it round or is it broader at the Sun’s equator? Does it have the appearance of short bristles at the poles? Look for loops, arcs, and plumes that trace solar magnetic fields.

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.

diamond ring effect

As totality ends, the Sun begins to emerge from behind the Moon producing the dazzling diamond ring effect. Copyright 2016 by Fred Espenak.

Learn all about the Best Ways to View the Solar Eclipse and well as what it is like to Experience Totality.

You may also be interested in the 2017 Eclipse Stamp as well as a post about Total Solar Eclipses in the USA.

Totality – The Great America Eclipses of 2017 and 2024

Read much more in Totality – The Great America Eclipses of 2017 and 2024 by Mark Littmann and Fred Espenak.

Read much more in Totality – The Great America Eclipses of 2017 and 2024 by Mark Littmann and Fred Espenak.

About the Authors

Mark Littmann has written several popular books about astronomy. Planets Beyond: Discovering the Outer Solar System won the Science Writing Award of the American Institute of Physics. Planet Halley: Once in Lifetime (Donald K Yeomans, co-author) won the Elliott Montroll Special Award of the New York Academy of Sciences. Reviewers described The Heavens on Fire: The Great Leonid Meteor Storms as a “unique achievement,” “altogether satisfying,” and “a compelling read.”

Mark holds an endowed professorship, the Hill Chair of Excellence in Science Writing, at the University of Tennessee where he teaches three different courses in writing about science, technology, medicine, and the environment. He has helped lead expeditions to Canada, Hawaii, Bolivia, Aruba, and Turkey to observe total eclipses.

Fred Espenak is the most widely recognized name in solar eclipses. He is an astrophysicist emeritus at NASA’s Goddard Space Flight Center, where he founded and runs the NASA Eclipse Home Page, the most consulted website for eclipse information around the globe. His Five Millennium Canons of solar and lunar eclipses are seminal works for researchers, archaeologists, and historians.

Fred writes regularly on eclipses for Sky amp; Telescope and is probably the best known of all eclipse photographers. He leads expeditions for every total solar eclipse and has done so for more than 35 years. In 2003, the International Astronomical Union honored Espenak and his eclipse work by naming asteroid 14120 after him. The U. S. Postal Service recently used one of his photos on a postage stamp to commemorate the 2017 total eclipse of the Sun.

Fred Espenak


Best Ways to View the Solar Eclipse

Millions of people will soon travel to a narrow strip in America to witness a rare event: a total solar eclipse. On 21 August, many will look up to the sky to witness this phenomenon – will you be one of them? In the following shortened excerpt from Totality – The Great America Eclipses of 2017 and 2024, learn what types of eyewear you should be using to watch the Sun disappear, when you can do away with eye protection completely, and other ways to best view this event.

You would never think of staring at the Sun without eye protection on an ordinary day. You know the disk of the Sun is dazzlingly bright, enough to permanently damage your eyes. Likewise, any time the disk of the Sun is visible – throughout the partial phase of an eclipse – you need proper eye protection. Even when the Sun is nearing total eclipse, when only a thin crescent of the Sun remains, the 1% of the Sun’s surface still visible is about 10,000 times brighter than the Full Moon.

Once the Sun is entirely eclipsed, however, its bright surface is hidden from view and it is completely safe to look directly at the totally eclipsed Sun without any filters. In fact, it is one of the greatest sights in nature. Here are ways to observe the partial phases of a solar eclipse without damaging your eyes.

Solar Eclipse Glasses

The most convenient way to watch the partial phases of an eclipse is with solar eclipse glasses. These devices consist of solar filters mounted in cardboard frames that can be worn like a pair of eyeglasses. If you normally wear prescription eyeglasses, you place the eclipse glasses right in front of them.

When you are using a filter, do not stare for long periods at the Sun. Look through the filter briefly and then look away. In this way, a tiny hole that you miss will not cause you any harm. You know from your ignorant childhood days that it is possible to glance at the Sun and immediately look away without damaging your eyes. Just remember that your eyes can be damaged without you feeling any pain.

A Samburu man wears a pair of eclipses glasses in preparation for an annular eclipse in Kenya. These inexpensive glasses with cardboard frames have become very popular for safe eclipse viewing. [©2010 Fred Espenak]

Welder’s Goggles

Another safe filter for looking directly at the Sun is welder’s goggles (or the filters for welder’s goggles) with a shade of 13 or 14. They are relatively inexpensive and can be purchased from a welding supply company. The down side is that they cost more than eclipse glasses and give the Sun an unnatural green cast.

The Pinhole Projection Method

If you don’t have eclipse glasses or a welder’s filter, you can always make your own pinhole projector, which allows you to view a projected image of the Sun. There are fancy pinhole cameras you can make out of cardboard boxes, but a perfectly adequate (and portable) version can be made out of two thin but stiff pieces of white cardboard. Punch a small clean pinhole in one piece of cardboard and let the sunlight fall through that hole onto the second piece of cardboard, which serves as a screen, held behind it. An inverted image of the Sun is formed. To make the image larger, move the screen farther from the pinhole. To make the image brighter, move the screen closer to the pinhole. Do not make the pinhole wide or you will have only a shaft of sunlight rather than an image of the crescent Sun. Remember, a pinhole projector is used with your back to the Sun. The sunlight passes over your shoulder, through the pinhole, and forms an image on the cardboard screen behind it. Do not look through the pinhole at the Sun.

A pinhole projector can be used to safely watch the partial phases of a solar eclipse. It is easily fashioned from two stiff pieces of cardboard. One piece serves as the projection screen. Make a pinhole in the second piece and hold it between the Sun and the first piece. If the two cardboards are held 2 feet apart the projected image of the Sun will appear about 1/4-inch in size. [Drawing by Fred Espenak]

Even a simple pasta colander can be used to project dozens of images of the eclipsed Sun onto a piece of white cardboard. [©2000 Fred Espenak]

Solar Filters for Cameras, Binoculars, and Telescopes

Many telescope companies provide special filters that are safe for viewing the Sun. Black polymer filters are economical but some observers prefer the more expensive metal-coated glass filters because they produce sharper images under high magnification.

Caution: Do not confuse these filters, which are designed to fit over the front of a camera lens or the aperture of a telescope, with a so-called solar eyepiece for a telescope. Solar eyepieces are still sometimes sold with small amateur telescopes. They are not safe because they absorb heat and tend to crack, allowing the sunlight concentrated by the telescope’s full aperture to enter your eye.

