Moon Phases and Eclipses in 2014

moon phases

 Year      New Moon       First Quarter       Full Moon       Last Quarter

 2014   Jan  1  11:14     Jan  8  03:39     Jan 16  04:52     Jan 24  05:19    
        Jan 30  21:39     Feb  6  19:22     Feb 14  23:53     Feb 22  17:15    
        Mar  1  08:00     Mar  8  13:27     Mar 16  17:09     Mar 24  01:46    
        Mar 30  18:45     Apr  7  08:31     Apr 15  07:42 t   Apr 22  07:52    
        Apr 29  06:14 A   May  7  03:15     May 14  19:16     May 21  12:59    
        May 28  18:40     Jun  5  20:39     Jun 13  04:11     Jun 19  18:39    
        Jun 27  08:09     Jul  5  11:59     Jul 12  11:25     Jul 19  02:08    
        Jul 26  22:42     Aug  4  00:50     Aug 10  18:09     Aug 17  12:26    
        Aug 25  14:13     Sep  2  11:11     Sep  9  01:38     Sep 16  02:05    
        Sep 24  06:14     Oct  1  19:33     Oct  8  10:51 t   Oct 15  19:12    
        Oct 23  21:57 P   Oct 31  02:48     Nov  6  22:23     Nov 14  15:16    
        Nov 22  12:32     Nov 29  10:06     Dec  6  12:27     Dec 14  12:51    
        Dec 22  01:36     Dec 28  18:31     
 

 

In 2014, there are two solar eclipses and two total lunar eclipses as follows.

Partial solar eclipse

Partial solar eclipse (Photo credit: Wikipedia)

2014 Apr 15: Total Lunar Eclipse
2014 Apr 29: Annular Solar Eclipse
2014 Oct 08: Total Lunar Eclipse
2014 Oct 23: Partial Solar Eclipse

Predictions for the eclipses are summarized in Figures 123, and 4. World maps show the regions of visibility for each eclipse. The lunar eclipse diagrams also include the path of the Moon through Earth’s shadows. Contact times for each principal phase are tabulated along with the magnitudes and geocentric coordinates of the Sun and Moon at greatest eclipse.

All times and dates used in this publication are in Universal Time or UT. This astronomically derived time system is colloquially referred to as Greenwich Mean Time or GMT. To learn more about UT and how to convert UT to your own local time, see Time Zones and Universal Time.



Total Lunar Eclipse of April 15

The first eclipse of the year is well placed for observers throughout the Western Hemisphere. The eclipse occurs at the lunar orbit’s ascending node in Virgo. The apparent diameter of the Moon is close to its average since the eclipse occurs nearly midway between apogee (April 08 at 14:53 UT) and perigee (April 23 at 00:28 UT). This is the first of four consecutive total lunar eclipses in 2014 and 2015 (see Lunar Eclipse Tetrads).

The Moon’s orbital trajectory takes it through the southern half of Earth’s umbral shadow. Although the eclipse is not central, the total phase still lasts 78 minutes. The Moon’s path through Earth’s shadows as well as a map illustrating worldwide visibility of the event are shown in Figure 1. The times of the major eclipse phases are listed below.

Penumbral Eclipse Begins:  04:53:37 UT
          Partial Eclipse Begins:    05:58:19 UT
          Total Eclipse Begins:      07:06:47 UT
          Greatest Eclipse:          07:45:40 UT
          Total Eclipse Ends:        08:24:35 UT
          Partial Eclipse Ends:      09:33:04 UT
          Penumbral Eclipse Ends:    10:37:37 UT

At the instant of greatest eclipse[1] (07:45:40 UT) the Moon lies at the zenith for a point in the South Pacific about 3000 km southwest of the Galapagos Islands. The umbral eclipse magnitude[2] peaks at 1.2907 as the Moon’s northern limb passes 1.7 arc-minutes south of the shadow’s central axis. In contrast, the Moon’s southern limb lies 9.0 arc-minutes from the southern edge of the umbra and 40.0 arc-minutes from the shadow centre. Thus, the northern half of the Moon will appear much darker than the southern half because it lies deeper in the umbra. Since the Moon samples a large range of umbral depths during totality, its appearance will change significantly with time. It is not possible to predict the exact brightness distribution in the umbra, so observers are encouraged to estimate the Danjon value at different times during totality (see Danjon Scale of Lunar Eclipse Brightness). Note that it may also be necessary to assign different Danjon values to different portions of the Moon (i.e., north verses south).

