2011Calendar of Astronomical Events

    
2011Phases of the Moon
Atlantic Standard Time
The following table gives the date and time of the Moon's phases for the year. The times listed are for Atlantic Standard Time(Greenwich Mean Time - 4 hours).If Daylight Saving Time is in effect, add one hour to the times listed. 
   
      2011 Phases of the Moon   
      Atlantic Standard Time
 New Moon  First Quarter  Full Moon  Last Quarter 
 Jan  4  05:03 P  Jan 12  07:31    Jan 19  17:21    Jan 26  08:57   
 Feb  2  22:31    Feb 11  03:18    Feb 18  04:36    Feb 24  19:26   
 Mar  4  16:46    Mar 12  19:45    Mar 19  14:10    Mar 26  08:07   
 Apr  3  10:32    Apr 11  08:05    Apr 17  22:44    Apr 24  22:47   
 May  3  02:51    May 10  16:33    May 17  07:09    May 24  14:52   
 Jun  1  17:03 P  Jun  8  22:11    Jun 15  16:13 t  Jun 23  07:48   
 Jul  1  04:54 P  Jul  8  02:29    Jul 15  02:40    Jul 23  01:02   
 Jul 30  14:40    Aug  6  07:08    Aug 13  14:58    Aug 21  17:55   
 Aug 28  23:04    Sep  4  13:39    Sep 12  05:27    Sep 20  09:39   
 Sep 27  07:09    Oct  3  23:15    Oct 11  22:06    Oct 19  23:30   
 Oct 26  15:56    Nov  2  12:38    Nov 10  16:16    Nov 18  11:09   
 Nov 25  02:10 P  Dec  2  05:52    Dec 10  10:36 t  Dec 17  20:48   
 Dec 24  14:06   ---
An eclipse of the Sun can only occur at New Moon (see: Solar Eclipses for Beginners), while an eclipse of the Moon can only occur at Full Moon (see: Lunar Eclipses for Beginners). In any calendar year there are a minimum of two solar and two lunar eclipses.
If an eclipse of the Sun or Moon takes place on a given date, it is noted by a character next to the date in the table above. Solar eclipses are indicated as: T=Total, A=Annular, H=Hybrid and P=Partial.Lunar eclipses are indicated as: t=Total, p=Partial, and n=Penumbral. 
Phases of the Moon Photo Gallery is an image collection showing the Moon's phases over a complete synodic month.
2011Calendar of Astronomical Events
Atlantic Standard Time
The following table gives the date and time of the important astronomical events for the year. The times listed are for Atlantic Standard Time(Greenwich Mean Time - 4 hours).If Daylight Saving Time is in effect, add one hour to the times listed. A key to astronomical terms appears below the calendar.
   
      2011Calendar of Astronomical Events   
   Atlantic Standard Time  
 January - June   July - December 
Date     AST   Event        (h:m)Jan 01  14:07  Antares 2.5°S of Moon    02  10:32  Mercury 3.8°N of Moon    03  08:48  Moon at Ascending Node     03  15     Earth at Perihelion: 0.98334 AU    03  21     Quadrantid Meteor Shower    04  04:51  Partial Solar Eclipse; mag=0.858    04  05:03  NEW MOON     08  11     Venus at Greatest Elong: 47.0°W    09  10     Mercury at Greatest Elong: 23.3°W    10  01:38  Moon at Apogee: 404976 km    12  07:31  FIRST QUARTER MOON     15  08:39  Pleiades 1.3°N of Moon    17  20:06  Moon at Descending Node     19  17:21  FULL MOON     21  20:10  Moon at Perigee: 362793 km    21  21:55  Regulus 5.3°N of Moon    25  13:38  Spica 3.0°N of Moon    26  08:57  LAST QUARTER MOON     28  19:53  Antares 2.6°S of Moon    29  23:36  Venus 3.5°N of Moon    30  14:29  Moon at Ascending Node     31  05     Mercury at Aphelion Feb 01  14:14  Mercury 3.6°S of Moon    02  22:31  NEW MOON     04  13     Mars in Conjunction with Sun     06  19:13  Moon at Apogee: 405924 km    11  03:18  FIRST QUARTER MOON     11  17:32  