Eye Suicide

Do not use standard or polaroid sunglasses to observe the partial phases of an eclipse. They are not solar filters. Standard and polaroid sunglasses cut down on glare and may afford some eye relief if you are outside on a bright day, but you would never think of using them to stare at the Sun. So you must not use sunglasses, even crossed polaroids, to look directly at the Sun during the partial phases of an eclipse.

Do not use smoked glass, medical x-ray film with images on them, photographic neutral-density filters, and polarizing filters. All these “filters” offer utterly inadequate eye protection for observing the Sun.

Observing with Binoculars

Binoculars are excellent for observing total eclipses. Any size will do. Astronomy writer George Lovi’s favorite instrument for observing eclipses was 7 x 50 binoculars – magnification of seven times with 50-millimeter (2-inch) objective lenses. “Even the best photographs do not do justice to the detail and color of the Sun in eclipse,” Lovi said, “especially the very fine structure of the corona, with its exceedingly delicate contrasts that no camera can capture the way the eye can.” He felt that the people who did the best job of capturing the true appearance of the eclipsed Sun were the 19th century artists who photographed totality with their eyes and minds and developed their memories with paints on canvas.

For people who plan to use binoculars on an eclipse, Lovi cautioned common sense. Totality can and should be observed without a filter, whether with the eyes alone or with binoculars or telescopes. But the partial phases of the eclipse, right up through the diamond ring effect, must be observed with filters over the objective (front) lenses of the binoculars. Only when the diamond ring has faded is it safe to remove the filter. And it is crucial to return to filtered viewing as totality is ending and the western edge of the Moon’s silhouette brightens with the appearance of the second diamond ring. After all, binoculars are really two small telescopes mounted side by side. If observing a partially eclipsed Sun without a filter is quickly damaging to the unaided eyes, it is far quicker and even more damaging to look at even a sliver of the uneclipsed Sun with binoculars that lack a filter.

Binoculars can be used to safely project a magnified image of the Sun onto a piece of white cardboard. Never look at the Sun directly through binoculars unless they are equipped with solar filters. [©2000 Fred Espenak]

Totality – The Great America Eclipses of 2017 and 2024

Read much more in Totality – The Great America Eclipses of 2017 and 2024 by Mark Littmann and Fred Espenak.

Read much more in Totality – The Great America Eclipses of 2017 and 2024 by Mark Littmann and Fred Espenak.

About the Authors

Mark Littmann has written several popular books about astronomy. Planets Beyond: Discovering the Outer Solar System won the Science Writing Award of the American Institute of Physics. Planet Halley: Once in Lifetime (Donald K Yeomans, co-author) won the Elliott Montroll Special Award of the New York Academy of Sciences. Reviewers described The Heavens on Fire: The Great Leonid Meteor Storms as a “unique achievement,” “altogether satisfying,” and “a compelling read.”

Mark holds an endowed professorship, the Hill Chair of Excellence in Science Writing, at the University of Tennessee where he teaches three different courses in writing about science, technology, medicine, and the environment. He has helped lead expeditions to Canada, Hawaii, Bolivia, Aruba, and Turkey to observe total eclipses.

Fred Espenak is the most widely recognized name in solar eclipses. He is an astrophysicist emeritus at NASA’s Goddard Space Flight Center, where he founded and runs the NASA Eclipse Home Page, the most consulted website for eclipse information around the globe. His Five Millennium Canons of solar and lunar eclipses are seminal works for researchers, archaeologists, and historians.

Fred writes regularly on eclipses for Sky amp; Telescope and is probably the best known of all eclipse photographers. He leads expeditions for every total solar eclipse and has done so for more than 35 years. In 2003, the International Astronomical Union honored Espenak and his eclipse work by naming asteroid 14120 after him. The U. S. Postal Service recently used one of his photos on a postage stamp to commemorate the 2017 total eclipse of the Sun.

Fred Espenak


Experiencing Totality

The great American total eclipse of the Sun is now just three months away. Those of us who have witnessed totality (that brief period when the the Sun’s brilliant disk is completely hidden revealing its glorious corona) realize how monumentally difficult it is to convey that experience to others. Words often fail when trying to explain the kaleidoscope of sights, sounds, feelings and emotions that consume us during this other-worldly event.

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.

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.

The best description I’ve ever read of the “Totality experience” was written over a century ago by Mabel Loomis Todd (“Total Eclipses of the Sun”, 1894). Todd was an American writer and editor who traveled to a number of total eclipses with her husband astronomer David Peck Todd during the late 19th Century.

Her description is not only expressive and passionate, but it accurately captures the variety and sequence of events in a most compelling way.

    “As the dark body of the Moon gradually steals its silent way across the brilliant Sun, little effect is at first noticed. The light hardly diminishes, apparently, and birds and animals detect no change.”

    During the partial phase a curious appearance may be noticed under any shade tree. Ordinarily, without an eclipse, the sunlight filters through the leaves in a series of tiny, overlapping disks on the ground, each of which is an image of the Sun. But when the partial phase of an eclipse is well advanced, these sunny spots become crescent in form, images of the now narrowing Sun.”

    The gaps between the leaves on a tree act like a series pinhole cameras that each project an image of the eclipse Sun on the ground below.

    The gaps between the leaves on a tree act like a series pinhole cameras that each project an image of the eclipse Sun on the ground below.

    “As the entire duration of an eclipse, partial phases and all, embraces two or three hours, often for an hour after ‘first contact’ insects still chirp in the grass, birds sing, and animals quietly continue their grazing. But a sense of uneasiness seems gradually to steal over all life. Cows and horses feed intermittently, bird songs diminish, grasshoppers fall quiet, and a suggestion of chill crosses the air. Darker and darker grows the landscape.

    As much as five minutes before total obscurity it may be possible to detect strange wavering lines of light and shade dance across the landscape – the ‘shadow bands’ as they are called – a curious and beautiful effect (related to the same atmospheric phenomenon that causes stars to twinkle).

    Shadow Bands

    Shadow bands are seen to ripple across a house in Sicily during a total eclipse in 1870.

    “Then, with frightful velocity, the actual shadow of the Moon is often seen approaching, a tangible darkness advancing almost like a wall, swift as imagination, silent as doom. The immensity of nature never comes quite so near as then, and strong must be the nerves not to quiver as this blue-black shadow rushes upon the spectator with incredible speed. A vast, palpable presence seems to overwhelm the world. The blue sky changes to gray or dull purple, speedily becoming more dusky, and a death-like trance seizes upon everything earthly. Birds with terrified cries, fly bewildered for a moment, and then silently seek their night quarters. Bats emerge stealthily. Sensitive flowers, the scarlet pimpernel, the African mimosa, close their delicate petals, and a sense of hushed expectancy deepens with the darkness.