During totality, the spring constellations are well placed for viewing so a number of bright stars can be used for magnitude comparisons. Spica (m = +1.05) is the most conspicuous star lying just 2° west of the eclipsed Moon. This juxtaposition reminds the author of the total lunar eclipse of 1968 Apr 13 when Spica appeared only 1.3° southwest of the Moon at mid-totality. The brilliant blue color of Spica made for a striking contrast with the crimson Moon. Just a week past opposition, Mars (m = -1.4) appears two magnitudes brighter than Spica and lies 9.5° northwest of the Moon. Arcturus (m = +0.15) is 32° to the north, Saturn (m = +0.2) is 26° to the east, and Antares (m = +1.07) is 44° to the southeast.

The entire event is visible from both North and South America. Observers in the western Pacific miss the first half of the eclipse because it occurs before moonrise. Likewise most of Europe and Africa experience moonset just as the eclipse begins. None of the eclipse is visible from north/east Europe, eastern Africa, the Middle East or Central Asia.

Table 1 lists predicted umbral immersion and emersion times for 25 well-defined lunar craters. The timing of craters is useful in determining the atmospheric enlargement of Earth’s shadow (see Crater Timings During Lunar Eclipses).

The April 15 eclipse is the 56th eclipse of Saros[3] 122. This series began on 1022 August 14 and is composed of 74 lunar eclipses in the following sequence: 22 penumbral, 8 partial, 28 total, 7 partial, and 9 penumbral eclipses (Espenak and Meeus, 2009). The last eclipse of the series is on 2338 October 29. Complete details for Saros 122 can be found at:

eclipse.gsfc.nasa.gov/LEsaros/LEsaros122.html



Annular Solar Eclipse of April 29

The first solar eclipse of 2014 occurs at the Moon’s descending node in southern Aries. This particular eclipse is rather unusual because the central axis of the Moon’s antumbral shadow misses Earth entirely while the shadow edge grazes the planet. Classified as a non-central annular eclipse, such events are rare. Out of the 3,956 annular eclipses occurring during the 5,000-year period -2000 to +3000, only 68 of them or 1.7% are non-central (Espenak and Meeus, 2006).

The northern edge of the antumbral shadow first touches down in Antarctica at 05:57:35 UT. The instant of greatest eclipse[4] occurs just six minutes later at 06:03:25 UT. For an observer at the geographic coordinates nearest the shadow axis (131° 15.6′ E, 79° 38.7′ S), the Sun would appear on the horizon during the 49-second annular phase. Six minutes later (06:09:36 UT), the antumbral shadow lifts off the surface of Earth as the annular eclipse ends. The entire zone of annularity appears as a small D-shaped region in eastern Antarctica (Figure 2).

A partial eclipse is seen within the much broader path of the Moon’s penumbral shadow, that includes the southern Indian Ocean, the southern edge of Indonesia and all of Australia (Figure 2). Local circumstances for a number of cities in Australia are found inTable 2. All times are given in Universal Time. The Sun’s altitude and azimuth, the eclipse magnitude[5] and obscuration[6] are all given at the instant of maximum eclipse.

This is the 21st eclipse of Saros 148 (Espenak and Meeus, 2006). The family began with a series of 20 partial eclipses starting on 1653 Sep 21. The 2014 Apr 29 eclipse is actually the first annular eclipse of the series. It will be followed by another annular on 2032 May 09. The series switches to hybrid on 2050 May 20 followed by the first 40 total eclipses on 2068 May 31. After a final 12 partial eclipses, Saros 148 terminates on 2987 Dec 12. Complete details for the 75 eclipses in the series (in the sequence of 20 partial, 2 annular, 1 hybrid, 40 total, and 12 partial) may be found at:

eclipse.gsfc.nasa.gov/SEsaros/SEsaros148.html



Total Lunar Eclipse of October 08

The second lunar eclipse of 2014 is also total and is best seen from the Pacific Ocean and bordering regions. The eclipse occurs at the Moon’s descending node in southern Pisces, two days after perigee (October 06 at 09:41 UT). This means that the Moon will appear 5.3% larger than it did during the April 15 eclipse (32.7 vs. 31.3 arc-minutes).

This time the orbital path of the Moon takes it through the northern half of Earth’s umbral shadow. The total phase lasts 59 minutes primarily because the diameter of the umbral shadow is larger (1.49° verses 1.39°). The lunar path through Earth’s shadows as well as a map illustrating worldwide visibility of the event are shown in Figure 3. The times of the major eclipse phases are listed below.

