2011Calendar of Astronomical Events

    
2011Phases of the Moon
Mountain Standard Time
The following table gives the date and time of the Moon's phases for the year. The times listed are for Mountain Standard Time(Greenwich Mean Time - 7 hours).If Daylight Saving Time is in effect, add one hour to the times listed. 
   
      2011 Phases of the Moon   
      Mountain Standard Time
 New Moon  First Quarter  Full Moon  Last Quarter 
 Jan  4  02:03 P  Jan 12  04:31    Jan 19  14:21    Jan 26  05:57   
 Feb  2  19:31    Feb 11  00:18    Feb 18  01:36    Feb 24  16:26   
 Mar  4  13:46    Mar 12  16:45    Mar 19  11:10    Mar 26  05:07   
 Apr  3  07:32    Apr 11  05:05    Apr 17  19:44    Apr 24  19:47   
 May  2  23:51    May 10  13:33    May 17  04:09    May 24  11:52   
 Jun  1  14:03 P  Jun  8  19:11    Jun 15  13:13 t  Jun 23  04:48   
 Jul  1  01:54 P  Jul  7  23:29    Jul 14  23:40    Jul 22  22:02   
 Jul 30  11:40    Aug  6  04:08    Aug 13  11:58    Aug 21  14:55   
 Aug 28  20:04    Sep  4  10:39    Sep 12  02:27    Sep 20  06:39   
 Sep 27  04:09    Oct  3  20:15    Oct 11  19:06    Oct 19  20:30   
 Oct 26  12:56    Nov  2  09:38    Nov 10  13:16    Nov 18  08:09   
 Nov 24  23:10 P  Dec  2  02:52    Dec 10  07:36 t  Dec 17  17:48   
 Dec 24  11:06   ---
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
Mountain Standard Time
The following table gives the date and time of the important astronomical events for the year. The times listed are for Mountain Standard Time(Greenwich Mean Time - 7 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   
   Mountain Standard Time  
 January - June   July - December 
Date     MST   Event        (h:m)Jan 01  11:07  Antares 2.5°S of Moon    02  07:32  Mercury 3.8°N of Moon    03  05:48  Moon at Ascending Node     03  12     Earth at Perihelion: 0.98334 AU    03  18     Quadrantid Meteor Shower    04  01:51  Partial Solar Eclipse; mag=0.858    04  02:03  NEW MOON     08  08     Venus at Greatest Elong: 47.0°W    09  07     Mercury at Greatest Elong: 23.3°W    09  22:38  Moon at Apogee: 404976 km    12  04:31  FIRST QUARTER MOON     15  05:39  Pleiades 1.3°N of Moon    17  17:06  Moon at Descending Node     19  14:21  FULL MOON     21  17:10  Moon at Perigee: 362793 km    21  18:55  Regulus 5.3°N of Moon    25  10:38  Spica 3.0°N of Moon    26  05:57  LAST QUARTER MOON     28  16:53  Antares 2.6°S of Moon    29  20:36  Venus 3.5°N of Moon    30  11:29  Moon at Ascending Node     31  02     Mercury at Aphelion Feb 01  11:14  Mercury 3.6°S of Moon    02  19:31  NEW MOON     04  10     Mars in Conjunction with Sun     06  16:13  Moon at Apogee: 405924 km    11  00:18  FIRST QUARTER MOON     11  14:32  Pleiades 1.4°N of Moon    14  01:14  Moon at Descending Node     17  02     Neptune in Conjunction with Sun     18  01:36  FULL MOON     18  05:18  Regulus 5.2°N of Moon    19  00:27  Moon at Perigee: 358247 km    21  18:02  Spica 2.8°N of Moon    24  16:26  LAST QUARTER MOON     24  22:26  Antares 2.8°S of Moon    25  01     Mercury at Superior Conjunction     26  13:19  Moon at Ascending Node     28  20:40  Venus 1.6°S of MoonMar 04  13:46  NEW MOON     06  00:50  Moon at Apogee: 406584 km    09  07     Mars at Perihelion:  1.38138 AU    10  21:35  Pleiades 1.7°N of Moon    12  16:45  FIRST QUARTER MOON     13  04:55  Moon at Descending Node     15  13     Mercury 2.0°N of Jupiter    16  01     Mercury at Perihelion     17  10     Jupiter at Perihelion:  4.94839 AU    17  16:35  Regulus 5.3°N of Moon    19  11:10  FULL MOON     19  12:09  Moon at Perigee: 356578 km    20  16:21  Vernal Equinox     21  04:00  Spica 2.6°N of Moon    21  05     Uranus in Conjunction with Sun     22  18     Mercury at Greatest Elong: 18.6°E    24  05:48  Antares 3.0°S of Moon    25  14:09  Moon