    An assembled crowd is awed into silence almost invariably. Trivial chatter and senseless joking cease. Sometimes the shadow engulfs the observer smoothly, sometimes apparently with jerks; but all the world might well be dead and cold and turned to ashes. Often the very air seems to hold its breath for sympathy; at other times a lull suddenly awakens into a strange wind, blowing with unnatural effect.

    Then out upon the darkness, gruesome but sublime, flashes the glory of the incomparable corona, a silvery, soft, unearthly light, with radiant streamers, stretching at times millions of uncomprehended miles into space, while the rosy, flame-like prominences skirt the black rim of the moon in ethereal splendor. It becomes curiously cold, dew frequently forms, and the chill is perhaps mental as well as physical.”

Solar Corona

A composite image of the total solar eclipse of 2006 March 29 was shot in Jalu, Libya. It was produced from 26 individual exposures obtained with two separate telescopes and combined with computer software to reveal subtle details in the corona. Copyright 2006 by Fred Espenak.

Allow me to interject here for a moment. Totality never lasts more than 7 and 1/2 minutes. But this is exceedingly rare and will not happen again until 2186. It is far more common for totality to last a mere 2 or 3 minutes, and this is the case for the 2017 eclipse. Although the corona appears static (no visible motion) during this brief interval, it is never-the-less mesmerizing in its delicate gossamer beauty. This million-degree plasma is electrically charged and twisted by the intense magnetic fields of the Sun into a complex array of streamers, plumes, brushes, and loops. All of this surrounds the jet-black disk of the Moon appearing as an eerie hole in the heavens.

Many inexperienced writers often say that “day turns to night”, but the darkness of totality more closely resembles evening twilight when the first stars become visible. The colors of sunset/sunrise ring the horizon as you look out the edge of the lunar shadow into locations still bathed in sunlight. And the brightest planets are visible to the naked eye. In the case of 2017, Venus and Jupiter will easily be seen.

Totality

The eerie twilight of totality is seen against a backdrop of thorn acacia trees in this wide-angle photograph shot during the total solar eclipse of 2001 June 21 from Chisamba, Zambia. Copyright 2001 by Fred Espenak.

Although these sights are all impressive, the eye is invariably drawn back to the corona and its apparition-like appearance and exquisite detail.

Todd’s description of the end of totality continues:

    “Suddenly, instantaneously as a lightning flash, an arrow of actual sunlight strikes the landscape, and Earth comes to life again, while the corona and prominences melt into the returning brilliance, and occasionally the receding lunar shadow is glimpsed as it flies away with the tremendous speed of its approach.

    The great opportunity has come and gone, and happy is the astronomer who has kept the poetry of his nature in such abeyance that the merely accurate and scientific work has been accomplished; but in executing his prescribed program, the professional observer must exercise vast self-control.

    Professor Langley says of this superb sight: “The spectacle is one of which, though the man of science may prosaically state the facts, perhaps only the poet could render the impression.”

    I doubt if the effect of witnessing a total eclipse ever quite passes away. The impression is singularly vivid and quieting for days, and can never be wholly lost. A startling nearness to the gigantic forces of nature and their inconceivable operation seems to have been established. Personalities and towns and cities, and hates and jealousies, and even mundane hopes, grow very small and very far away.”

diamond ring effect

As totality ends, the Sun begins to emerge from behind the Moon producing the dazzling diamond ring effect. Copyright 2016 by Fred Espenak.

Totality – The Great America Eclipses of 2017 and 2024, my newly published book with Mark Littmann has a unique feature called “Moments of Totality.” These are personal anecdotes and stories shared by people who have witness totality themselves. A separate “Moment of Totality” appears after each chapter in the book adding many different voices to this topic.

Please share this post with anyone who is still unsure about whether a trip to the 2017 path of totality is worth the effort.

Fred Espenak


2017 Eclipse Stamp

While I wouldn’t call myself a philatelist, I’ve always been interested in collecting eclipse stamps since my early days as an eclipse chaser. On an eclipse expedition to Mauritania, Africa in 1973, I eagerly sought out a set of three Mauritanian stamps to commemorate that eclipse.

Eclipse stamps have been wonderful momentos and reminders of eclipse trips over the years. Indonesia (1983), the Philippines (1988), Mexico (1991), and Aruba (1998) are a few of the countries that have commemorated solar eclipses with postage stamps.

When I launched the MrEclipse.com website in 1999, one of the first features was a series of pages devoted to eclipse stamps. Some of my fellow eclipse chasers have generously shared scans of stamps missing from my collection.

Postage stamp from Hungary uses Espenak's eclipse bulletin map to commemorate the 1999 total solar eclipse through Europe.

Postage stamp from Hungary uses Espenak’s eclipse bulletin map to commemorate the 1999 total solar eclipse through Europe.

On some eclipse trips, I’ve been astonished to discover countries “borrowing” my maps from the NASA eclipse bulletins and featuring them on commemorative stamps. This first happened in Mongolia in 1997 and again in Hungary in 1999. While flattering, I was puzzled why the postal services in these countries never bothered to even contact me about this. Of course, they had every right to use the maps since they were in the public domain, but still, it would have been nice to be notified.

But in Libya, I was startled to find one of my eclipse photos staring back at me in a set of Libyan stamps commemorating the total solar eclipse of 2006. I guess I shouldn’t have been too surprised since I also saw vendors selling t-shirts featuring boot-legged copies of my eclipse photos presumably downloaded from MrEclipse.com.

Libya “borrowed” (without permission) one of Espenak’s eclipse photos (on the right) and reproduced it on a stamp (on the left) commemorating the total solar eclipse of March 29, 2006.

Libya “borrowed” (without permission) one of Espenak’s eclipse photos (on the right) and reproduced it on a stamp (on the left) commemorating the total solar eclipse of March 29, 2006.

My wife Pat and I took it in good humor and even framed a set of the Libyan eclipse stamps for our home in Arizona along with a print of the “pinched” eclipse photo for comparison.

With the upcoming total solar eclipse through the USA in 2017, I had heard many eclipse chasers contend that such a momentous occasion deserves commemoration with a postage stamp. While I heartily agreed with them, I had no idea how to petition the U. S. Postal Service and convince them of the merit of this idea. Nor was I even inclined to do so since I was busy writing several books about the 2017 eclipse.

I was surprised when a representative of the U. S. Postal Service contacted me looking for photographs to consider for just such a commemorative stamp. I quickly submitted a selection of images and image sequences for consideration.

At first, I was simply a consultant on the project with no promise of whether any of my images would be used or even if a stamp would ever be produced. All the while I was cautioned that all stamp projects are strictly confidential and tentative until approved by the Postmaster General. Months went by and I was asked to help with a press release and explanatory material that would accompany the introduction of the eclipse stamp.