Pleiades 1.4°N of Moon    14  04:14  Moon at Descending Node     17  05     Neptune in Conjunction with Sun     18  04:36  FULL MOON     18  08:18  Regulus 5.2°N of Moon    19  03:27  Moon at Perigee: 358247 km    21  21:02  Spica 2.8°N of Moon    24  19:26  LAST QUARTER MOON     25  01:26  Antares 2.8°S of Moon    25  04     Mercury at Superior Conjunction     26  16:19  Moon at Ascending Node     28  23:40  Venus 1.6°S of MoonMar 04  16:46  NEW MOON     06  03:50  Moon at Apogee: 406584 km    09  10     Mars at Perihelion:  1.38138 AU    11  00:35  Pleiades 1.7°N of Moon    12  19:45  FIRST QUARTER MOON     13  07:55  Moon at Descending Node     15  16     Mercury 2.0°N of Jupiter    16  04     Mercury at Perihelion     17  13     Jupiter at Perihelion:  4.94839 AU    17  19:35  Regulus 5.3°N of Moon    19  14:10  FULL MOON     19  15:09  Moon at Perigee: 356578 km    20  19:21  Vernal Equinox     21  07:00  Spica 2.6°N of Moon    21  08     Uranus in Conjunction with Sun     22  21     Mercury at Greatest Elong: 18.6°E    24  08:48  Antares 3.0°S of Moon    25  17:09  Moon at Ascending Node     26  08:07  LAST QUARTER MOON Apr 02  05:00  Moon at Apogee: 406656 km    03  10:32  NEW MOON     03  19     Saturn at Opposition     06  11     Jupiter in Conjunction with Sun     07  06:19  Pleiades 1.9°N of Moon    09  08:48  Moon at Descending Node     09  15     Mercury at Inferior Conjunction     11  08:05  FIRST QUARTER MOON     14  05:34  Regulus 5.5°N of Moon    17  01:59  Moon at Perigee: 358088 km    17  18:04  Spica 2.5°N of Moon    17  22:44  FULL MOON     18  20     Venus at Aphelion     19  14     Mercury 0.6°N of Mars    20  18:21  Antares 3.2°S of Moon    21  21:05  Moon at Ascending Node     22  19     Lyrid Meteor Shower    24  22:47  LAST QUARTER MOON     29  14:02  Moon at Apogee: 406043 kmMay 01  00     Mars 0.4°N of Jupiter    03  02:51  NEW MOON     05  08     Eta-Aquarid Meteor Shower    06  10:54  Moon at Descending Node     07  15     Mercury at Greatest Elong: 26.6°W    08  01     Mercury 1.4°S of Venus    10  16:33  FIRST QUARTER MOON     11  11     Venus 0.6°S of Jupiter    11  13:05  Regulus 5.7°N of Moon    11  16     Mercury 2.1°S of Jupiter    15  04:08  Spica 2.6°N of Moon    15  07:18  Moon at Perigee: 362133 km    17  07:09  FULL MOON     18  03     Mercury 1.4°S of Venus    18  04:46  Antares 3.3°S of Moon    19  05:03  Moon at Ascending Node     21  04     Mercury 2.1°S of Mars    23  05     Venus 1.0°S of Mars    24  14:52  LAST QUARTER MOON     27  05:58  Moon at Apogee: 405006 km    29  10:31  Jupiter 5.7°S of Moon    30  16:04  Mars 3.8°S of Moon    31  00:00  Venus 4.4°S of MoonJun 01  17:03  NEW MOON     01  17:16  Partial Solar Eclipse; mag=0.601    02  16:21  Moon at Descending Node     07  18:45  Regulus 5.7°N of Moon    08  22:11  FIRST QUARTER MOON     09  10:50  Venus 5.0°S of Pleiades    11  11:57  Spica 2.6°N of Moon    11  21:42  Moon at Perigee: 367188 km    12  04     Mercury at Perihelion     12  19     Mercury at Superior Conjunction     14  14:17  Antares 3.3°S of Moon    15  14:35  Moon at Ascending Node     15  16:13  Total Lunar Eclipse; mag=1.700    15  16:13  FULL MOON     17  08:15  Venus 4.6°N of Aldebaran    20  21:24  Mars 4.2°S of Pleiades    21  13:16  Summer Solstice     23  07:48  LAST QUARTER MOON     24  00:13  Moon at Apogee: 404275 km    26  04:45  Jupiter 5.4°S of Moon    28  02:52  Pleiades 2.0°N of Moon    28  03:40  Mercury 4.7°S of Pollux    28  14:59  Mars 1.7°S of Moon    30  00:14  Moon at Descending Node 
