Events for July 2015

The following table gives the date and time of important astronomical events for July 2015. 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 July 2015
------  -----  --------------------------------------------
        (h:m)
Jul 02  02:20  FULL MOON 
Jul 05  18:54  Moon at Perigee: 367095 km
Jul 06  19     Earth at Aphelion: 1.01668 AU
Jul 08  00:07  Moon at Descending Node 
Jul 08  20:24  LAST QUARTER MOON 
Jul 12  17:55  Aldebaran 0.9°S of Moon
Jul 14  21:15  Venus 1.5°S of Regulus
Jul 16  01:24  NEW MOON 
Jul 16  19     Mercury at Perihelion 
Jul 18  17:34  Jupiter 4.1°N of Moon
Jul 19  01:06  Venus 0.4°N of Moon: Occultation
Jul 19  02:49  Regulus 3.4°N of Moon
Jul 21  11:02  Moon at Apogee: 404837 km
Jul 21  19:32  Moon at Ascending Node 
Jul 23  10:45  Spica 4.0°S of Moon
Jul 23  19     Mercury at Superior Conjunction 
Jul 24  04:04  FIRST QUARTER MOON 
Jul 26  08:43  Saturn 2.2°S of Moon
Jul 28  14     Delta-Aquarid Meteor Shower
Jul 31  10:43  FULL 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 2015 2016 2017 2018 2019 2020
Atlantic Standard Time 2015 2016 2017 2018 2019 2020
Eastern Standard Time 2015 2016 2017 2018 2019 2020
Central Standard Time 2015 2016 2017 2018 2019 2020
Mountain Standard Time 2015 2016 2017 2018 2019 2020
Pacific Standard Time 2015 2016 2017 2018 2019 2020
Alaska Standard Time 2015 2016 2017 2018 2019 2020
Hawaii Standard Time 2015 2016 2017 2018 2019 2020

For additional years, see Calendars of Astronomical Events.

For detailed information on solar and lunar eclipses this year, see: Eclipses During 2015.

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 June 2015

The following table gives the date and time of important astronomical events for June 2015. 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 2015
------  -----  --------------------------------------------
        (h:m)
Jun 01  20:02  Saturn 1.9°S of Moon
Jun 02  16:19  FULL MOON 
Jun 06  19     Venus at Greatest Elongation: 45.4°E
Jun 09  15:42  LAST QUARTER MOON 
Jun 10  04:39  Moon at Perigee: 369713 km
Jun 10  23:30  Moon at Descending Node 
Jun 13  08:59  Venus 0.5°N of Beehive
Jun 14  15     Mars in Conjunction with Sun 
Jun 15  02:26  Mercury 0.0°N of Moon: Occultation
Jun 16  14:05  NEW MOON 
Jun 20  11:28  Venus 5.8°N of Moon
Jun 20  23:29  Jupiter 4.7°N of Moon
Jun 21  16:38  Summer Solstice 
Jun 21  19:10  Regulus 3.6°N of Moon
Jun 23  09:37  Mercury 1.8°N of Aldebaran
Jun 23  17:01  Moon at Apogee: 404134 km
Jun 24  11:03  FIRST QUARTER MOON 
Jun 24  17     Mercury at Greatest Elongation: 22.5°W
Jun 24  17:23  Moon at Ascending Node 
Jun 26  02:58  Spica 3.8°S of Moon
Jun 29  01:27  Saturn 2.0°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 2015 2016 2017 2018 2019 2020
Atlantic Standard Time 2015 2016 2017 2018 2019 2020
Eastern Standard Time 2015 2016 2017 2018 2019 2020
Central Standard Time 2015 2016 2017 2018 2019 2020
Mountain Standard Time 2015 2016 2017 2018 2019 2020
Pacific Standard Time 2015 2016 2017 2018 2019 2020
Alaska Standard Time 2015 2016 2017 2018 2019 2020
Hawaii Standard Time 2015 2016 2017 2018 2019 2020

For additional years, see Calendars of Astronomical Events.

