Events for June 2017

The following table gives the date and time of important astronomical events for June 2017.

The time of each event is given in Greenwich Mean Time or GMT (a.k.a. Universal Time or UT). To convert GMT to Eastern Standard Time (EST) just subtract 5 hours. To convert GMT to other time zones, visit Time Zones. Some of the astronomical terms used in the calendar are explained in Definitions.

 Date    GMT   Astronomical Events for June 2017
------  -----  --------------------------------------------
        (h:m)
Jun 01  12:42  FIRST QUARTER MOON 
Jun 03  11     Venus at Greatest Elongation: 45.9°W
Jun 03  23:57  Jupiter 2.3°S of Moon
Jun 07  03:19  Mercury 5.3°S of Pleiades
Jun 08  22:21  Moon at Apogee: 406402 km
Jun 09  13:10  FULL MOON 
Jun 10  01:25  Saturn 3.1°S of Moon
Jun 13  00     Venus at Aphelion 
Jun 15  02:40  Moon at Descending Node 
Jun 15  09     Saturn at Opposition 
Jun 17  11:33  LAST QUARTER MOON 
Jun 19  13     Mercury at Perihelion 
Jun 20  21:13  Venus 2.4°N of Moon
Jun 21  04:25  Summer Solstice 
Jun 21  14     Mercury at Superior Conjunction 
Jun 22  14:23  Aldebaran 0.5°S of Moon
Jun 23  10:49  Moon at Perigee: 357938 km
Jun 24  02:31  NEW MOON 
Jun 26  11:18  Beehive 3.2°N of Moon
Jun 27  16:26  Moon at Ascending Node 
Jun 28  00:26  Regulus 0.1°N of Moon

As the events above transpire, I will post photographs of some of them at Recent Images.

Astronomical events calendars for complete years and for eight time zones are available through the links below.

Time Zones Calendars of Astronomical Events
Greenwich Mean Time 2017 2018 2019 2020 2021 2022
Atlantic Standard Time 2017 2018 2019 2020 2021 2022
Eastern Standard Time 2017 2018 2019 2020 2021 2022
Central Standard Time 2017 2018 2019 2020 2021 2022
Mountain Standard Time 2017 2018 2019 2020 2021 2022
Pacific Standard Time 2017 2018 2019 2020 2021 2022
Alaska Standard Time 2017 2018 2019 2020 2021 2022
Hawaii Standard Time 2017 2018 2019 2020 2021 2022

For additional years, see Calendars of Astronomical Events.

The astronomical highlight of 2017 is the Great American Total Solar Eclipse on August 21. This is the first total 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 information on all solar and lunar eclipses this year, see: Eclipses During 2017.

The Calendars of Astronomical Events were all generated by a computer program I wrote (with THINK Pascal running on a Macintosh G4) using Astronomical Algorithms (Jean Meeus).

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



Events for May 2017

The following table gives the date and time of important astronomical events for May_ 2017.

The time of each event is given in Greenwich Mean Time or GMT (a.k.a. Universal Time or UT). To convert GMT to Eastern Standard Time (EST) just subtract 5 hours. To convert GMT to other time zones, visit Time Zones. Some of the astronomical terms used in the calendar are explained in Definitions.

 Date    GMT   Astronomical Events for May_ 2017
------  -----  --------------------------------------------
        (h:m)
May 02  18:23  Beehive 3.6°N of Moon
May 03  02:47  FIRST QUARTER MOON 
May 04  09:49  Regulus 0.5°N of Moon
May 04  10:42  Moon at Ascending Node 
May 05  01     Eta-Aquarid Meteor Shower
May 05  13:51  Mars 6.1°N of Aldebaran
May 07  21:24  Jupiter 2.1°S of Moon
May 10  21:43  FULL MOON 
May 12  19:51  Moon at Apogee: 406212 km
May 13  23:07  Saturn 3.1°S of Moon
May 17  23     Mercury at Greatest Elongation: 25.8°W
May 19  00:33  LAST QUARTER MOON 
May 19  01:30  Moon at Descending Node 
May 22  12:32  Venus 2.4°N of Moon
May 24  01:20  Mercury 1.6°N of Moon
May 25  19:44  NEW MOON 
May 26  01:23  Moon at Perigee: 357210 km
May 30  01:50  Beehive 3.4°N of Moon
May 31  11:56  Moon at Ascending Node 
May 31  16:08  Regulus 0.3°N of Moon

As the events above transpire, I will post photographs of some of them at Recent Images.

