Events for June 2016

The following table gives the date and time of important astronomical events for June 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 June 2016
------  -----  --------------------------------------------
        (h:m)
Jun 03  06     Saturn at Opposition 
Jun 03  09:47  Mercury 0.7°N of Moon: Occultation
Jun 03  10:55  Moon at Perigee: 361142 km
Jun 05  03:00  NEW MOON 
Jun 05  09     Mercury at Greatest Elongation: 24.2°W
Jun 06  22     Venus at Superior Conjunction 
Jun 10  14:47  Regulus 2.0°N of Moon
Jun 11  19:35  Jupiter 1.5°N of Moon
Jun 11  22:20  Moon at Ascending Node 
Jun 12  08:10  FIRST QUARTER MOON 
Jun 13  10:06  Mercury 6.4°S of Pleiades
Jun 14  20:47  Spica 5.3°S of Moon
Jun 15  12:00  Moon at Apogee: 405022 km
Jun 19  00:40  Saturn 3.3°S of Moon
Jun 19  03:39  Mercury 3.7°N of Aldebaran
Jun 20  11:02  FULL MOON 
Jun 20  22:35  Summer Solstice 
Jun 26  05:28  Moon at Descending Node 
Jun 27  18:19  LAST QUARTER 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



Events for May 2016

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

Of special note this month is a rare transit of Mercury across the Sun’s disk on May 9.

 Date    GMT   Astronomical Events for May_ 2016
------  -----  --------------------------------------------
        (h:m)
May 03  01:27  Moon at Descending Node 
May 04  19     Eta-Aquarid Meteor Shower
May 06  04:14  Moon at Perigee: 357828 km
May 06  19:30  NEW MOON 
May 08  08:21  Aldebaran 0.5°S of Moon
May 09  15     Mercury at Inferior Conjunction 
May 09  15     Transit of Mercury Across Sun 
May 13  17:02  FIRST QUARTER MOON 
May 14  07:06  Regulus 2.3°N of Moon
May 15  09:30  Jupiter 2.0°N of Moon
May 15  20:39  Moon at Ascending Node 
May 18  14:07  Spica 5.1°S of Moon
May 18  22:06  Moon at Apogee: 405934 km
May 21  21:15  FULL MOON 
May 22  11     Mars at Opposition 
May 22  21:59  Saturn 3.2°S of Moon
May 29  12:12  LAST QUARTER MOON 
May 30  04:45  Moon at Descending Node 

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



Events for April 2016

The following table gives the date and time of important astronomical events for April 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 April 2016
------  -----  --------------------------------------------
        (h:m)
Apr 05  17     Mercury at Perihelion 
Apr 05  17:27  Moon at Descending Node 
Apr 06  08:30  Venus 0.7°S of Moon: Occultation
Apr 07  11:24  NEW MOON 
Apr 07  17:36  Moon at Perigee: 357164 km
Apr 08  10:35  Mercury 5.2°N of Moon
Apr 09  21     Uranus in Conjunction with Sun 
Apr 10  22:05  Aldebaran 0.4°S of Moon
Apr 14  03:59  FIRST QUARTER MOON 
Apr 17  00:46  Regulus 2.5°N of Moon
Apr 18  04:42  Jupiter 2.2°N of Moon
Apr 18  14     Mercury at Greatest Elongation: 19.9°E
Apr 18  18:04  Moon at Ascending Node 
Apr 21  07:59  Spica 5.1°S of Moon
Apr 21  16:05  Moon at Apogee: 406352 km
Apr 22  05:24  FULL MOON 
Apr 22  05     Lyrid Meteor Shower
Apr 25  04:13  Mars 4.9°S of Moon
Apr 25  19:28  Saturn 3.3°S of Moon
Apr 27  13:51  Mars 4.8°N of Antares
Apr 28  08:14  Mercury 3.0°S of Pleiades
Apr 30  03:29  LAST QUARTER 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