For detailed information on solar and lunar eclipses this year, see: Eclipses During 2015.

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



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



Events for May 2015

The following table gives the date and time of important astronomical events for May 2015. 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_ 2015
------  -----  --------------------------------------------
        (h:m)
May 01  01:29  Mercury 1.6°S of Pleiades
May 01  09:50  Moon at Ascending Node 
May 02  11:10  Spica 3.5°S of Moon
May 04  03:42  FULL MOON 
May 05  13     Eta-Aquarid Meteor Shower
May 05  16:19  Saturn 2.0°S of Moon
May 07  05     Mercury at Greatest Elongation: 21.2°E
May 11  10:36  LAST QUARTER MOON 
May 14  20:37  Moon at Descending Node 
May 15  00:23  Moon at Perigee: 366024 km
May 18  04:13  NEW MOON 
May 19  06:51  Mercury 5.7°N of Moon
May 23  01     Saturn at Opposition 
May 24  07:03  Jupiter 5.1°N of Moon
May 25  11:14  Regulus 3.8°N of Moon
May 25  17:19  FIRST QUARTER MOON 
May 26  22:12  Moon at Apogee: 404246 km
May 28  14:40  Moon at Ascending Node 
May 29  17:27  Venus 3.9°S of Pollux
May 29  18:52  Spica 3.6°S of Moon
May 30  17     Mercury at Inferior Conjunction 

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 2015 2016 2017 2018 2019 2020
Atlantic Standard Time 2015 2016 2017 2018 2019 2020
Eastern Standard Time 2015 2016 2017 2018 2019 2020
Central Standard Time 2015 2016 2017 2018 2019 2020
Mountain Standard Time 2015 2016 2017 2018 2019 2020
Pacific Standard Time 2015 2016 2017 2018 2019 2020
Alaska Standard Time 2015 2016 2017 2018 2019 2020
Hawaii Standard Time 2015 2016 2017 2018 2019 2020

For additional years, see Calendars of Astronomical Events.

For detailed information on solar and lunar eclipses this year, see: Eclipses During 2015.

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 2015

The following table gives the date and time of important astronomical events for April 2015. 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 2015
------  -----  --------------------------------------------
        (h:m)
Apr 01  12:59  Moon at Apogee: 406012 km
Apr 04  03:17  Moon at Ascending Node 
Apr 04  12:00  Total Lunar Eclipse; mag=1.001
Apr 04  12:06  FULL MOON 
Apr 05  04:21  Spica 3.5°S of Moon
Apr 06  14     Uranus in Conjunction with Sun 
Apr 08  13:08  Saturn 2.2°S of Moon
Apr 08  14:34  Jupiter 2.0°S of Beehive
Apr 10  04     Mercury at Superior Conjunction 
Apr 11  15:28  Venus 2.5°S of Pleiades
Apr 12  03:44  LAST QUARTER MOON 
Apr 17  03:53  Moon at Perigee: 361026 km
Apr 17  13:07  Moon at Descending Node 
Apr 18  13     Venus at Perihelion 
Apr 18  18:57  NEW MOON 
Apr 19  19:24  Venus 7.2°N of Aldebaran
Apr 19  20     Mercury at Perihelion 
Apr 21  16:35  Aldebaran 0.9°S of Moon
Apr 22  19     Mercury 1.3° of Mars
Apr 22  23     Lyrid Meteor Shower
Apr 25  23:55  FIRST QUARTER MOON 
Apr 26  18:06  Jupiter 5.5°N of Moon
Apr 28  03:38  Regulus 4.0°N of Moon
Apr 29  03:55  Moon at Apogee: 405085 km

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 2015 2016 2017 2018 2019 2020
Atlantic Standard Time 2015 2016 2017 2018 2019 2020
Eastern Standard Time 2015 2016 2017 2018 2019 2020
Central Standard Time 2015 2016 2017 2018 2019 2020
Mountain Standard Time 2015 2016 2017 2018 2019 2020
Pacific Standard Time 2015 2016 2017 2018 2019 2020
Alaska Standard Time 2015 2016 2017 2018 2019 2020
Hawaii Standard Time 2015 2016 2017 2018 2019 2020

For additional years, see Calendars of Astronomical Events.