Date     AST   Event        (h:m)Jul 01  04:38  Partial Solar Eclipse; mag=0.097    01  04:54  NEW MOON     02  22:11  Mercury 5.1°N of Moon    04  11     Earth at Aphelion: 1.01674 AU    04  15:18  Mars 5.4°N of Aldebaran    05  00:23  Regulus 5.7°N of Moon    06  13:36  Mercury 0.2°S of Beehive    07  10:04  Moon at Perigee: 369566 km    08  02:29  FIRST QUARTER MOON     08  17:44  Spica 2.6°N of Moon    11  21:48  Antares 3.3°S of Moon    12  22:27  Moon at Ascending Node     15  02:40  FULL MOON     20  01     Mercury at Greatest Elong: 26.8°E    21  18:46  Moon at Apogee: 404358 km    23  01:02  LAST QUARTER MOON     23  20:34  Jupiter 5.1°S of Moon    25  11:28  Pleiades 2.1°N of Moon    26  03     Mercury at Aphelion     26  08:51  Mercury 2.1°S of Regulus    27  08:03  Moon at Descending Node     27  12:52  Mars 0.5°N of Moon: Occn.    28  10     Delta-Aquarid Meteor Shower    30  14:40  NEW MOON Aug 01  07:20  Mercury 1.5°N of Moon    01  07:41  Regulus 5.6°N of Moon    02  16:59  Moon at Perigee: 365756 km    04  23:08  Spica 2.4°N of Moon    06  07:08  FIRST QUARTER MOON     08  03:32  Antares 3.5°S of Moon    09  02:35  Moon at Ascending Node     09  04     Venus at Perihelion     13  02     Perseid Meteor Shower    13  14:58  FULL MOON     16  08     Venus at Superior Conjunction     16  21     Mercury at Inferior Conjunction     18  12:23  Moon at Apogee: 405161 km    20  08:13  Jupiter 4.8°S of Moon    21  17:55  LAST QUARTER MOON     21  19:40  Pleiades 2.3°N of Moon    22  18     Neptune at Opposition     23  13:23  Moon at Descending Node     25  09:36  Mars 2.7°N of Moon    27  21:07  Mercury 2.6°N of Moon    28  23:04  NEW MOON     30  13:35  Moon at Perigee: 360858 kmSep 01  06:06  Spica 2.2°N of Moon    03  02     Mercury at Greatest Elong: 18.1°W    04  09:00  Antares 3.7°S of Moon    04  13:39  FIRST QUARTER MOON     05  03:36  Moon at Ascending Node     08  03     Mercury at Perihelion     08  04:45  Mars 5.8°S of Pollux    08  22:18  Mercury 0.6°N of Regulus    12  05:27  FULL MOON     15  02:23  Moon at Apogee: 406068 km    16  14:20  Jupiter 4.7°S of Moon    18  02:46  Pleiades 2.5°N of Moon    19  15:38  Moon at Descending Node     20  09:39  LAST QUARTER MOON     23  04:23  Mars 4.8°N of Moon    23  05:05  Autumnal Equinox     25  03:49  Regulus 5.7°N of Moon    25  20     Uranus at Opposition     27  07:09  NEW MOON     27  21:01  Moon at Perigee: 357556 km    28  16     Mercury at Superior Conjunction     29  23     Venus 1.3°S of Saturn    30  20:53  Mars 0.4°S of BeehiveOct 01  16:04  Antares 3.9°S of Moon    02  05:09  Moon at Ascending Node     03  23:15  FIRST QUARTER MOON     11  22:06  FULL MOON     12  07:43  Moon at Apogee: 406435 km    13  15:28  Jupiter 4.8°S of Moon    13  17     Saturn in Conjunction with Sun     15  08:49  Pleiades 2.7°N of Moon    16  17:01  Moon at Descending Node     19  23:30  LAST QUARTER MOON     21  18     Orionid Meteor Shower    22  13:52  Regulus 5.8°N of Moon    26  08:26  Moon at Perigee: 357051 km    26  15:56  NEW MOON     27  22:14  Mercury 0.2°N of Moon: Occn.    28  01:11  Venus 1.8°N of Moon    28  21     Jupiter at Opposition     29  01:37  Antares 4.1°S of Moon    29  10:59  Moon at Ascending Node Nov 01  16     Mercury 2.0°S of Venus    02  12:38  FIRST QUARTER MOON     05  18     S Taurid Meteor Shower    08  09:20  Moon