Events for March 2016

The following table gives the date and time of important astronomical events for March 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 March 2016
------  -----  --------------------------------------------
        (h:m)
Mar 01  23:11  LAST QUARTER MOON 
Mar 02  06:53  Saturn 3.6°S of Moon
Mar 07  10:54  Venus 3.5°S of Moon
Mar 08  10     Jupiter at Opposition 
Mar 09  01:54  NEW MOON 
Mar 09  01:57  Total Solar Eclipse; mag=1.045
Mar 09  06:31  Moon at Descending Node 
Mar 10  07:02  Moon at Perigee: 359509 km
Mar 14  13:44  Aldebaran 0.3°S of Moon
Mar 15  17:03  FIRST QUARTER MOON 
Mar 20  04:31  Vernal Equinox 
Mar 20  14     Venus at Aphelion 
Mar 20  19:05  Regulus 2.5°N of Moon
Mar 22  03:57  Jupiter 2.1°N of Moon
Mar 22  12:59  Moon at Ascending Node 
Mar 23  11:47  Penumbral Lunar Eclipse; mag=0.775
Mar 23  12:01  FULL MOON 
Mar 23  20     Mercury at Superior Conjunction 
Mar 25  01:50  Spica 5.1°S of Moon
Mar 25  14:16  Moon at Apogee: 406125 km
Mar 28  18:45  Mars 4.2°S of Moon
Mar 29  14:58  Saturn 3.5°S of Moon
Mar 31  15:17  LAST QUARTER 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



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.

					

Events for February 2016

The following table gives the date and time of important astronomical events for February 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 February 2016
------  -----  --------------------------------------------
        (h:m)
Feb 01  03:28  LAST QUARTER MOON 
Feb 01  08:48  Mars 2.7°S of Moon
Feb 03  19:05  Saturn 3.5°S of Moon
Feb 06  07:32  Venus 4.3°S of Moon
Feb 06  16:47  Mercury 3.8°S of Moon
Feb 07  01     Mercury at Greatest Elongation: 25.6°W
Feb 08  14:39  NEW MOON 
Feb 10  20:46  Moon at Descending Node 
Feb 11  02:42  Moon at Perigee: 364358 km
Feb 13  03     Mercury 4.0° of Venus
Feb 15  07:46  FIRST QUARTER MOON 
Feb 16  07:41  Aldebaran 0.3°S of Moon
Feb 21  17     Mercury at Aphelion 
Feb 22  12:48  Regulus 2.5°N of Moon
Feb 22  18:20  FULL MOON 
Feb 24  03:58  Jupiter 1.7°N of Moon
Feb 24  06:10  Moon at Ascending Node 
Feb 26  19:05  Spica 5.1°S of Moon
Feb 27  03:28  Moon at Apogee: 405383 km
Feb 28  15     Neptune in Conjunction with Sun 
Feb 29  18:16  Mars 3.6°S of 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



Events for January 2016

The following table gives the date and time of important astronomical events for
January 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 January 2016
------  -----  --------------------------------------------
        (h:m)
Jan 02  05:30  LAST QUARTER MOON 
Jan 02  11:53  Moon at Apogee: 404279 km
Jan 02  23     Earth at Perihelion: 0.98330 AU
Jan 03  03:35  Spica 4.7°S of Moon
Jan 03  18:45  Mars 1.5°S of Moon
Jan 04  08     Quadrantid Meteor Shower
Jan 06  23:57  Venus 3.1°S of Moon
Jan 07  04:57  Saturn 3.3°S of Moon
Jan 07  11:34  Venus 6.3°N of Antares
Jan 08  18     Mercury at Perihelion 
Jan 10  01:30  NEW MOON 
Jan 14  14     Mercury at Inferior Conjunction 
Jan 14  15:48  Moon at Descending Node 
Jan 15  02:10  Moon at Perigee: 369619 km
Jan 16  23:26  FIRST QUARTER MOON 
Jan 20  02:16  Aldebaran 0.5°S of Moon
Jan 24  01:46  FULL MOON 
Jan 26  05:10  Regulus 2.5°N of Moon
Jan 27  23:58  Moon at Ascending Node 
Jan 28  01:14  Jupiter 1.4°N of Moon
Jan 30  09:10  Moon at Apogee: 404553 km
Jan 30  11:35  Spica 5.0°S of 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



Moon in 2016

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.

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 2016.