Astronomical events calendars for complete years and for eight time zones are available through the links below.

Time Zones Calendars of Astronomical Events
Greenwich Mean Time 2017 2018 2019 2020 2021 2022
Atlantic Standard Time 2017 2018 2019 2020 2021 2022
Eastern Standard Time 2017 2018 2019 2020 2021 2022
Central Standard Time 2017 2018 2019 2020 2021 2022
Mountain Standard Time 2017 2018 2019 2020 2021 2022
Pacific Standard Time 2017 2018 2019 2020 2021 2022
Alaska Standard Time 2017 2018 2019 2020 2021 2022
Hawaii Standard Time 2017 2018 2019 2020 2021 2022

For additional years, see Calendars of Astronomical Events.

The astronomical highlight of 2017 is the Great American Total Solar Eclipse on August 21. This is the first total 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 information on all solar and lunar eclipses this year, see: Eclipses During 2017.

The Calendars of Astronomical Events were all generated by a computer program I wrote (with THINK Pascal running on a Macintosh G4) using Astronomical Algorithms (Jean Meeus).

Fred Espenak



Events for April 2017

The following table gives the date and time of important astronomical events for April 2017.

The time of each event is given in Greenwich Mean Time or GMT (a.k.a. Universal Time or UT). To convert GMT to Eastern Standard Time (EST) just subtract 5 hours. To convert GMT to other time zones, visit Time Zones. Some of the astronomical terms used in the calendar are explained in Definitions.

 Date    GMT   Astronomical Events for April 2017
------  -----  --------------------------------------------
        (h:m)
Apr 01  08:50  Aldebaran 0.3°S of Moon
Apr 01  10     Mercury at Greatest Elongation: 19.0°E
Apr 03  18:39  FIRST QUARTER MOON 
Apr 05  12:45  Beehive 3.8°N of Moon
Apr 07  04:30  Regulus 0.7°N of Moon
Apr 07  09:14  Moon at Ascending Node 
Apr 07  21     Jupiter at Opposition 
Apr 10  21:20  Jupiter 2.2°S of Moon
Apr 11  06:08  FULL MOON 
Apr 14  06     Uranus in Conjunction with Sun 
Apr 15  10:05  Moon at Apogee: 405478 km
Apr 16  18:39  Saturn 3.2°S of Moon
Apr 19  09:57  LAST QUARTER MOON 
Apr 20  06     Mercury at Inferior Conjunction 
Apr 21  08:16  Mars 3.4°S of Pleiades
Apr 21  22:30  Moon at Descending Node 
Apr 22  12     Lyrid Meteor Shower
Apr 23  17:59  Venus 5.2°N of Moon
Apr 26  12:16  NEW MOON 
Apr 27  16:18  Moon at Perigee: 359325 km
Apr 28  17:19  Aldebaran 0.5°S of Moon

As the events above transpire, I will post photographs of some of them at Recent Images.

Astronomical events calendars for complete years and for eight time zones are available through the links below.

Time Zones Calendars of Astronomical Events
Greenwich Mean Time 2017 2018 2019 2020 2021 2022
Atlantic Standard Time 2017 2018 2019 2020 2021 2022
Eastern Standard Time 2017 2018 2019 2020 2021 2022
Central Standard Time 2017 2018 2019 2020 2021 2022
Mountain Standard Time 2017 2018 2019 2020 2021 2022
Pacific Standard Time 2017 2018 2019 2020 2021 2022
Alaska Standard Time 2017 2018 2019 2020 2021 2022
Hawaii Standard Time 2017 2018 2019 2020 2021 2022

For additional years, see Calendars of Astronomical Events.