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, 2006. The USPS used this image to create the <em>Total Eclipse of the Sun, Forever® stamp</em>.

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, 2006. The USPS used this image to create the Total Eclipse of the Sun, Forever® stamp.

Eventually, the artist in charge of the stamp design was considering some of my 2006 eclipse photos. Yes! Maybe? Still no promises. And I was still required to keep the project to myself.

Months passed and I was asked to verify the accuracy of an eclipse path map containing eclipse times for various cities. Finally, I was asked for a high resolution file of one of my 2006 eclipse photos. The Postal Service was exploring several different images for possible use on the stamp. They also wanted a corresponding Full Moon image to place over the eclipse which would become visible through the use of thermochromic ink. Well this was something I’d never heard of before! I searched though my collection of astrophotos for an appropriate Full Moon image as requested.

Just after the New Year, the news came that my images would definitely appear on the new stamp. I was delighted but still forbidden to share this information. I had to wait until the USPS issued a press release officially announcing the stamp. January, February and March rolled by as I got busy giving lectures and interviews about the Great American Eclipse.

On April 24, I reviewed the final version of the press release for the stamp. More corrections and tweaks were made. The official announcement finally happened on April 27.

The <em>Total Eclipse of the Sun, Forever® stamp</em> transforms into an image of the Moon from the heat of a finger. Espenak shot the eclipse photo from Jalu, Libya in 2006, while the Full Moon image was made from his observatory in Portal, Arizona in 2010. The stamp commemorates the total solar eclipse of August 21, 2017 that crosses the USA.

The Total Eclipse of the Sun, Forever® stamp transforms into an image of the Moon from the heat of a finger. Espenak shot the eclipse photo from Jalu, Libya in 2006, while the Full Moon image was made from his observatory in Portal, Arizona in 2010. The stamp commemorates the total solar eclipse of August 21, 2017 that crosses the USA.

“The Postal Service will soon release a first-of-its-kind stamp that changes when you touch it. The Total Eclipse of the Sun, Forever® stamp, which commemorates the August 21 eclipse, transforms into an image of the Moon from the heat of a finger.” (See: USPS Press Release)

The First-Day-of-Issue ceremony will take place on the summer solstice, June 20, 1:30 p.m. MT at the Art Museum of the University of Wyoming (UW) in Laramie. Pat and I are both planning to attend.

I’m honored to have my images on this unique stamp. But more importantly, the stamp will spread the news about America’s Great Eclipse to many more people than I could ever reach. A total eclipse of the Sun is simply the most beautiful, stunning and awe-inspiring astronomical event you can see with the naked eye. But you’ve got to be in the 70-mile-wide path of totality that runs across the nation from Oregon to South Carolina. So where will you be on August 21, 2017?

Fred Espenak



Moon in 2017

Moon Phases Mosaic

A mosaic made from 9 individual photos of the Moon captures its phases over one synodic month. For complete details about this image, see Moon Phases Mosaic. The individual images included in this composite can be found in the Moon Phases Gallery. For more composites, see Moon Phases Mosaics. Photo copyright 2012 by Fred Espenak.

We tend to take the Moon for granted but it shares a unique history with Earth. Shortly after its formation 4.5 billion years ago, “proto-Earth” collided with a Mars-sized object called Theia. Much of “proto-Earth” and Theia merged to become our Earth, but the impact also ejected a large amount of material into space. Some of it coalesced to become the Moon (see: Giant Impact Hypothesis).

The Moon’s orbit stabilizes the axial tilt of Earth, preventing it from undergoing chaotic variations that would lead to catastrophic changes in climate. And the daily rise and fall of the Moon-induced tides has left an indelible imprint on Earth. Some scientists even argue whether life on Earth would be possible without the influence of the Moon (see: Without the Moon, Would There Be Life on Earth?).

With this big picture in mind, we gain a new appreciation for the Moon as we watch its phases, cycles, and motions during 2017.

As the Moon orbits Earth, its changing geometry with respect to the Sun produces the Moon’s characteristic phases (New Moon, First Quarter, Full Moon and Last Quarter). One orbit of the Moon relative to the Sun (the synodic month) has a mean duration of 29.5306 days (29 days 12 hours 44 minutes).

                   Moon Phases for 2017 (GMT)

   New Moon      First Quarter      Full Moon       Last Quarter
-------------    -------------    -------------    -------------   
                 Jan  5  19:47    Jan 12  11:34    Jan 19  22:14    
Jan 28  00:07    Feb  4  04:19    Feb 11  00:33n   Feb 18  19:33    
Feb 26  14:58A   Mar  5  11:32    Mar 12  14:54    Mar 20  15:58    
Mar 28  02:57    Apr  3  18:39    Apr 11  06:08    Apr 19  09:57    
Apr 26  12:16    May  3  02:47    May 10  21:43    May 19  00:33    
May 25  19:44    Jun  1  12:42    Jun  9  13:10    Jun 17  11:33    
Jun 24  02:31    Jul  1  00:51    Jul  9  04:07    Jul 16  19:26    
Jul 23  09:46    Jul 30  15:23    Aug  7  18:11p   Aug 15  01:15    
Aug 21  18:30T   Aug 29  08:13    Sep  6  07:03    Sep 13  06:25    
Sep 20  05:30    Sep 28  02:54    Oct  5  18:40    Oct 12  12:25    
Oct 19  19:12    Oct 27  22:22    Nov  4  05:23    Nov 10  20:37    
Nov 18  11:42    Nov 26  17:03    Dec  3  15:47    Dec 10  07:51    
Dec 18  06:31    Dec 26  09:20                                        

The table above lists the date and time of the Moon’s phases throughout 2017. The time of each phase is given in Greenwich Mean Time or GMT (a.k.a. Universal Time or UT). A table of the Moon’s phases covering 100 years on AstroPixels.com can be found at Moon’s Phases – 21st Century (GMT). Similar 100-year tables for other time zones include Eastern Standard Time (EST), Central Standard Time (CST), Mountain Standard Time (MST), and Pacific Standard Time (PST). To convert GMT to other time zones, visit Time Zones.

Moonrise on 2015 January 05 from Portal, AZ. Copyright 2015 by Fred Espenak.

What surprises many people is that the length of the synodic month (period from New Moon to New Moon) can vary by more than 6 hours from its mean value of 29.5306 days (29 days 12 hours 44 minutes). The table below gives the date of New Moon, the length of the synodic month, and the difference from the synodic month’s mean value for every synodic month in 2017. For instance, the fifth synodic month of 2017 (beginning May 25) is 5 hours 58 minutes shorter than the mean while the twelfth synodic month (beginning Dec 18) is 7 hours 3 minutes longer than the mean.

