2011Calendar of Astronomical Events

    
2011Phases of the Moon
Eastern Standard Time
The following table gives the date and time of the Moon's phases for the year. The times listed are for Eastern Standard Time(Greenwich Mean Time - 5 hours).If Daylight Saving Time is in effect, add one hour to the times listed. 
   
      2011 Phases of the Moon   
      Eastern Standard Time
 New Moon  First Quarter  Full Moon  Last Quarter 
 Jan  4  04:03 P  Jan 12  06:31    Jan 19  16:21    Jan 26  07:57   
 Feb  2  21:31    Feb 11  02:18    Feb 18  03:36    Feb 24  18:26   
 Mar  4  15:46    Mar 12  18:45    Mar 19  13:10    Mar 26  07:07   
 Apr  3  09:32    Apr 11  07:05    Apr 17  21:44    Apr 24  21:47   
 May  3  01:51    May 10  15:33    May 17  06:09    May 24  13:52   
 Jun  1  16:03 P  Jun  8  21:11    Jun 15  15:13 t  Jun 23  06:48   
 Jul  1  03:54 P  Jul  8  01:29    Jul 15  01:40    Jul 23  00:02   
 Jul 30  13:40    Aug  6  06:08    Aug 13  13:58    Aug 21  16:55   
 Aug 28  22:04    Sep  4  12:39    Sep 12  04:27    Sep 20  08:39   
 Sep 27  06:09    Oct  3  22:15    Oct 11  21:06    Oct 19  22:30   
 Oct 26  14:56    Nov  2  11:38    Nov 10  15:16    Nov 18  10:09   
 Nov 25  01:10 P  Dec  2  04:52    Dec 10  09:36 t  Dec 17  19:48   
 Dec 24  13:06   ---
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
Eastern Standard Time
The following table gives the date and time of the important astronomical events for the year. The times listed are for Eastern Standard Time(Greenwich Mean Time - 5 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   
   Eastern Standard Time  
 January - June   July - December 
Date     EST   Event        (h:m)Jan 01  13:07  Antares 2.5°S of Moon    02  09:32  Mercury 3.8°N of Moon    03  07:48  Moon at Ascending Node     03  14     Earth at Perihelion: 0.98334 AU    03  20     Quadrantid Meteor Shower    04  03:51  Partial Solar Eclipse; mag=0.858    04  04:03  NEW MOON     08  10     Venus at Greatest Elong: 47.0°W    09  09     Mercury at Greatest Elong: 23.3°W    10  00:38  Moon at Apogee: 404976 km    12  06:31  FIRST QUARTER MOON     15  07:39  Pleiades 1.3°N of Moon    17  19:06  Moon at Descending Node     19  16:21  FULL MOON     21  19:10  Moon at Perigee: 362793 km    21  20:55  Regulus 5.3°N of Moon    25  12:38  Spica 3.0°N of Moon    26  07:57  LAST QUARTER MOON     28  18:53  Antares 2.6°S of Moon    29  22:36  Venus 3.5°N of Moon    30  13:29  Moon at Ascending Node     31  04     Mercury at Aphelion Feb 01  13:14  Mercury 3.6°S of Moon    02  21:31  NEW MOON     04  12     Mars in Conjunction with Sun     06  18:13  Moon at Apogee: 405924 km    11  02:18  FIRST QUARTER MOON     11  16:32  Pleiades 1.4°N of Moon    14  03:14  Moon at Descending Node     17  04     Neptune in Conjunction with Sun     18  03:36  FULL MOON     18  07:18  Regulus 5.2°N of Moon    19  02:27  Moon at Perigee: 358247 km    21  20:02  Spica 2.8°N of Moon    24  18:26  LAST QUARTER MOON     25  00:26  Antares 2.8°S of Moon    25  03     Mercury at Superior Conjunction     26  15:19  Moon at Ascending Node     28  22:40  Venus 1.6°S of MoonMar 04  15:46  NEW MOON     06  02:50  Moon at Apogee: 406584 km    09  09     Mars at Perihelion:  1.38138 AU    10  23:35  Pleiades 1.7°N of Moon    12  18:45  FIRST QUARTER MOON     13  06:55  Moon at Descending Node     15  15     Mercury 2.0°N of Jupiter    16  03     Mercury at Perihelion     17  12     Jupiter at Perihelion:  4.94839 AU    17  18:35  Regulus 5.3°N of Moon    19  13:10  FULL MOON     19  14:09  Moon at Perigee: 356578 km    20  18:21  Vernal Equinox     21  06:00  Spica 2.6°N of Moon    21  07     Uranus in Conjunction with Sun     22  20     Mercury at Greatest Elong: 18.6°E    24  07:48  Antares 3.0°S of Moon    25  16:09  Moon at