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 2016 (GMT)

   New Moon      First Quarter      Full Moon       Last Quarter
-------------    -------------    -------------    -------------   
                                                   Jan  2  05:30    
Jan 10  01:31    Jan 16  23:26    Jan 24  01:46    Feb  1  03:28    
Feb  8  14:39    Feb 15  07:46    Feb 22  18:20    Mar  1  23:11    
Mar  9  01:54T   Mar 15  17:03    Mar 23  12:01n   Mar 31  15:17    
Apr  7  11:24    Apr 14  03:59    Apr 22  05:24    Apr 30  03:29    
May  6  19:30    May 13  17:02    May 21  21:15    May 29  12:12    
Jun  5  03:00    Jun 12  08:10    Jun 20  11:02    Jun 27  18:19    
Jul  4  11:01    Jul 12  00:52    Jul 19  22:57    Jul 26  23:00    
Aug  2  20:45    Aug 10  18:21    Aug 18  09:27    Aug 25  03:41    
Sep  1  09:03A   Sep  9  11:49    Sep 16  19:05n   Sep 23  09:56    
Oct  1  00:12    Oct  9  04:33    Oct 16  04:23    Oct 22  19:14    
Oct 30  17:38    Nov  7  19:51    Nov 14  13:52    Nov 21  08:33    
Nov 29  12:18    Dec  7  09:03    Dec 14  00:06    Dec 21  01:56    
Dec 29  06:53                                                          

The table above lists the date and time of the Moon’s phases throughout 2016. 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 on AstroPixels.com 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 2016. For instance, the fifth synodic month of 2016 (beginning May 06) is 5 hours 14 minutes shorter than the mean while the tenth month (beginning Oct 30) is 5 hours 56 minutes longer than the mean.

              Synodic Months for 2016 

   Date/Time of          Length of        Dif. from
  New Moon (GMT)       Synodic Month      Mean Month 
------------------     -------------     -----------
2016 Jan 10  01:31      29d 13h 08m       +00h 24m            
2016 Feb 08  14:39      29d 11h 16m       -01h 28m           
2016 Mar 09  01:54      29d 09h 29m       -03h 15m            
2016 Apr 07  11:24      29d 08h 06m       -04h 38m            
2016 May 06  19:29      29d 07h 30m       -05h 14m   shortest
2016 Jun 05  03:00      29d 08h 01m       -04h 43m            
2016 Jul 04  11:01      29d 09h 44m       -03h 01m            
2016 Aug 02  20:45      29d 12h 19m       -00h 25m            
2016 Sep 01  09:03      29d 15h 08m       +02h 24m            
2016 Oct 01  00:11      29d 17h 27m       +04h 43m            
2016 Oct 30  17:38      29d 18h 40m       +05h 56m   longest
2016 Nov 29  12:18      29d 18h 35m       +05h 51m            
2016 Dec 29  06:53      29d 17h 14m       +04h 30m            

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 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).

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. It averages 12.2° per day. A table giving the Moon’s daily celestial coordinates throughout the year can be found at Moon Ephemeris for 2016 (AstroPixels.com). 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 perigee-syzygy 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 Super Moons occurring in 2016.

              Super Moons for 2016

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

Sep 16  19:05 n   364754     32.76    0.934
Oct 16  04:23     358475     33.33    0.987
Nov 14  13:52     356523 m   33.52    1.000
Dec 14  00:06     359450     33.24    0.979

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

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.

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 image data from the Lunar Reconnaissance Orbiter (LRO) mission to create clever animations of the Moon’s ever changing phases and librations in 2016. The example below illustrates the Moon’s phase and libration at hourly intervals throughout 2016, 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 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 (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 2016 (see Moon Phase and Libration, 2016).

The last eclipse of the Moon visible from the USA occurred on the night of Sept. 27/28, 2015. It was a total eclipse as the Moon passed completely inside Earth's dark umbral shadow. ©2015 by Fred Espenak, MrEclipse.com.

The last eclipse of the Moon visible from the USA occurred on the night of Sept. 27/28, 2015. It was a total eclipse as the Moon passed completely inside Earth’s dark umbral shadow. ©2015 by Fred Espenak.