                  Synodic Months for 2017 

   Date/Time of          Length of      Difference from
  New Moon (GMT)       Synodic Month      Mean Month 
------------------     -------------     -----------
2017 Jan 28  00:07      29d 14h 51m       +02h 07m
2017 Feb 26  14:58      29d 11h 59m       -00h 45m
2017 Mar 28  02:57      29d 09h 19m       -03h 25m
2017 Apr 26  12:16      29d 07h 28m       -05h 16m
2017 May 25  19:44      29d 06h 46m       -05h 58m   shortest
2017 Jun 24  02:31      29d 07h 15m       -05h 29m
2017 Jul 23  09:46      29d 08h 45m       -03h 59m
2017 Aug 21  18:30      29d 11h 00m       -01h 44m
2017 Sep 20  05:30      29d 13h 42m       +00h 58m
2017 Oct 19  19:12      29d 16h 30m       +03h 46m
2017 Nov 18  11:42      29d 18h 48m       +06h 04m
2017 Dec 18  06:30      29d 19h 47m       +07h 03m   longest

What causes these variations? The explanation involves the Moon’s elliptical orbit and its orientation with respect to the Sun during any given month. If New Moon occurs when the Moon is nearest to Earth (perigee), then the synodic month is shorter than normal. On the other hand, if New Moon occurs when the Moon is farthest from Earth (apogee), then the synodic month is longer than normal. Furthermore, the orientation of the Moon’s ellipse-shaped orbit slowly rotates in space with a period of about 18 years. A more detailed discussion on this topic can be found at Moon’s Orbit and the Synodic Month (EclipseWise.com). You can also find the duration of every synodic month this century at Length of the Synodic Month: 2001 to 2100 (AstroPixels.com).

The time it takes for the Moon to orbit once with respect to its perigee is known as the anomalistic month. Its average length is 27.55455 days (27 days 13 hours 19 minutes), which is nearly 2 days less than the synodic month. The actual length can vary by several days due to the gravitaional effects of the Sun on the Moon’s elliptical orbit. The table below gives the date and time of every perigee and apogee of the Moon during 2017. The Moon’s distance (in kilometers) is also given. The ‘m’ or ‘M’ appearing next to a date indicates the minimum or maximum distance, respectively, for the year. A table listing details of every perigee and apogee this century can be found at Perigee and Apogee: 2001 to 2100 (AstroPixels.com)

                  Perigee & Apogee for 2017 
                  
Date/Time of   Distance       Date/Time of   Distance
Perigee (GMT)    (km)         Apogee (GMT)     (km)
-------------   ------        -------------   ------
Jan 10  06:07   363242        Jan 22  00:14   404913       
Feb 06  13:59   368817        Feb 18  21:14   404376       
Mar 03  07:24   369065        Mar 18  17:25   404651       
Mar 30  12:39   363855        Apr 15  10:05   405478       
Apr 27  16:18   359325        May 12  19:51   406212       
May 26  01:23   357210 m      Jun 08  22:21   406402       
Jun 23  10:49   357938        Jul 06  04:27   405934       
Jul 21  17:09   361238        Aug 02  17:55   405026       
Aug 18  13:14   366129        Aug 30  11:25   404307 m     
Sep 13  16:04   369856 M      Sep 27  06:49   404342       
Oct 09  05:51   366858        Oct 25  02:25   405151       
Nov 06  00:09   361438        Nov 21  18:52   406132       
Dec 04  08:42   357496        Dec 19  01:27   406605 M     

Because the Moon orbits Earth in about 29.5 days with respect to the Sun, its daily motion against the background stars and constellations is quite rapid, averaging 12.2° per day. A table giving the Moon’s daily celestial coordinates throughout the year can be found at Moon Ephemeris for 2017 (AstroPixels.com). This table lists many other details about the Moon including its daily distance, apparent size, libration, phase age (days since New Moon) and the phase illumination fraction.

The most recent Perigean Full Moon (Full Moon near Perigee or closest point to Earth) took place on Dec. 13, 2016. The media loves to call this a “Super Moon” but I prefer to call it the less sensational “Perigean Full Moon” or “Full Moon near perigee”. Whatever you call it, it’s a chance to take a moment and marvel at our beautiful natural satellite. The photo below was taken from my driveway in Portal, AZ as the Moon rose above the Peloncillo Mountains of New Mexico. I was hoping for a completely clear sky but the clouds actually added an appealing element to the scene. Copyright 2016 by Fred Espenak.

When a Full Moon occurs within 90% of the Moon’s closest approach to Earth in a given orbit, it is called a Perigean Full Moon or more commonly a Super Moon. The Full Moon then appears especially big and bright because it subtends its largest apparent diameter as seen from Earth. The table below lists the Perigean Full Moons (Super Moons) occurring in 2017.

  Perigean Full Moons (Super Moons) for 2017

   Full Moon     Distance  Diameter  Relative
    (GMT)          (km)    (arc-min) Distance

Jan 12  11:34     366880     32.57    0.913
Nov 04  05:23     364004     32.83    0.941
Dec 03  15:47     357987     33.38    0.990   closest

The Relative Distance listed in the Super Moon table expresses the Moon’s distance as a fraction between apogee (0.0) and perigee (1.0). For more information on Super Moons and a complete list of them for this century, see Full Moon at Perigee (Super Moon): 2001 to 2100 (AstroPixels.com).

Besides its obvious phases, the Moon also undergoes some additional extremes in its orbit including: Perigee and Apogee, Ascending/Descending Nodes, and Lunar Standstills. Each of these AstroPixels links covers lunar phenomena for the entire 21st Century.

Moon Phases Mosaic

As the Moon orbits Earth, its changing geometry with respect to the Sun produces the characteristic phases. This composite image is a mosaic made from 25 individual photos of the Moon and illustrates its phases over one synodic month. For complete details about this image, see Moon Phases Mosaic. The individual images included in this composite can be found in the Moon Phases Gallery. For more composites, see Moon Phases Mosaics. Photo copyright 2012 by Fred Espenak.

One of the first projects I tackled upon completing Bifrost Observatory in 2010 was to photograph the Moon’s phases every day for a complete month. Of course, the weather doesn’t always cooperate (even from sunny Arizona) so it actually took several months to complete the project. You can see the results at the Moon Phases Gallery. Clicking on any of the thumbnail pictures will give you an enlarged image with complete technical details. You can also visit Moon Phases Mosaics to see composites showing the Moon’s phases over a complete synodic month.