For detailed information on solar and lunar eclipses this year, see: Eclipses During 2015.

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



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


Events for March 2015

The following table gives the date and time of important astronomical events for March 2015. 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 2015
------  -----  --------------------------------------------
        (h:m)
Mar 03  07:56  Jupiter 5.5°N of Moon
Mar 04  14:29  Regulus 4.0°N of Moon
Mar 05  07:35  Moon at Apogee: 406386 km
Mar 05  18:05  FULL MOON 
Mar 06  20     Mercury at Aphelion 
Mar 07  21:04  Moon at Ascending Node 
Mar 08  22:21  Spica 3.4°S of Moon
Mar 12  08:25  Saturn 2.3°S of Moon
Mar 13  17:48  LAST QUARTER MOON 
Mar 19  04:57  Mercury 5.2°S of Moon
Mar 19  19:38  Moon at Perigee: 357584 km
Mar 20  09:36  NEW MOON 
Mar 20  09:46  Total Solar Eclipse; mag=1.045
Mar 20  22:45  Vernal Equinox 
Mar 21  02:19  Moon at Descending Node 
Mar 21  22:13  Mars 1.0°N of Moon: Occultation
Mar 22  19:51  Venus 2.8°N of Moon
Mar 25  06:55  Aldebaran 0.9°S of Moon
Mar 27  07:43  FIRST QUARTER MOON 
Mar 30  10:19  Jupiter 5.6°N of Moon
Mar 31  20:45  Regulus 4.0°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 2015 2016 2017 2018 2019 2020
Atlantic Standard Time 2015 2016 2017 2018 2019 2020
Eastern Standard Time 2015 2016 2017 2018 2019 2020
Central Standard Time 2015 2016 2017 2018 2019 2020
Mountain Standard Time 2015 2016 2017 2018 2019 2020
Pacific Standard Time 2015 2016 2017 2018 2019 2020
Alaska Standard Time 2015 2016 2017 2018 2019 2020
Hawaii Standard Time 2015 2016 2017 2018 2019 2020

For additional years, see Calendars of Astronomical Events.

For detailed information on solar and lunar eclipses this year, see: Eclipses During 2015.

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 2015

The following table gives the date and time of important astronomical events for February 2015. 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 2015
------  -----  --------------------------------------------
        (h:m)
Feb 03  23:09  FULL MOON 
Feb 04  08:35  Jupiter 5.2°N of Moon
Feb 05  08:17  Regulus 4.0°N of Moon
Feb 06  06:25  Moon at Apogee: 406155 km
Feb 06  17     Jupiter at Opposition 
Feb 08  17:10  Moon at Ascending Node 
Feb 09  16:23  Spica 3.3°S of Moon
Feb 12  03:50  LAST QUARTER MOON 
Feb 13  00:10  Saturn 2.1°S of Moon
Feb 17  06:20  Mercury 3.5°S of Moon
Feb 18  23:47  NEW MOON 
Feb 19  07:29  Moon at Perigee: 356992 km
Feb 21  00:56  Venus 2.0°S of Moon
Feb 21  01:28  Mars 1.5°S of Moon
Feb 21  16:05  Moon at Descending Node 
Feb 24  16     Mercury at Greatest Elongation: 26.7°W
Feb 25  17:14  FIRST QUARTER MOON 
Feb 25  23:02  Aldebaran 1.0°S of Moon
Feb 26  04     Neptune in Conjunction with Sun 

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 2015 2016 2017 2018 2019 2020
Atlantic Standard Time 2015 2016 2017 2018 2019 2020
Eastern Standard Time 2015 2016 2017 2018 2019 2020
Central Standard Time 2015 2016 2017 2018 2019 2020
Mountain Standard Time 2015 2016 2017 2018 2019 2020
Pacific Standard Time 2015 2016 2017 2018 2019 2020
Alaska Standard Time 2015 2016 2017 2018 2019 2020
Hawaii Standard Time 2015 2016 2017 2018 2019 2020

For additional years, see Calendars of Astronomical Events.