Finally, what discussion of the Moon would be complete without mentioning eclipses in 2016? There are two eclipses of the Moon and both of them are penumbral. The first occurs on March 23 and is visible from the western hemisphere. The second happens six months later on September 16 and is visible from the eastern hemisphere. Penumbral eclipses are very subtle events and often transpire without any notice (see: Visual Appearance of Penumbral Lunar Eclipses). But the 2016 eclipses are both deep penumbral eclipses so a pale shading should be visible around the time of mid-eclipse. By coincidence, the September 16 eclipse also happens to occur during a Super Moon.

Some sources identify a third penumbral eclipse on August 18. But this prediction depends on different assumptions about the size of Earth’s penumbral shadow. Even if you accept these assumptions, the eclipse barely occurs at all because only a scant 1.7% of the Moon’s diameter enters the penumbral shadow. For those who want to dig deeper into this subject, see: Enlargement of Earth’s Shadows. If such a small eclipse were to occur, it would be completely undetectable with even the largest telescopes on Earth.

There are also two solar eclipses in 2016. The first is a total eclipse on March 16 visible from Indonesia and parts of the Pacific Ocean. The second is an annular solar eclipse on September 01 visible from southern Africa and Madagascar. For complete details on all these events, see Eclipses During 2016 (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 and MacBook Pro) using Astronomical Algorithms (Jean Meeus).

Fred Espenak


Events for December 2015

The following table gives the date and time of important astronomical events for December 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 December 2015
------  -----  --------------------------------------------
        (h:m)
Dec 02  11:53  Regulus 3.0°N of Moon
Dec 03  07:40  LAST QUARTER MOON 
Dec 04  06:21  Jupiter 1.8°N of Moon
Dec 04  18:33  Moon at Ascending Node 
Dec 05  14:56  Moon at Apogee: 404800 km
Dec 06  02:40  Mars 0.1°N of Moon: Occultation
Dec 06  19:42  Spica 4.4°S of Moon
Dec 07  16:55  Venus 0.7°S of Moon: Occultation
Dec 11  10:29  NEW MOON 
Dec 14  18     Geminid Meteor Shower
Dec 18  06:01  Saturn 6.1°N of Antares
Dec 18  15:13  Moon at Descending Node 
Dec 18  15:14  FIRST QUARTER MOON 
Dec 21  08:53  Moon at Perigee: 368418 km
Dec 22  04:48  Winter Solstice 
Dec 23  02     Ursid Meteor Shower
Dec 23  14:18  Mars 3.3°N of Spica
Dec 23  19:09  Aldebaran 0.7°S of Moon
Dec 25  11:11  FULL MOON 
Dec 29  03     Mercury at Greatest Elongation: 19.7°E
Dec 29  20:30  Regulus 2.7°N of Moon
Dec 31  17:55  Jupiter 1.5°N of Moon
Dec 31  20:19  Moon at Ascending Node 

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 November 2015

The following table gives the date and time of important astronomical events for November 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 November 2015
------  -----  --------------------------------------------
        (h:m)
Nov 03  12:24  LAST QUARTER MOON 
Nov 05  04:19  Regulus 3.2°N of Moon
Nov 05  23     S Taurid Meteor Shower
Nov 06  15:49  Jupiter 2.3°N of Moon
Nov 07  09:56  Mars 1.8°N of Moon
Nov 07  13:54  Venus 1.2°N of Moon
Nov 07  15:53  Moon at Ascending Node 
Nov 07  21:48  Moon at Apogee: 405724 km
Nov 09  12:27  Spica 4.3°S of Moon
Nov 11  17:47  NEW MOON 
Nov 12  22     N Taurid Meteor Shower
Nov 17  15     Mercury at Superior Conjunction 
Nov 18  05     Leonid Meteor Shower
Nov 19  06:27  FIRST QUARTER MOON 
Nov 21  00     Mars at Aphelion 
Nov 21  13:56  Moon at Descending Node 
Nov 23  20:06  Moon at Perigee: 362818 km
Nov 25  22:44  FULL MOON 
Nov 26  09:33  Aldebaran 0.7°S of Moon
Nov 29  06     Venus at Perihelion 
Nov 29  19:20  Venus 3.9°N of Spica
Nov 30  00     Saturn 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