The astronomical highlight of 2017 is the Great American Total Solar Eclipse on August 21. This is the first total 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 information on all solar and lunar eclipses this year, see: Eclipses During 2017.

The Calendars of Astronomical Events were all generated by a computer program I wrote (with THINK Pascal running on a Macintosh G4) using Astronomical Algorithms (Jean Meeus).

Fred Espenak



Events for March 2017

The following table gives the date and time of important astronomical events for March 2017.

The time of each event is given in Greenwich Mean Time or GMT (a.k.a. Universal Time or UT). To convert GMT to Eastern Standard Time (EST) just subtract 5 hours. To convert GMT to other time zones, visit Time Zones. Some of the astronomical terms used in the calendar are explained in Definitions.

 Date    GMT   Astronomical Events for March 2017
------  -----  --------------------------------------------
        (h:m)
Mar 01  18:58  Mars 4.3°N of Moon
Mar 02  02     Neptune in Conjunction with Sun 
Mar 03  07:24  Moon at Perigee: 369065 km
Mar 05  02:38  Aldebaran 0.2°S of Moon
Mar 05  11:32  FIRST QUARTER MOON 
Mar 07  00     Mercury at Superior Conjunction 
Mar 09  07:12  Beehive 3.9°N of Moon
Mar 10  22:20  Regulus 0.8°N of Moon
Mar 11  04:17  Moon at Ascending Node 
Mar 12  14:54  FULL MOON 
Mar 14  20:04  Jupiter 2.5°S of Moon
Mar 18  17:25  Moon at Apogee: 404651 km
Mar 20  10:29  Vernal Equinox 
Mar 20  10:49  Saturn 3.4°S of Moon
Mar 20  15:58  LAST QUARTER MOON 
Mar 23  14     Mercury at Perihelion 
Mar 25  11     Venus at Inferior Conjunction 
Mar 25  15:41  Moon at Descending Node 
Mar 28  02:57  NEW MOON 
Mar 30  12:39  Moon at Perigee: 363855 km
Mar 30  13:03  Mars 5.5°N of Moon

As the events above transpire, I will post photographs of some of them at Recent Images.

Astronomical events calendars for complete years and for eight time zones are available through the links below.

Time Zones Calendars of Astronomical Events
Greenwich Mean Time 2017 2018 2019 2020 2021 2022
Atlantic Standard Time 2017 2018 2019 2020 2021 2022
Eastern Standard Time 2017 2018 2019 2020 2021 2022
Central Standard Time 2017 2018 2019 2020 2021 2022
Mountain Standard Time 2017 2018 2019 2020 2021 2022
Pacific Standard Time 2017 2018 2019 2020 2021 2022
Alaska Standard Time 2017 2018 2019 2020 2021 2022
Hawaii Standard Time 2017 2018 2019 2020 2021 2022

For additional years, see Calendars of Astronomical Events.

The astronomical highlight of 2017 is the Great American Total Solar Eclipse on August 21. This is the first total 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 information on all solar and lunar eclipses this year, see: Eclipses During 2017.

The Calendars of Astronomical Events were all generated by a computer program I wrote (with THINK Pascal running on a Macintosh G4) using Astronomical Algorithms (Jean Meeus).

Fred Espenak



Events for February 2017

The following table gives the date and time of important astronomical events for February 2017.

The time of each event is given in Greenwich Mean Time or GMT (a.k.a. Universal Time or UT). To convert GMT to Eastern Standard Time (EST) just subtract 5 hours. To convert GMT to other time zones, visit Time Zones. Some of the astronomical terms used in the calendar are explained in Definitions.