For detailed information on solar and lunar eclipses this year, see: Eclipses During 2015.

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 January 2015

The following table gives the date and time of important astronomical events for January 2015. 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 2015
------  -----  --------------------------------------------
        (h:m)
Jan 02  11:35  Aldebaran 1.4°S of Moon
Jan 04  02     Quadrantid Meteor Shower
Jan 04  06     Earth at Perihelion: 0.98328 AU
Jan 05  04:53  FULL MOON 
Jan 08  08:16  Jupiter 5.1°N of Moon
Jan 09  01:34  Regulus 4.1°N of Moon
Jan 09  18:17  Moon at Apogee: 405411 km
Jan 11  01     Mercury 0.6° of Venus
Jan 12  15:33  Moon at Ascending Node 
Jan 13  09:27  Spica 3.1°S of Moon
Jan 13  09:47  LAST QUARTER MOON 
Jan 14  20     Mercury at Greatest Elongation: 18.9°E
Jan 16  11:52  Saturn 1.9°S of Moon
Jan 20  13:14  NEW MOON 
Jan 21  17:39  Mercury 3.0°S of Moon
Jan 21  20:06  Moon at Perigee: 359643 km
Jan 21  21     Mercury at Perihelion 
Jan 22  05:01  Venus 5.6°S of Moon
Jan 23  04:40  Mars 3.9°S of Moon
Jan 25  10:23  Moon at Descending Node 
Jan 27  04:48  FIRST QUARTER MOON 
Jan 29  17:07  Aldebaran 1.2°S of Moon
Jan 30  14     Mercury at Inferior Conjunction 

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 2015 2016 2017 2018 2019 2020
Atlantic Standard Time 2015 2016 2017 2018 2019 2020
Eastern Standard Time 2015 2016 2017 2018 2019 2020
Central Standard Time 2015 2016 2017 2018 2019 2020
Mountain Standard Time 2015 2016 2017 2018 2019 2020
Pacific Standard Time 2015 2016 2017 2018 2019 2020
Alaska Standard Time 2015 2016 2017 2018 2019 2020
Hawaii Standard Time 2015 2016 2017 2018 2019 2020

For additional years, see Calendars of Astronomical Events.

For detailed information on solar and lunar eclipses this year, see: Eclipses During 2015.

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 2015

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.

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 29.53 days.

                    Moon Phases for 2015 (GMT)

   New Moon       First Quarter       Full Moon        Last Quarter
-------------     -------------     -------------     -------------   
                                    Jan  5  04:53     Jan 13  09:47    
Jan 20  13:14     Jan 27  04:48     Feb  3  23:09     Feb 12  03:50    
Feb 18  23:47     Feb 25  17:14     Mar  5  18:06     Mar 13  17:48    
Mar 20  09:36 T   Mar 27  07:43     Apr  4  12:06 t   Apr 12  03:44    
Apr 18  18:57     Apr 25  23:55     May  4  03:42     May 11  10:36    
May 18  04:13     May 25  17:19     Jun  2  16:19     Jun  9  15:42    
Jun 16  14:05     Jun 24  11:03     Jul  2  02:20     Jul  8  20:24    
Jul 16  01:24     Jul 24  04:04     Jul 31  10:43     Aug  7  02:03    
Aug 14  14:54     Aug 22  19:31     Aug 29  18:35     Sep  5  09:54    
Sep 13  06:41 P   Sep 21  08:59     Sep 28  02:50 t   Oct  4  21:06    
Oct 13  00:06     Oct 20  20:31     Oct 27  12:05     Nov  3  12:24    
Nov 11  17:47     Nov 19  06:27     Nov 25  22:44     Dec  3  07:40    
Dec 11  10:29     Dec 18  15:14     Dec 25  11:11                      

The table above lists the date and time of the Moon’s phases throughout 2015. The time of each phase is given in Greenwich Mean Time or GMT (a.k.a. Universal Time or UT). I’ve generated a table of the Moon’s phases covering 100 years 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.