               Penumbral Eclipse Begins:   08:15:33 UT
               Partial Eclipse Begins:     09:14:48 UT
               Total Eclipse Begins:       10:25:10 UT
               Greatest Eclipse:           10:54:36 UT
               Total Eclipse Ends:         11:24:00 UT
               Partial Eclipse Ends:       12:34:21 UT
               Penumbral Eclipse Ends:     13:33:43 UT

At the instant of greatest eclipse (10:54:36 UT) the Moon lies near the zenith from a location in the Pacific Ocean about 2000 km southwest of Hawaii. At this time, the umbral magnitude peaks at 1.1659 as the Moon’s southern limb passes 6.6 arc-minutes north of the shadow’s central axis. In contrast, the Moon’s northern limb lies 5.4 arc-minutes from the northern edge of the umbra and 39.3 arc-minutes from the shadow centre. As a result, the southern half of the Moon will appear much darker than the northern half because it lies deeper in the umbra. The Moon samples a large range of umbral depths during totality so its appearance will change considerably with time. The exact brightness distribution in the umbra is difficult to predict, so observers are encouraged to estimate the Danjon value at different times during totality (see Danjon Scale of Lunar Eclipse Brightness). It may also be necessary to assign different Danjon values to different portions of the Moon (e.g., north vs. south).

During totality, the autumn constellations are well placed for viewing and the brighter stars can be used for magnitude comparisons. The center of the Great Square of Pegasus lies 15° to the northwest, its brightest star being Alpheratz (m = +2.02). Deneb Kaitos (m = +2.04) in Cetus is 30° south of the eclipsed Moon, while Hamal (m = +2.01) is 25° to the northeast, Aldebaran (m = +0.87) is 56° to the east, and Almach (m = +2.17) is 40° to the north.

Although relatively faint, the planet Uranus (m = +5.7) lies just 2/3° southeast of the Moon during totality. Is a transit of the Earth and Moon across the Sun’s disk visible from Uranus during the eclipse? An interesting idea but calculations show a miss. From Uranus, the Sun’s disk is only 1.7 arc-minutes in diameter and this is a very small target to hit. Nevertheless, transits of Earth from Uranus are possible – the next one takes place on 2024 November 17 (Meeus, 1989).

The entire October 08 eclipse is visible from the Pacific Ocean and regions immediately bordering it. The northwestern 1/3 of North America also witnesses all stages. Farther east, various phases occur after moonset. For instance, the Moon sets during totality from eastern Canada and the USA. Observers in South America also experience moonset during the early stages of the eclipse. All phases are visible from New Zealand and eastern 1/4 of Australia – the Moon rises during the early partial phases from Australia’s west coast. Most of Japan and easternmost Asia catch the entire eclipse as well. Farther west in Asia, various stages of the eclipse occur before moonrise. None of the eclipse is visible from Europe, Africa, and the Middle East.

Table 3 lists predicted umbral immersion and emersion times for 25 well-defined lunar craters. The timing of craters is useful in determining the atmospheric enlargement of Earth’s shadow (see Crater Timings During Lunar Eclipses).

The October 08 eclipse is the 42nd eclipse of Saros 127. This series is composed of 72 lunar eclipses in the following sequence: 11 penumbral, 18 partial, 16 total, 20 partial, and 7 penumbral eclipses (Espenak and Meeus, 2009). The family began with the penumbral eclipse of 1275 July 09, and ends with another penumbral eclipse on 2555 September 02. Complete details for Saros 127 can be found at:

eclipse.gsfc.nasa.gov/LEsaros/LEsaros127.html



Partial Solar Eclipse of October 23

The final event of 2014 occurs at the Moon’s ascending node in southern Virgo. Although it is only a partial solar eclipse, it is of particular interest because the event is widely visible from Canada and the USA (Figure 4).

The penumbral shadow first touches Earth’s surface near the Kamchatka Peninsula in eastern Siberia at 19:37:33 UT. As the shadow travels east, much of North America will be treated to a partial eclipse. The eclipse magnitude from cities like Vancouver (0.658), San Francisco (0.504), Denver (0.556), and Toronto (0.443) will surely attract the media’s attention.

Greatest eclipse occurs at 21:44:31 UT in Canada’s Nunavut Territory near Prince of Wales Island where the eclipse in the horizon will have a magnitude of 0.811. At that time, the axis of the Moon’s shadow will pass about 675 km above Earth’s surface. A sunset eclipse will be visible from the eastern half of the USA and Canada (except for the far northeast). The partial eclipse ends when the penumbra leaves Earth at 23:51:40 UT.