 Date    GMT   Astronomical Events for February 2017
------  -----  --------------------------------------------
        (h:m)
Feb 01  01:09  Mars 2.3°N of Moon
Feb 04  04:19  FIRST QUARTER MOON 
Feb 05  21:14  Aldebaran 0.2°S of Moon
Feb 06  13:59  Moon at Perigee: 368817 km
Feb 07  14     Mercury at Aphelion 
Feb 09  23:46  Beehive 3.9°N of Moon
Feb 11  00:33  FULL MOON 
Feb 11  00:44  Penumbral Lunar Eclipse; mag=0.988
Feb 11  14:04  Regulus 0.8°N of Moon
Feb 11  19:49  Moon at Ascending Node 
Feb 15  14:55  Jupiter 2.7°S of Moon
Feb 18  19:33  LAST QUARTER MOON 
Feb 18  21     Jupiter at Aphelion 
Feb 18  21:14  Moon at Apogee: 404376 km
Feb 20  16     Venus at Perihelion 
Feb 20  23:44  Saturn 3.6°S of Moon
Feb 26  06:28  Moon at Descending Node 
Feb 26  14:53  Annular Solar Eclipse; mag=0.992
Feb 26  14:58  NEW MOON 

As the events above transpire, I will post photographs of some of them at Recent Images.

Astronomical events calendars for complete years and for eight time zones are available through the links below.

Time Zones Calendars of Astronomical Events
Greenwich Mean Time 2017 2018 2019 2020 2021 2022
Atlantic Standard Time 2017 2018 2019 2020 2021 2022
Eastern Standard Time 2017 2018 2019 2020 2021 2022
Central Standard Time 2017 2018 2019 2020 2021 2022
Mountain Standard Time 2017 2018 2019 2020 2021 2022
Pacific Standard Time 2017 2018 2019 2020 2021 2022
Alaska Standard Time 2017 2018 2019 2020 2021 2022
Hawaii Standard Time 2017 2018 2019 2020 2021 2022

For additional years, see Calendars of Astronomical Events.

The astronomical highlight of 2017 is the Great American Total Solar Eclipse on August 21. This is the first total 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 information on all solar and lunar eclipses this year, see: Eclipses During 2017.

The Calendars of Astronomical Events were all generated by a computer program I wrote (with THINK Pascal running on a Macintosh G4) using Astronomical Algorithms (Jean Meeus).

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


Events for January 2017

The following table gives the date and time of important astronomical events for January 2017.

The time of each event is given in Greenwich Mean Time or GMT (a.k.a. Universal Time or UT). To convert GMT to Eastern Standard Time (EST) just subtract 5 hours. To convert GMT to other time zones, visit Time Zones. Some of the astronomical terms used in the calendar are explained in Definitions.

 Date    GMT   Astronomical Events for January 2017
------  -----  --------------------------------------------
        (h:m)
Jan 02  09:20  Venus 1.9°S of Moon
Jan 02  18:14  Moon at Descending Node 
Jan 03  06:47  Mars 0.2°S of Moon: Occultation
Jan 03  14     Quadrantid Meteor Shower
Jan 04  15     Earth at Perihelion: 0.98331 AU
Jan 05  19:47  FIRST QUARTER MOON 
Jan 09  09     Mercury 6.7° of Saturn
Jan 09  14:07  Aldebaran 0.4°S of Moon
Jan 10  06:07  Moon at Perigee: 363242 km
Jan 12  11:34  FULL MOON 
Jan 12  13     Venus at Greatest Elongation: 47.1°E
Jan 13  13:59  Beehive 3.9°N of Moon
Jan 15  04:07  Regulus 0.9°N of Moon
Jan 15  10:44  Moon at Ascending Node 
Jan 19  05:26  Jupiter 2.7°S of Moon
Jan 19  10     Mercury at Greatest Elongation: 24.1°W
Jan 19  22:14  LAST QUARTER MOON 
Jan 22  00:14  Moon at Apogee: 404913 km
Jan 24  10:37  Saturn 3.6°S of Moon
Jan 26  00:46  Mercury 3.7°S of Moon
Jan 28  00:07  NEW MOON 
Jan 29  22:21  Moon at Descending Node 
Jan 31  13:11  Jupiter 3.5°N of Spica
Jan 31  14:34  Venus 4.1°N of Moon

As the events above transpire, I will post photographs of some of them at Recent Images.