at Apogee: 406177 km    09  14:40  Jupiter 5.0°S of Moon    10  03:51  Venus 3.8°N of Antares    10  04:27  Mercury 1.9°N of Antares    10  14:21  Mars 1.3°N of Regulus    10  16:16  FULL MOON     11  07:32  Saturn 4.0°N of Spica    11  14:43  Pleiades 2.8°N of Moon    12  13:18  Aldebaran 5.9°S of Moon    12  18     N Taurid Meteor Shower    12  20:35  Moon at Descending Node     13  04     Mercury 2.0°S of Venus    14  05     Mercury at Greatest Elong: 22.7°E    18  00     Leonid Meteor Shower    18  11:09  LAST QUARTER MOON     18  21:42  Regulus 6.0°N of Moon    22  13:21  Spica 2.1°N of Moon    23  19:24  Moon at Perigee: 359692 km    25  02:10  NEW MOON     25  02:20  Partial Solar Eclipse; mag=0.905    25  21:02  Moon at Ascending Node     26  05:48  Mercury 1.7°S of Moon    27  00:29  Venus 2.8°S of MoonDec 02  05:52  FIRST QUARTER MOON     04  05     Mercury at Inferior Conjunction     05  02     Mercury at Perihelion     05  21:13  Moon at Apogee: 405414 km    06  16:10  Jupiter 5.2°S of Moon    08  21:26  Pleiades 2.8°N of Moon    09  19:51  Aldebaran 5.9°S of Moon    10  03:04  Moon at Descending Node     10  10:32  Total Lunar Eclipse; mag=1.106    10  10:36  FULL MOON     14  13     Geminid Meteor Shower    16  03:26  Regulus 6.0°N of Moon    17  20:48  LAST QUARTER MOON     19  21:37  Spica 2.1°N of Moon    21  22:56  Moon at Perigee: 364801 km    22  01:30  Winter Solstice     22  22     Ursid Meteor Shower    22  23     Mercury at Greatest Elong: 21.8°W    22  23:05  Antares 4.1°S of Moon    22  23:50  Mercury 2.6°N of Moon    23  07:36  Moon at Ascending Node     24  06:36  Mercury 6.3°N of Antares    24  14:06  NEW MOON     

 Terms Used in Astronomical Events Calendar 
  • Perihelion - instant when a planet is closest to the Sun
  • Aphelion - instant when a planet is furthest from the Sun
  • Perigee - instant when the Moon is closest to Earth
  • Apogee - instant when the Moon is furthest from Earth
  • Inferior Conjunction - instant when a planet (Mercury or Venus) passes between Earth and the Sun
  • Superior Conjunction - instant when a planet (Mercury or Venus) passes on the opposite side of the Sun from Earth 
  • Greatest Elongation - the maximum angular separation between the Sun and the planet (Mercury or Venus) as seen from Earth 
     - during eastern elongation (E), the planet appears as an evening star; 
     - during western elongation (W), the planet appears as a morning star
  • Opposition - instant when a planet appears opposite the Sun as seen from Earth
  • Conjunction - instant when a planet appears closest the Sun as seen from Earth
  • Occultation - the Moon occults or eclipses a star or planet
  • Ascending Node - point where the Moon crosses from the southern to northern portion of its orbit
  • Descending Node - point where the Moon crosses from the northern to the southern portion of its orbit

  • Aldebaran - bright star in the constellation Taurus
  • Pollux - bright star in the constellation Gemini
  • Regulus - bright star in the constellation Leo
  • Spica - bright star in the constellation Virgo
  • Antares - bright star in the constellation Scorpius
  • Pleiades - bright star cluster in the constellation Taurus
  • Beehive - bright star cluster in the constellation Cancer
Calendars of Astronomical Events: 2011 to 2020
The Americas
Below are links to calendars of astronomical events from 2011 to 2020 for seven time zones in the Americas. 