The NASA/Goddard Scientific Visualization Studio has used image data from the Lunar Reconnaissance Orbiter (LRO) mission to create clever animations of the Moon’s ever changing phases and librations in 2017. The example below illustrates the Moon’s phase and libration at hourly intervals throughout 2017, as viewed from the northern hemisphere. Each frame represents one hour.

And not to be accused of northern hemisphere chauvinism, here is a version as seen from the southern hemisphere.

Besides presenting the Moon’s phase and apparent size, these videos show the Moon’s orbital position, sub-Earth and subsolar points, distance from the Earth at true scale, and labels of craters near the terminator. As the Moon orbits Earth, it appears to wobble and tip on its axis. This motion is called libration and it allows us to see about 59% of the Moon’s surface (see Libration (EarthSky)). The major cause of libration is due to our changing line of sight because of the Moon’s elliptical orbit.

Ernie Wright of the NASA Scientific Visualization Studio has also used LRO data to create a web tool called Dial-A-Moon. Enter the month, day and hour and Dial-A-Moon will generate a visualization of the Moon showing the correct phase and libration for that instant during 2017 (see Moon Phase and Libration, 2017).

Finally, what discussion of the Moon would be complete without mentioning eclipses in 2017? There are two eclipses of the Moon. The first is a deep penumbral eclipse on February 11, which is visible from both the Eastern and Western Hemispheres. Penumbral eclipses are rather subtle events and often transpire without any notice (see: Visual Appearance of Penumbral Lunar Eclipses). The second lunar eclipse is partial on August 7 and is visible from the Eastern Hemisphere.

There are also two solar eclipses in 2017. The first is an annular eclipse on February 26. The annular phase of the eclipse is visible from Chile, Argentina, the south Atlantic, Angola, Democratic Republic of the Congo, and Zambia.

The total solar eclipse of August 21, 2017 is the first total eclipse visible from the continental USA since 1979. For more information see the special EclipseWise web page on the 2017 eclipse.

The total solar eclipse of August 21, 2017 is the first total eclipse visible from the continental USA since 1979. For more information see the special EclipseWise web page on the 2017 eclipse.

The second solar eclipse of the year is the long awaited Great American Total Solar Eclipse on August 21. This is the first total solar eclipse visible from the continental USA in 38 years. For complete details on this highly anticipated event, see: 2017 Total Solar Eclipse (EclipseWise.com).

For more details on all these events, see Eclipses During 2017 (EclipseWise.com).

Moonset: Crescent Moon & Earthshine from Portal, AZ. Copyright 2015 by Fred Espenak.

For those who are new to Moon watching, many are surprised that the entire Moon can often be seen during the crescent phase. The pale glow illuminating the unlit part of a crescent Moon is light reflected from Earth and it’s called earthshine. The time-lapse movie above captures earthshine during moonset back one evening in May 2015. Read more about earthshine in this Earth&Sky article.

Watching the Moon’s phases wax and wane as well as the occasional lunar eclipse can best be enjoyed with the naked eye and binoculars. And you don’t even need a dark sky since the Moon is easily visible from the heart of brightly lit cities.

The Moon phases and lunar phenomena discussed here were all generated with computer programs I’ve written (THINK Pascal and FORTRAN 90 running on a Macintosh G4 and MacBook Pro) using Astronomical Algorithms (Jean Meeus).

Fred Espenak


Total Solar Eclipses in the USA

Eleven images capture various phases of the 2001 total eclipse from start to finish. Courtesy of "MrEclipse.com".

Eleven images capture various phases of the 2001 total eclipse from start to finish. Courtesy of “MrEclipse.com“.

With interest rapidly building for the upcoming total solar eclipse in the USA on 2017 August 21, I became curious about the rarity of total eclipses in America. The very first total eclipse I witnessed was on 1970 March 7. The path of totality crossed the southeastern USA and included portions of Florida, Georgia, North and South Carolina, Virginia and Nantucket.

Another total eclipse was visible in the USA from the Pacific Northwest (Oregon, Washington, Idaho, Montana and North Dakota) on 1979 February 26. Although a total eclipse was seen on the Big Island of Hawaii on 1991 July 11, no other total eclipse is visible from the lower 48 states of the USA between 1979 and 2017 – a lapse of over 38 years!

Map 1 shows the path of all total (blue) and annular (yellow) eclipses through the continental USA from 1951 through 2000. Courtesy of "Atlas of Central Solar Eclipses in the USA".

Map 1 shows the path of all total (blue) and annular (yellow) eclipses through the continental USA from 1951 through 2000. Courtesy of “Atlas of Central Solar Eclipses in the USA“.

Map 1 shows the path of all total (and annular) eclipses through the continental USA during the last 50 years of the 20th century. Besides the 1970 and 1979 eclipses, the only other USA total eclipses during this period were on 1963 July 20 (Alaska and Maine) and 1954 June 30 (Nebraska, South Dakota, Iowa, Minnesota and Michigan).

Map 2 shows all total (and annular) eclipses through the continental USA during the first 50 years of the 21st century. Looking beyond 2017, the next total eclipse through the USA is on 2024 April 8 and crosses 13 states (Texas, Oklahoma, Arkansas, Missouri, Illinois, Kentucky, Indiana, Ohio, Pennsylvania, New York, Vermont, New Hampshire and Maine). The total eclipse of 2044 August 23 crosses Montana and North Dakota. It is followed one year later by the total eclipse of 2045 August 12, which also crosses 13 states (California, Nevada, Utah, Colorado, Kansas, Oklahoma, Texas, Arkansas, Mississippi, Louisiana, Alabama, Georgia, and Florida). Although a total eclipse occurs on 2033 March 30, it is only visible from northern Alaska.

Map 2 shows the path of all total (blue) and annular (yellow) eclipses through the continental USA from 2001 through 2050. Courtesy of "Atlas of Central Solar Eclipses in the USA".

Map 2 shows the path of all total (blue) and annular (yellow) eclipses through the continental USA from 2001 through 2050. Courtesy of “Atlas of Central Solar Eclipses in the USA“.

If we only count total eclipses visible from the lower 48 states, we have 4 eclipses from 1951 to 2000, and 4 more from 2001 to 2050. Put another way, there are 8 chances to view a total eclipse from the USA in the period spanning just over a single lifetime. And that’s not even considering the fact that cloudy weather will likely hide half of them from view! Rare events indeed! And one more argument not to miss the Great American Total Eclipse of 2017.