at Ascending Node     26  05:07  LAST QUARTER MOON Apr 02  02:00  Moon at Apogee: 406656 km    03  07:32  NEW MOON     03  16     Saturn at Opposition     06  08     Jupiter in Conjunction with Sun     07  03:19  Pleiades 1.9°N of Moon    09  05:48  Moon at Descending Node     09  12     Mercury at Inferior Conjunction     11  05:05  FIRST QUARTER MOON     14  02:34  Regulus 5.5°N of Moon    16  22:59  Moon at Perigee: 358088 km    17  15:04  Spica 2.5°N of Moon    17  19:44  FULL MOON     18  17     Venus at Aphelion     19  11     Mercury 0.6°N of Mars    20  15:21  Antares 3.2°S of Moon    21  18:05  Moon at Ascending Node     22  16     Lyrid Meteor Shower    24  19:47  LAST QUARTER MOON     29  11:02  Moon at Apogee: 406043 km    30  21     Mars 0.4°N of JupiterMay 02  23:51  NEW MOON     05  05     Eta-Aquarid Meteor Shower    06  07:54  Moon at Descending Node     07  12     Mercury at Greatest Elong: 26.6°W    07  22     Mercury 1.4°S of Venus    10  13:33  FIRST QUARTER MOON     11  08     Venus 0.6°S of Jupiter    11  10:05  Regulus 5.7°N of Moon    11  13     Mercury 2.1°S of Jupiter    15  01:08  Spica 2.6°N of Moon    15  04:18  Moon at Perigee: 362133 km    17  04:09  FULL MOON     18  00     Mercury 1.4°S of Venus    18  01:46  Antares 3.3°S of Moon    19  02:03  Moon at Ascending Node     21  01     Mercury 2.1°S of Mars    23  02     Venus 1.0°S of Mars    24  11:52  LAST QUARTER MOON     27  02:58  Moon at Apogee: 405006 km    29  07:31  Jupiter 5.7°S of Moon    30  13:04  Mars 3.8°S of Moon    30  21:00  Venus 4.4°S of MoonJun 01  14:03  NEW MOON     01  14:16  Partial Solar Eclipse; mag=0.601    02  13:21  Moon at Descending Node     07  15:45  Regulus 5.7°N of Moon    08  19:11  FIRST QUARTER MOON     09  07:50  Venus 5.0°S of Pleiades    11  08:57  Spica 2.6°N of Moon    11  18:42  Moon at Perigee: 367188 km    12  01     Mercury at Perihelion     12  16     Mercury at Superior Conjunction     14  11:17  Antares 3.3°S of Moon    15  11:35  Moon at Ascending Node     15  13:13  Total Lunar Eclipse; mag=1.700    15  13:13  FULL MOON     17  05:15  Venus 4.6°N of Aldebaran    20  18:24  Mars 4.2°S of Pleiades    21  10:16  Summer Solstice     23  04:48  LAST QUARTER MOON     23  21:13  Moon at Apogee: 404275 km    26  01:45  Jupiter 5.4°S of Moon    27  23:52  Pleiades 2.0°N of Moon    28  00:40  Mercury 4.7°S of Pollux    28  11:59  Mars 1.7°S of Moon    29  21:14  Moon at Descending Node 
Date     MST   Event        (h:m)Jul 01  01:38  Partial Solar Eclipse; mag=0.097    01  01:54  NEW MOON     02  19:11  Mercury 5.1°N of Moon    04  08     Earth at Aphelion: 1.01674 AU    04  12:18  Mars 5.4°N of Aldebaran    04  21:23  Regulus 5.7°N of Moon    06  10:36  Mercury 0.2°S of Beehive    07  07:04  Moon at Perigee: 369566 km    07  23:29  FIRST QUARTER MOON     08  14:44  Spica 2.6°N of Moon    11  18:48  Antares 3.3°S of Moon    12  19:27  Moon at Ascending Node     14  23:40  FULL MOON     19  22     Mercury at Greatest Elong: 26.8°E    21  15:46  Moon at Apogee: 404358 km    22  22:02  LAST QUARTER MOON     23  17:34  Jupiter 5.1°S of Moon    25  08:28  Pleiades 2.1°N of Moon    26  00     Mercury at Aphelion     26  05:51  Mercury 2.1°S of Regulus    27  05:03  Moon at Descending Node     27  09:52  Mars 0.5°N of Moon: Occn.    28  07     Delta-Aquarid Meteor Shower    30  11:40  NEW MOON Aug 01  04:20  Mercury 1.5°N of Moon    01  04:41  Regulus 5.6°N of Moon    02  13:59  Moon at Perigee: 365756 km    04  20:08  Spica 2.4°N of Moon    06  04:08  FIRST QUARTER MOON     08  00:32  Antares 3.5°S of Moon    08  23:35  Moon at Ascending Node     09  01     Venus at Perihelion     12  23     Perseid Meteor Shower    13  11:58  FULL MOON     16  05     Venus at Superior Conjunction     16  18     Mercury at