Ascending Node     26  07:07  LAST QUARTER MOON Apr 02  04:00  Moon at Apogee: 406656 km    03  09:32  NEW MOON     03  18     Saturn at Opposition     06  10     Jupiter in Conjunction with Sun     07  05:19  Pleiades 1.9°N of Moon    09  07:48  Moon at Descending Node     09  14     Mercury at Inferior Conjunction     11  07:05  FIRST QUARTER MOON     14  04:34  Regulus 5.5°N of Moon    17  00:59  Moon at Perigee: 358088 km    17  17:04  Spica 2.5°N of Moon    17  21:44  FULL MOON     18  19     Venus at Aphelion     19  13     Mercury 0.6°N of Mars    20  17:21  Antares 3.2°S of Moon    21  20:05  Moon at Ascending Node     22  18     Lyrid Meteor Shower    24  21:47  LAST QUARTER MOON     29  13:02  Moon at Apogee: 406043 km    30  23     Mars 0.4°N of JupiterMay 03  01:51  NEW MOON     05  07     Eta-Aquarid Meteor Shower    06  09:54  Moon at Descending Node     07  14     Mercury at Greatest Elong: 26.6°W    08  00     Mercury 1.4°S of Venus    10  15:33  FIRST QUARTER MOON     11  10     Venus 0.6°S of Jupiter    11  12:05  Regulus 5.7°N of Moon    11  15     Mercury 2.1°S of Jupiter    15  03:08  Spica 2.6°N of Moon    15  06:18  Moon at Perigee: 362133 km    17  06:09  FULL MOON     18  02     Mercury 1.4°S of Venus    18  03:46  Antares 3.3°S of Moon    19  04:03  Moon at Ascending Node     21  03     Mercury 2.1°S of Mars    23  04     Venus 1.0°S of Mars    24  13:52  LAST QUARTER MOON     27  04:58  Moon at Apogee: 405006 km    29  09:31  Jupiter 5.7°S of Moon    30  15:04  Mars 3.8°S of Moon    30  23:00  Venus 4.4°S of MoonJun 01  16:03  NEW MOON     01  16:16  Partial Solar Eclipse; mag=0.601    02  15:21  Moon at Descending Node     07  17:45  Regulus 5.7°N of Moon    08  21:11  FIRST QUARTER MOON     09  09:50  Venus 5.0°S of Pleiades    11  10:57  Spica 2.6°N of Moon    11  20:42  Moon at Perigee: 367188 km    12  03     Mercury at Perihelion     12  18     Mercury at Superior Conjunction     14  13:17  Antares 3.3°S of Moon    15  13:35  Moon at Ascending Node     15  15:13  Total Lunar Eclipse; mag=1.700    15  15:13  FULL MOON     17  07:15  Venus 4.6°N of Aldebaran    20  20:24  Mars 4.2°S of Pleiades    21  12:16  Summer Solstice     23  06:48  LAST QUARTER MOON     23  23:13  Moon at Apogee: 404275 km    26  03:45  Jupiter 5.4°S of Moon    28  01:52  Pleiades 2.0°N of Moon    28  02:40  Mercury 4.7°S of Pollux    28  13:59  Mars 1.7°S of Moon    29  23:14  Moon at Descending Node 
Date     EST   Event        (h:m)Jul 01  03:38  Partial Solar Eclipse; mag=0.097    01  03:54  NEW MOON     02  21:11  Mercury 5.1°N of Moon    04  10     Earth at Aphelion: 1.01674 AU    04  14:18  Mars 5.4°N of Aldebaran    04  23:23  Regulus 5.7°N of Moon    06  12:36  Mercury 0.2°S of Beehive    07  09:04  Moon at Perigee: 369566 km    08  01:29  FIRST QUARTER MOON     08  16:44  Spica 2.6°N of Moon    11  20:48  Antares 3.3°S of Moon    12  21:27  Moon at Ascending Node     15  01:40  FULL MOON     20  00     Mercury at Greatest Elong: 26.8°E    21  17:46  Moon at Apogee: 404358 km    23  00:02  LAST QUARTER MOON     23  19:34  Jupiter 5.1°S of Moon    25  10:28  Pleiades 2.1°N of Moon    26  02     Mercury at Aphelion     26  07:51  Mercury 2.1°S of Regulus    27  07:03  Moon at Descending Node     27  11:52  Mars 0.5°N of Moon: Occn.    28  09     Delta-Aquarid Meteor Shower    30  13:40  NEW MOON Aug 01  06:20  Mercury 1.5°N of Moon    01  06:41  Regulus 5.6°N of Moon    02  15:59  Moon at Perigee: 365756 km    04  22:08  Spica 2.4°N of Moon    06  06:08  FIRST QUARTER MOON     08  02:32  Antares 3.5°S of Moon    09  01:35  Moon at Ascending Node     09  03     Venus at Perihelion     13  01     Perseid Meteor Shower    13  13:58  FULL MOON     16  07     Venus at Superior Conjunction     16  20     Mercury at