What surprises many people is that the length of the synodic month can vary by over 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 2015. For instance, the fourth synodic month of 2015 (beginning Apr 18) is 3 hours 28 minutes shorter than the mean while the tenth month (beginning Oct 13) is 4 hours 57 minutes longer than the mean.

              Synodic Months for 2015 

   Date/Time of          Length of        Dif. from
  New Moon (GMT)       Synodic Month      Mean Month 
------------------     -------------     -----------
2015 Jan 20  13:14      29d 10h 34m       -02h 10m
2015 Feb 18  23:47      29d 09h 49m       -02h 55m
2015 Mar 20  09:36      29d 09h 21m       -03h 23m
2015 Apr 18  18:57      29d 09h 16m       -03h 28m     shortest
2015 May 18  04:13      29d 09h 52m       -02h 52m
2015 Jun 16  14:05      29d 11h 19m       -01h 25m
2015 Jul 16  01:24      29d 13h 29m       +00h 45m
2015 Aug 14  14:53      29d 15h 48m       +03h 04m
2015 Sep 13  06:41      29d 17h 24m       +04h 40m
2015 Oct 13  00:06      29d 17h 41m       +04h 57m     longest
2015 Nov 11  17:47      29d 16h 42m       +03h 58m      
2015 Dec 11  10:29      29d 15h 01m       +02h 17m   

The year 2008 had even greater extremes in the synodic month – from 5 hours 48 minutes shorter, to 6 hours 49 minutes longer than the mean value. So what causes these variations? The explanation lies in the fact that the Moon’s orbit is elliptical. 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. You can also find the duration of every synodic month this century at Length of the Synodic Month: 2001 to 2100.

Because the Moon orbits Earth in ~29.5 days with respect to the Sun, its daily motion against the background stars and constellations is quite rapid. It averages about 12.2° per day. A table giving the Moon’s daily celestial coordinates throughout the year can be found at Moon Ephemeris for 2015. This table lists a lot of other details about the Moon including its daily distance, apparent size, libration, phase age (days since New Moon) and the phase illumination fraction.

When a Full Moon occurs within 90% of the Moon’s closest approach to Earth in a given orbit, it is called a Super Moon. The Full Moon then appears especially big and bright since it subtends its largest apparent diameter as seen from Earth. The table below lists the Super Moons occurring in 2015.

              Super Moons for 2015

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

Jul 31  10:43     365112     32.73    0.930
Aug 29  18:35     358993     33.29    0.985
Sep 28  02:50 t   356878 m   33.48    1.000
Oct 27  12:05     359324     33.26    0.982
Nov 25  22:44     366149     32.64    0.921

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.

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 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 thumbnails 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 images from the Lunar Reconnaissance Orbiter (LRO) mission to create clever animations of the Moon’s ever changing phases and librations in 2015. The example below illustrates the Moon’s phase and libration at hourly intervals throughout 2015, as viewed from the northern hemisphere. Each frame represents one hour.

Besides presenting the Moon’s phase and apparent size, the video shows the Moon’s orbit 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. The major cause of libration is due to our changing line of sight because of the Moon’s elliptical orbit. For more Moon animations from NASA/Goddard, see Moon Phase and Libration, 2015.

Finally, what discussion of the Moon would be complete without mentioning eclipses in 2015? There are two eclipses of the Moon and both of them are total. The first occurs on April 04 and the second, six months later on September 28. Both of them are visible from parts of North America. By coincidence, the September 28 eclipse also happens to be the closest Super Moon of 2015.

There are also two solar eclipses in 2015. The first is a total eclipse in the North Atlantic on March 20 (visible from the Faroe Islands and Spitzbergen). The second is a partial solar eclipse visible from most of southern Africa and Antarctica on September 13. For complete details on all these events, see Eclipses During 2015 (EclipseWise.com).

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) using Astronomical Algorithms (Jean Meeus).

Fred Espenak