Astronomical events calendars for complete years and for eight time zones are available through the links below.

Time Zones Calendars of Astronomical Events
Greenwich Mean Time 2017 2018 2019 2020 2021 2022
Atlantic Standard Time 2017 2018 2019 2020 2021 2022
Eastern Standard Time 2017 2018 2019 2020 2021 2022
Central Standard Time 2017 2018 2019 2020 2021 2022
Mountain Standard Time 2017 2018 2019 2020 2021 2022
Pacific Standard Time 2017 2018 2019 2020 2021 2022
Alaska Standard Time 2017 2018 2019 2020 2021 2022
Hawaii Standard Time 2017 2018 2019 2020 2021 2022

For additional years, see Calendars of Astronomical Events.

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 astronomical highlight of 2017 is the Great American Total Solar Eclipse on August 21. This is the first total 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 information on all solar and lunar eclipses this year, see: Eclipses During 2017.

The Calendars of Astronomical Events were all generated by a computer program I wrote (with THINK Pascal running on a Macintosh G4) using Astronomical Algorithms (Jean Meeus).

Fred Espenak



Events for December 2016

The following table gives the date and time of important astronomical events for December 2016. The time of each event is given in Greenwich Mean Time or GMT (a.k.a. Universal Time or UT). To convert GMT to Eastern Standard Time (EST) just subtract 5 hours. To convert GMT to other time zones, visit Time Zones. Some of the astronomical terms used in the calendar are explained in Definitions.

 Date    GMT   Astronomical Events for December 2016
------  -----  --------------------------------------------
        (h:m)
Dec 03  12:34  Venus 5.8°S of Moon
Dec 05  10:39  Mars 2.9°S of Moon
Dec 06  17:35  Moon at Descending Node 
Dec 07  09:03  FIRST QUARTER MOON 
Dec 10  11     Saturn in Conjunction with Sun 
Dec 11  04     Mercury at Greatest Elongation: 20.8°E
Dec 12  23:27  Moon at Perigee: 358463 km
Dec 13  04:14  Aldebaran 0.5°S of Moon
Dec 14  00     Geminid Meteor Shower
Dec 14  00:06  FULL MOON 
Dec 17  03:17  Beehive 4.1°N of Moon
Dec 18  18:13  Regulus 1.0°N of Moon
Dec 19  04:46  Moon at Ascending Node 
Dec 21  01:56  LAST QUARTER MOON 
Dec 21  10:45  Winter Solstice 
Dec 22  08     Ursid Meteor Shower
Dec 22  16:37  Jupiter 2.4°S of Moon
Dec 25  05:55  Moon at Apogee: 405870 km
Dec 25  15     Mercury at Perihelion 
Dec 28  19     Mercury at Inferior Conjunction 
Dec 29  06:53  NEW MOON 

As the events above transpire, I will occassionally post photographs of some of them at Recent Images.

Astronomical events calendars for complete years and for eight time zones are available through the links below.

Time Zones Calendars of Astronomical Events
Greenwich Mean Time 2016 2017 2018 2019 2020 2021
Atlantic Standard Time 2016 2017 2018 2019 2020 2021
Eastern Standard Time 2016 2017 2018 2019 2020 2021
Central Standard Time 2016 2017 2018 2019 2020 2021
Mountain Standard Time 2016 2017 2018 2019 2020 2021
Pacific Standard Time 2016 2017 2018 2019 2020 2021
Alaska Standard Time 2016 2017 2018 2019 2020 2021
Hawaii Standard Time 2016 2017 2018 2019 2020 2021

For additional years, see Calendars of Astronomical Events.

For detailed information on solar and lunar eclipses this year, see: Eclipses During 2016.

For detailed information on the transit of Mercury this year, see: 2016 Transit of Mercury.

The Calendars of Astronomical Events were all generated by a computer program I wrote (with THINK Pascal running on a Macintosh G4) using Astronomical Algorithms (Jean Meeus).

Fred Espenak