Inferior Conjunction     18  09:23  Moon at Apogee: 405161 km    20  05:13  Jupiter 4.8°S of Moon    21  14:55  LAST QUARTER MOON     21  16:40  Pleiades 2.3°N of Moon    22  15     Neptune at Opposition     23  10:23  Moon at Descending Node     25  06:36  Mars 2.7°N of Moon    27  18:07  Mercury 2.6°N of Moon    28  20:04  NEW MOON     30  10:35  Moon at Perigee: 360858 kmSep 01  03:06  Spica 2.2°N of Moon    02  23     Mercury at Greatest Elong: 18.1°W    04  06:00  Antares 3.7°S of Moon    04  10:39  FIRST QUARTER MOON     05  00:36  Moon at Ascending Node     08  00     Mercury at Perihelion     08  01:45  Mars 5.8°S of Pollux    08  19:18  Mercury 0.6°N of Regulus    12  02:27  FULL MOON     14  23:23  Moon at Apogee: 406068 km    16  11:20  Jupiter 4.7°S of Moon    17  23:46  Pleiades 2.5°N of Moon    19  12:38  Moon at Descending Node     20  06:39  LAST QUARTER MOON     23  01:23  Mars 4.8°N of Moon    23  02:05  Autumnal Equinox     25  00:49  Regulus 5.7°N of Moon    25  17     Uranus at Opposition     27  04:09  NEW MOON     27  18:01  Moon at Perigee: 357556 km    28  13     Mercury at Superior Conjunction     29  20     Venus 1.3°S of Saturn    30  17:53  Mars 0.4°S of BeehiveOct 01  13:04  Antares 3.9°S of Moon    02  02:09  Moon at Ascending Node     03  20:15  FIRST QUARTER MOON     11  19:06  FULL MOON     12  04:43  Moon at Apogee: 406435 km    13  12:28  Jupiter 4.8°S of Moon    13  14     Saturn in Conjunction with Sun     15  05:49  Pleiades 2.7°N of Moon    16  14:01  Moon at Descending Node     19  20:30  LAST QUARTER MOON     21  15     Orionid Meteor Shower    22  10:52  Regulus 5.8°N of Moon    26  05:26  Moon at Perigee: 357051 km    26  12:56  NEW MOON     27  19:14  Mercury 0.2°N of Moon: Occn.    27  22:11  Venus 1.8°N of Moon    28  18     Jupiter at Opposition     28  22:37  Antares 4.1°S of Moon    29  07:59  Moon at Ascending Node Nov 01  13     Mercury 2.0°S of Venus    02  09:38  FIRST QUARTER MOON     05  15     S Taurid Meteor Shower    08  06:20  Moon at Apogee: 406177 km    09  11:40  Jupiter 5.0°S of Moon    10  00:51  Venus 3.8°N of Antares    10  01:27  Mercury 1.9°N of Antares    10  11:21  Mars 1.3°N of Regulus    10  13:16  FULL MOON     11  04:32  Saturn 4.0°N of Spica    11  11:43  Pleiades 2.8°N of Moon    12  10:18  Aldebaran 5.9°S of Moon    12  15     N Taurid Meteor Shower    12  17:35  Moon at Descending Node     13  01     Mercury 2.0°S of Venus    14  02     Mercury at Greatest Elong: 22.7°E    17  21     Leonid Meteor Shower    18  08:09  LAST QUARTER MOON     18  18:42  Regulus 6.0°N of Moon    22  10:21  Spica 2.1°N of Moon    23  16:24  Moon at Perigee: 359692 km    24  23:10  NEW MOON     24  23:20  Partial Solar Eclipse; mag=0.905    25  18:02  Moon at Ascending Node     26  02:48  Mercury 1.7°S of Moon    26  21:29  Venus 2.8°S of MoonDec 02  02:52  FIRST QUARTER MOON     04  02     Mercury at Inferior Conjunction     04  23     Mercury at Perihelion     05  18:13  Moon at Apogee: 405414 km    06  13:10  Jupiter 5.2°S of Moon    08  18:26  Pleiades 2.8°N of Moon    09  16:51  Aldebaran 5.9°S of Moon    10  00:04  Moon at Descending Node     10  07:32  Total Lunar Eclipse; mag=1.106    10  07:36  FULL MOON     14  10     Geminid Meteor Shower    16  00:26  Regulus 6.0°N of Moon    17  17:48  LAST QUARTER MOON     19  18:37  Spica 2.1°N of Moon    21  19:56  Moon at Perigee: 364801 km    21  22:30  Winter Solstice     22  19     Ursid Meteor Shower    22  20     Mercury at Greatest Elong: 21.8°W    22  20:05  Antares 4.1°S of Moon    22  20:50  Mercury 2.6°N of Moon    23  04:36  Moon at Ascending Node     24  03:36  Mercury 6.3°N of Antares    24  11:06  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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