But what if we look many centuries into the future? Does every one of the lower 48 states get a total eclipse in the next 1000 years? Map 3 shows the result of plotting the path of every total eclipse from 2001 through 3000. The country is almost completely covered by eclipse paths. Nevertheless, there are few unlucky locations that do not get a total eclipse over the next 1,000 years. Two examples include western Texas and southern New Mexico. Fear not because they will all eventually fall within the Moon’s shadow sometime. You just have to wait long enough.

Map 3 shows the path of all total eclipses through the continental USA for the next 1000 years (from 2001 through 3000). Courtesy of "Atlas of Central Solar Eclipses in the USA".

Map 3 shows the path of all total eclipses through the continental USA for the next 1000 years (from 2001 through 3000). Courtesy of “Atlas of Central Solar Eclipses in the USA“.

There is something compelling about the pattern of eclipse tracks crossing familiar places many hundreds of years in the past and future. It was this fascination that inspired me to publish a new book “Atlas of Central Solar Eclipses in the USA.”


Fred Espenak


Atlas of Central Solar Eclipses in the USA contains maps and information on every total, annular and hybrid eclipse visible from the USA (including Alaska and Hawaii) for the 2000-year period 1001 to 3000.

Atlas of Central Solar Eclipses in the USA contains maps and information on every total, annular and hybrid eclipse visible from the USA (including Alaska and Hawaii) for the 2000-year period 1001 to 3000.

					

2017 Eclipse Bulletin

For over 40 years, the U. S. Naval Observatory produced a series of special publications known as the eclipse circulars. Each contained detailed predictions in the form of tables and maps for an upcoming total or annular solar eclipse and were of vital importance in the planning and execution of eclipse expeditions. Although intended for research scientists, the publications enjoyed an even greater circulation among amateur astronomers and eclipse chasers as the most authoritative guide and technical reference on each eclipse.

When the Naval Observatory terminated its eclipse circular series in 1992, they contacted me about producing a similar publication in support of the scientific community. At the time, I was an astrophysicist at NASA’s Goddard Space Flight Center working in the field of infrared spectroscopy. However, I had also published a number of eclipse prediction papers for major eclipses from 1979 through 1991, as well as the Fifty Year Canon of Solar Eclipses: 1986 – 2035.

Fortunately, my branch chief agreed to let me spend a small part of my time working on the new eclipse publications. Knowing that weather prospects along an eclipse track play a critical role in expedition planning, I invited Jay Anderson (meteorologist then working at Environment Canada) to join me as coauthor, and the NASA eclipse bulletin series was born.

These are the covers of the first 10 NASA eclipse bulletins published by Espenak and Anderson. All 13 bulletins are still available to download at: NASA Eclipse Bulletins

These are the covers of the first 10 NASA eclipse bulletins published by Espenak and Anderson. All 13 bulletins are still available to download at: NASA Eclipse Bulletins

From 1993 through 2008, Jay and I produced 13 eclipse bulletins in cooperation with the International Astronomical Union’s Working Group on Eclipses. Modest NASA funding allowed us to publish and distribute each bulletin to both the professional and lay communities, including educators and the media.

When I retired from NASA in 2009, funding ended for the eclipse bulletins. Various avenues were investigated for alternate funding without success. But with the recent development of print-on-demand publishing, another possibility presented itself. Using print-on-demand, it is no longer necessary to print thousands of books in advance, or handle inventory or shipping. To test it out, the print-on-demand process was used to produce the recent publication Thousand Year Canon of Solar Eclipses: 1501 – 2500.

The Thousand Year Canon of Solar Eclipses: 1501 - 2500 contains individual maps and data for each of the 2,389 solar eclipses occurring over the 1,000-year period centered on the present. For more information, see Thousand Year Canon of Solar Eclipses: 1501 to 2500.

The Thousand Year Canon of Solar Eclipses: 1501 – 2500 contains individual maps and data for each of the 2,389 solar eclipses occurring over the 1,000-year period centered on the present. For more information, see Thousand Year Canon of Solar Eclipses: 1501 to 2500.

I was anxious to master print-on-demand in order to publish new eclipse bulletins particularly because of the upcoming total solar eclipse of 2017 August 21. This is the first total eclipse visible from the contiguous United States since 1979.

The umbral path of the 2017 eclipse begins in the Pacific Ocean and crosses the USA from west to east through parts of the following states: Oregon, Idaho, Wyoming, Nebraska, Kansas, Missouri, Illinois, Kentucky, Tennessee, Georgia, North Carolina, and South Carolina. The Moon’s penumbral shadow produces a partial eclipse visible from a much larger region covering all of North America.

To find an umbral eclipse path covering a comparable amount of real estate in the USA, one must go back nearly a century to 1918. This rarity underscores the significance of the 2017 eclipse, which offers millions of Americans the opportunity to witness totality within 1,500 miles or less from home.

Michael Zeiler of GreatAmericanEclipse.com has created some beautiful maps of the umbral eclipse path for the 2017 Eclipse Bulletin.

Michael Zeiler of GreatAmericanEclipse.com has created some beautiful maps of the umbral eclipse path for the 2017 Eclipse Bulletin.

Note that much emphasis is placed on the eclipse’s umbral path (a.k.a. “path of totality”), which ranges in width from 62 to 71 miles as it crosses the USA. It is only inside this narrow path that the Moon will completely cover the Sun as the lunar shadow plunges the landscape into an eerie twilight and the Sun’s glorious corona is revealed for nearly 3 minutes.

Outside the path, only a partial eclipse is seen. Even if the the Moon covers 99% of the Sun, a partial eclipse does not even come close to the spectacle presented by a total eclipse. YOU MUST BE INSIDE THE UMBRAL PATH! (see The Experience of Totality)

Eclipse Bulletin: Total Solar Eclipse of 2017 August 21 contains detailed maps and local circumstances for over 1300 cities. It will become available to order on May 14, 2015.

Eclipse Bulletin: Total Solar Eclipse of 2017 August 21 contains detailed maps and local circumstances for over 1300 cities. It will become available to order on May 14, 2015.

Jay Anderson and I are pleased to announce the first of a new series of publications: Eclipse Bulletin: Total Solar Eclipse of 2017 August 21. It contains tables presenting the umbral shadow path coordinates, a physical ephemeris of the umbra, local circumstances on the central line, topocentric data and path corrections due to the lunar limb profile, and mapping coordinates for the zones of grazing eclipse. High-resolution maps plot the total eclipse path across the USA. They show hundreds of cities and towns in the path, the location of major roads and highways, and the duration of totality with distance from the central line.