Choose a time zone and click on a year to get a calendar of astronomical events for that year.
   Calendars of Astronomical Events - The Americas
   AST    2011     2012     2013     2014     2015     2016     2017     2018     2019     2020 
   EST    2011     2012     2013     2014     2015     2016     2017     2018     2019     2020 
   CST    2011     2012     2013     2014     2015     2016     2017     2018     2019     2020 
   MST    2011     2012     2013     2014     2015     2016     2017     2018     2019     2020 
   PST    2011     2012     2013     2014     2015     2016     2017     2018     2019     2020 
   AKST    2011     2012     2013     2014     2015     2016     2017     2018     2019     2020 
   HST    2011     2012     2013     2014     2015     2016     2017     2018     2019     2020 
        Time Zones Abbreviations
        • AST = Atlantic Standard Time (= GMT - 4 hours)
        • EST = Eastern Standard Time (= GMT - 5 hours)
        • CST = Central Standard Time (= GMT - 6 hours)
        • MST = Mountain Standard Time (= GMT - 7 hours)
        • PST = Pacific Standard Time (= GMT - 8 hours)
        • AKST = Alaskan Standard Time (= GMT - 9 hours)
        • HST = Hawaiian Standard Time (= GMT - 10 hours)
           (where GMT = Greenwich Mean Time)
A time zone may have a different name in different countries. Note the difference in hours between a given time zone and Greenwich Mean Time to help in identification.
For other years and other time zones, visit: Calendars of Astronomical Events.
 
Accuracy of the Astronomical Events Calendars
The goal of the Astronomical Events Calendars is to present a wide range of solar system phenomena with reasonable accuracy. In general, events listed to the nearest hour are accurate to ± 30 minutes.Events listed with a precision in hours and minutes (i.e., hh:mm) are typically accurate to ± 5 minutes or less.  
The following table gives a more detailed breakdown of the accuracy of times for various astronomical events.
Accuracy of the Astronomical Events Calendars
 Solstice/Equinox (Earth)  ± 0.5 minute 
 Aphelion/Perihelion (Earth)  ± 30 minutes;  ± 0.00001 AU 
 Solar and Lunar Eclipses   ± 0.5 minute 
 Phases of the Moon  ± 0.5 minute 
 Moon at Nodes  ± 2 minutes 
 Apogee/Perigee of Moon  ± 5 minutes; ± 5 kilometers 
 Conjunctions of Moon with Star or Planet  ± 10 minutes 
 Conjunctions of Planet with Planet  ± 3 hours 
 Inferior/Superior Conjunctions (Mercury & Venus)  ± 30 minutes 
 Greatest Elongation (Mercury & Venus)  ± 30 minutes 
 Opposition/Conjunction (Outer Planets)  ± 3 hours 
 Aphelion/Perihelion of Planets  ± 30 minutes 

Acknowledgements
All calculations are by Fred Espenak and he assumes full responsibility for their accuracy. Algorithms used in predicting many of the astronomical events are based on Astronomical Algorithms by Jean Meeus (Willmann-Bell Inc. Richmond 1998). 
Permission is freely granted to reproduce this data when accompanied by the acknowledgment: 

Return to: Calendars of Astronomical Events
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