Inferior Conjunction     18  11:23  Moon at Apogee: 405161 km    20  07:13  Jupiter 4.8°S of Moon    21  16:55  LAST QUARTER MOON     21  18:40  Pleiades 2.3°N of Moon    22  17     Neptune at Opposition     23  12:23  Moon at Descending Node     25  08:36  Mars 2.7°N of Moon    27  20:07  Mercury 2.6°N of Moon    28  22:04  NEW MOON     30  12:35  Moon at Perigee: 360858 kmSep 01  05:06  Spica 2.2°N of Moon    03  01     Mercury at Greatest Elong: 18.1°W    04  08:00  Antares 3.7°S of Moon    04  12:39  FIRST QUARTER MOON     05  02:36  Moon at Ascending Node     08  02     Mercury at Perihelion     08  03:45  Mars 5.8°S of Pollux    08  21:18  Mercury 0.6°N of Regulus    12  04:27  FULL MOON     15  01:23  Moon at Apogee: 406068 km    16  13:20  Jupiter 4.7°S of Moon    18  01:46  Pleiades 2.5°N of Moon    19  14:38  Moon at Descending Node     20  08:39  LAST QUARTER MOON     23  03:23  Mars 4.8°N of Moon    23  04:05  Autumnal Equinox     25  02:49  Regulus 5.7°N of Moon    25  19     Uranus at Opposition     27  06:09  NEW MOON     27  20:01  Moon at Perigee: 357556 km    28  15     Mercury at Superior Conjunction     29  22     Venus 1.3°S of Saturn    30  19:53  Mars 0.4°S of BeehiveOct 01  15:04  Antares 3.9°S of Moon    02  04:09  Moon at Ascending Node     03  22:15  FIRST QUARTER MOON     11  21:06  FULL MOON     12  06:43  Moon at Apogee: 406435 km    13  14:28  Jupiter 4.8°S of Moon    13  16     Saturn in Conjunction with Sun     15  07:49  Pleiades 2.7°N of Moon    16  16:01  Moon at Descending Node     19  22:30  LAST QUARTER MOON     21  17     Orionid Meteor Shower    22  12:52  Regulus 5.8°N of Moon    26  07:26  Moon at Perigee: 357051 km    26  14:56  NEW MOON     27  21:14  Mercury 0.2°N of Moon: Occn.    28  00:11  Venus 1.8°N of Moon    28  20     Jupiter at Opposition     29  00:37  Antares 4.1°S of Moon    29  09:59  Moon at Ascending Node Nov 01  15     Mercury 2.0°S of Venus    02  11:38  FIRST QUARTER MOON     05  17     S Taurid Meteor Shower    08  08:20  Moon at Apogee: 406177 km    09  13:40  Jupiter 5.0°S of Moon    10  02:51  Venus 3.8°N of Antares    10  03:27  Mercury 1.9°N of Antares    10  13:21  Mars 1.3°N of Regulus    10  15:16  FULL MOON     11  06:32  Saturn 4.0°N of Spica    11  13:43  Pleiades 2.8°N of Moon    12  12:18  Aldebaran 5.9°S of Moon    12  17     N Taurid Meteor Shower    12  19:35  Moon at Descending Node     13  03     Mercury 2.0°S of Venus    14  04     Mercury at Greatest Elong: 22.7°E    17  23     Leonid Meteor Shower    18  10:09  LAST QUARTER MOON     18  20:42  Regulus 6.0°N of Moon    22  12:21  Spica 2.1°N of Moon    23  18:24  Moon at Perigee: 359692 km    25  01:10  NEW MOON     25  01:20  Partial Solar Eclipse; mag=0.905    25  20:02  Moon at Ascending Node     26  04:48  Mercury 1.7°S of Moon    26  23:29  Venus 2.8°S of MoonDec 02  04:52  FIRST QUARTER MOON     04  04     Mercury at Inferior Conjunction     05  01     Mercury at Perihelion     05  20:13  Moon at Apogee: 405414 km    06  15:10  Jupiter 5.2°S of Moon    08  20:26  Pleiades 2.8°N of Moon    09  18:51  Aldebaran 5.9°S of Moon    10  02:04  Moon at Descending Node     10  09:32  Total Lunar Eclipse; mag=1.106    10  09:36  FULL MOON     14  12     Geminid Meteor Shower    16  02:26  Regulus 6.0°N of Moon    17  19:48  LAST QUARTER MOON     19  20:37  Spica 2.1°N of Moon    21  21:56  Moon at Perigee: 364801 km    22  00:30  Winter Solstice     22  21     Ursid Meteor Shower    22  22     Mercury at Greatest Elong: 21.8°W    22  22:05  Antares 4.1°S of Moon    22  22:50  Mercury 2.6°N of Moon    23  06:36  Moon at Ascending Node     24  05:36  Mercury 6.3°N of Antares    24  13:06  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: 

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