Local circumstance tables for more than 1000 cities within the USA provide times of each phase of the eclipse along with the eclipse magnitude and duration. Additional tables cover the eclipse circumstances for cities in Canada, Mexico, and Central and South America as well as Western Europe and North Africa. An exhaustive climatological investigation identifies locations along the eclipse path where the highest probability of favorable weather may be found. A travelogue highlights key locations in the eclipse track from Oregon through South Carolina. Finally, comprehensive information is presented about solar filters and how to safely observe and photograph the eclipse.

And now for the first time, the Eclipse Bulletin is available in both the standard black & white edition as well as a deluxe color edition. Color offers a significant advantage in revealing details especially in figures, maps, and photographs.

The 2017 Eclipse Bulletin features a set of high-resolution maps of the umbral eclipse path across the USA. This one shows the path through western Oregon and includes many cities and towns as well as major roads and highways.

The 2017 Eclipse Bulletin features a set of high-resolution maps of the umbral eclipse path across the USA. This one shows the path through western Oregon and includes many cities and towns as well as major roads and highways.

Readers unfamiliar with the eclipse bulletins should know these books assume an intermediate level or higher understanding of eclipses. There are plenty of introductory books covering eclipses for beginners (for example, Totality: Eclipses of the Sun by Littmann, Espenak and Willcox, and The Sun in Eclipse by Maunder and Moore) so the basics won’t be covered here. Nevertheless, an effort has been made to make this new bulletin series more user friendly given the wide audience that has come to embrace these publications.

I am speaking at the Texas Star Party on May 13, where I will officially introduce the 2017 Eclipse Bulletin with copies to sign. The book will become available to order online here when I return on May 15.

Michael Zeiler of GreatAmericanEclipse.com called the 2017 Eclipse Bulletin “… the definitive reference for the 2017 eclipse and a must-get book for anyone doing planning for the eclipse.” Jay and I sincerely hope that it will help many people to witness nature’s most spectacular astronomical event visible to the naked-eye.

Clear skies on 2017 August 21!

Fred Espenak



March’s Eclipse and the Saros

This month’s total solar eclipse on March 20 belongs to a family of eclipses known as Saros 120. A Saros series is composed of a group of eclipses in which each eclipse is separated from the next (or previous) eclipse by 6,585.3 days. This equals 18 years 10 days 8 hours (or 18 years 11 days 8 hours, depending on the number of leap years over this interval).

The Saros period is special because any two eclipses separated by one Saros are very similar to each other. The Moon is nearly at the same position with respect to its node (the point where the Moon’s orbit crosses Earth’s orbit) and is also at almost the same distance from Earth. Not only that, the eclipse occurs at virtually the same time of year.

These coincidences arise because three of the Moon’s orbital periods repeat after one Saros period of 18 years 10.3 days. The three periods are:

Synodic Month (New Moon to New Moon)    = 29.531 days  = 29d 12h 44m
Draconic Month (node to node)           = 27.212 days  = 27d 05h 05m
Anomalistic Month (perigee to perigee)  = 27.555 days  = 27d 13h 18m

If you work out the math, you find that:


  223 Synodic Months        = 6585.322 days   = 6585d 07h 43m
  242 Draconic Months       = 6585.358 days   = 6585d 08h 35m
  239 Anomalistic Months    = 6585.538 days   = 6585d 12h 54m

The biggest drawback of the Saros period is that it’s not equal to a whole number of days. The extra 8 hours means that Earth rotates an additional 1/3 of a day so subsequent eclipses are visible from different parts of the globe. For solar eclipses in a Saros series, this means that each successive eclipse path shifts about 120 degrees westward.

The paths of solar eclipse of Saros 136 show a westward shift of about 120 degrees with each succeeding eclipse. The northward shift is due to the shift in the Moon's position with respect to its node. Drawing courtesy of Fred Espenak.

The paths of solar eclipse of Saros 136 show a westward shift of about 120 degrees with each succeeding eclipse. The northward shift is due to the shift in the Moon’s position with respect to its node. Drawing courtesy of Fred Espenak.

Of course, the agreement between the Moon’s three periods isn’t perfect over one Saros period. Consequently, a Saros series of eclipses has a finite lifetime lasting from 12 to 15 centuries. Each series begins with a small partial eclipse near one of the poles. Each partial eclipse grows larger as the Moon passes progressively closer to the node until its umbral shadow finally crosses Earth producing either a total or annular eclipse. After 50 or 60 of these central eclipses, the Saros series ends with a final group of partial eclipses at the opposite pole.

There are currently 40 different Saros series in progress, each one with its own assigned number. Some of them are relatively young like Saros 145 that includes the next American total solar eclipse on Aug. 21, 2017. Others are old like Saros 120.

This month’s total solar eclipse is the 61st eclipse of Saros 120. The family began with a series of 7 partial eclipses starting on May 27, 933. The first central eclipse was annular and took place on Aug. 11, 1059. After 24 more annular and 4 hybrid eclipses, the series changed to total on June 20, 1582. Subsequent members of Saros 120 were all total eclipses with maximum durations hovering around 2 minutes. One eclipse in the series occurred on Jan. 24, 1925 and passed through New Your City. Another eclipse on Feb. 26, 1979 was the most recent total solar eclipse visible from the continental United States.

The paths of the final 7 total solar eclipse of Saros 120 show both the westward and northern shift of the eclipse paths with each succeeding eclipse. The northward shift is due to the shift in the Moon's position with respect to its node. ©2015 by Fred Espenak.

The paths of the final 7 total solar eclipse of Saros 120 show both the westward and northern shift of the eclipse paths with each succeeding eclipse. The northward shift is due to the shift in the Moon’s position with respect to its node. ©2015 by Fred Espenak.

The Mar. 20, 2015 eclipse is the 25th total eclipse in the series and actually has one of the longest durations (2 minutes 47 seconds). The next member of the series occurs on Mar. 30, 2033 is the last total eclipse of Saros 120. The following 9 eclipses are all partial terminating with the final eclipse of the series on Jul. 07, 2195. Complete details for the 71 eclipses in the series (in the sequence of 7 partial, 25 annular, 4 hybrid, 26 total, and 9 partial) may be found at: Saros 120.

For more införmation on the Saros and eclipses, see:
Periodicity of Solar Eclipses.

The total solar eclipse of Mar. 20, 2015 is visible from within a wide corridor that traverses the North Atlantic. A partial eclipse is visible from Europe, North Africa and western Asia. ©2014 by Fred Espenak.

The total solar eclipse of Mar. 20, 2015 is visible from within a wide corridor that traverses the North Atlantic. A partial eclipse is visible from Europe, North Africa and western Asia. ©2014 by Fred Espenak.

Finally, for complete details on March’s solar eclipse, see:
Total Solar Eclipse of 2015 Mar 20.

Fred Espenak