Local circumstances and eclipse times for a number of cities in Canada and Mexico are listed in Table 4, and for the USA in Table 5. All times are in Local Daylight Time. The Sun’s altitude and azimuth, the eclipse magnitude and eclipse obscuration are all given at the instant of maximum eclipse. When the eclipse is in progress at sunset, this information is indicated by ‘- s’.

The NASA JavaScript Solar Eclipse Explorer is an interactive web page that can quickly calculate the local circumstances of the eclipse from any geographic location not included in Tables 4 and 5:

Javascript Solar Eclipse Explorer: eclipse.gsfc.nasa.gov/JSEX/JSEX-index.html

This is the 9th eclipse of Saros 153 (Espenak and Meeus, 2006). The series began on 1870 Jul 28 with a string of 13 partial eclipses. The first of 49 annular eclipses begins on 2104 Dec 17. The series ends with a set of 8 partial eclipses the last of which occurs on 3114 Aug 22. In all, Saros 153 produces 70 solar eclipses in the sequence of 13 partial, 49 annular, and 8 partial eclipses. Complete details for the series can be found at:

eclipse.gsfc.nasa.gov/SEsaros/SEsaros153.html


Lunar Eclipse Tetrads

The lunar eclipses of 2014 are the first of four consecutive total lunar eclipses – a series known as a tetrad. During the 5000-year period from -1999 to +3000, there are 4378 penumbral eclipses (36.3%), 4207 partial lunar eclipses (34.9%) and 3479 total lunar eclipses (28.8%). Approximately 16.3% (568) of all total eclipses belong to one of the 142 tetrads occurring over this period (Espenak and Meeus, 2009). The mechanism causing tetrads involves the eccentricity of Earth’s orbit in conjunction with the timing of eclipse seasons (Meeus, 2004). During the present millennium, the first eclipse of every tetrad occurs sometime from February to July. In later millennia, the first eclipse date gradually falls later in the year because of precession.

Italian astronomer Giovanni Schiaparelli first pointed out that the frequency of tetrads is variable over time. He noticed that tetrads were relatively plentiful during one 300-year interval, while none occurred during the next 300 years. For example, there are no tetrads from 1582 to 1908, but 17 tetrads occur during the following 2 and 1/2 centuries from 1909 to 2156. The ~565-year period of the tetrad “seasons” is tied to the slowly decreasing eccentricity of Earth’s orbit. Consequently, the tetrad period is gradually decreasing (Meeus, 2004). In the distant future when Earth’s eccentricity is 0, tetrads will no longer be possible.

The umbral magnitudes of the total eclipses making up a tetrad are all relatively small. For the 300-year period 1901 to 2200, the largest umbral magnitude of a tetrad eclipse is 1.4251 on 1949 Apr 13. For comparison, some other total eclipses during this period are much deeper. Two examples are the total eclipses of 2000 Jul 16 and 2029 Jun 26 with umbral magnitudes of 1.7684 and 1.8436, respectively.

Table 6 gives the dates of each eclipse in the 8 tetrads occurring during the 21st century. The tetrad prior to 2014-15 was in 2003-04 while the next group is nearly 20 years later in 2032-33.


Explanatory Information

Solar Eclipse Figures

Lunar Eclipse Figures

Shadow Diameters and Lunar Eclipses

Danjon Scale of Lunar Eclipse Brightness

Crater Timings During Lunar Eclipses


Eclipse Altitudes and Azimuths

The altitude a and azimuth A of the Sun or Moon during an eclipse depend on the time and the observer’s geographic coordinates. They are calculated as follows:

h = 15 (GST + UT - α ) + λ
a = arcsin [sin δ sin φ + cos δ cos h cos φ]
A = arctan [-(cos δ sin h)/(sin δ cos φ - cos δ cos h sin φ)]

where

h = hour angle of Sun or Moon
a = altitude
A = azimuth
GST = Greenwich Sidereal Time at 0:00 UT
UT = Universal Time
α = right ascension of Sun or Moon
δ = declination of Sun or Moon
λ = observer's longitude (east +, west -)
φ = observer's latitude (north +, south -)

During the eclipses of 2014, the values for GST and the geocentric Right Ascension and Declination of the Sun or the Moon (at greatest eclipse) are as follows:

Eclipse              Date           GST         α          δ
Total Lunar       2014 Apr 15     13.560     13.556     -10.050
Annular Solar     2014 Apr 29     14.475      2.431      14.448
Total Lunar       2014 Oct 08      1.133      0.919       6.307
Partial Solar     2014 Oct 23      2.148     13.887     -11.613

moon

Two web based tools that can also be used to calculate the local circumstances for all solar and lunar eclipses visible from any location. They are the Javascript Solar Eclipse Explorer and the Javascript Lunar Eclipse Explorer. The URLs for these tools are:

Javascript Solar Eclipse Explorer: eclipse.gsfc.nasa.gov/JSEX/JSEX-index.html

Javascript Lunar Eclipse Explorer: eclipse.gsfc.nasa.gov/JLEX/JLEX-index.html

 NASA’s Six Millennium Catalog of Phases of the Moon.

All above information via NASA.

The Moon and Phases for 2013

The presence of the Moon moderates Earth’s wobble on its axis, leading to a relatively stable climate over billions of years. From Earth, we always see the same face of the Moon because the Moon rotates once on its own axis in the same time that it travels once around Earth (called synchronous rotation).

The light areas of the Moon are known as the highlands. The dark features, called maria (Latin for seas), are impact basins that were filled with lava between 4 and 2.5 billion years ago.

moon 1

Though the Moon has no internally generated magnetic field, areas of magnetism are preserved in the lunar crust, but how this occurred is a mystery. The early Moon appears not to have had the right conditions to develop an internal dynamo, the mechanism for global magnetic fields for the terrestrial planets.

How did the Moon come to be? The leading theory is that a Mars-sized body collided with Earth approximately 4.5 billion years ago, and the resulting debris from both Earth and the impactor accumulated to form our natural satellite. The newly formed Moon was in a molten state. Within about 100 million years, most of the global “magma ocean” had crystallized, with less dense rocks floating upward and eventually forming the lunar crust.

2013 Phases of the Moon

NOTE: All times are Universal time (UTC); to convert to local time add or subtract the difference between your time zone and UTC, remembering to include any additional offset due to summer time for dates when it is in effect.

New Moon First Quarter
Day Time Solar
Eclipse
Day Time
         
11/01/13 19:44:00   18/01/13 23:45:00
10/02/13 07:20:00   17/02/13 20:31:00
11/03/13 19:51:00   19/03/13 17:27:00
10/04/13 09:35:00   18/04/13 12:31:00
10/05/13 00:28:00 Annular 18/05/13 04:34:00
08/06/13 15:56:00   16/06/13 17:24:00
08/07/13 07:14:00   16/07/13 17:24:00
06/08/13 21:51:00   14/08/13 10:56:00
05/09/13 11:36:00   12/09/13 17:08:00
05/10/13 00:34:00   11/10/13 23:02:00
03/11/13 12:50:00 Hybrid
Solar
10/11/13 05:57:00
03/12/13 00:22:00   09/12/13 15:12:00
Full Moon Last Quarter
Day Time Lunar
Eclipse
Day Time
      05/01/13 03:58:00
27/01/13 04:38:00   03/02/13 13:56:00
25/02/13 20:26:00   04/03/13 21:53:00
27/03/13 09:27:00   03/04/13 04:37:00
25/04/13 19:57:00 Partial
(Umbral)
02/05/13 11:14:00
25/05/13 04:25:00 Penumbral 31/05/13 18:58:00
23/06/13 11:32:00   30/06/13 04:53:00
22/07/13 18:15:00   29/07/13 17:43:00
21/08/13 01:45:00   28/08/13 09:35:00
19/09/13 11:13:00   27/09/13 03:55:00
18/10/13 23:38:00 Penumbral 26/10/13 23:40:00
17/11/13 15:16:00   25/11/13 19:28:00
17/12/13 09:28:00   25/12/13 13:48:00
A waxing crescent moon 17 jan 2013

A waxing crescent moon 17 jan 2013

Perigee and Apogee Dates and Times

Perigee  
Day Time Distance in
kilometres a
Closest
or most
distant b
Interval c
   
   
10/01/13 10:27:00 360047   N-1d 9h
07/02/13 12:10:00 365313   N-2d19h
05/03/13 23:21:00 369953   N-5d20h
31/03/13 03:56:00 367493   F+3d18h
27/04/13 19:49:00 362267   F+1d23h
26/05/13 01:46:00 358374   F+ 21h
23/06/13 11:11:00 356989     ++ F- 0h
21/07/13 20:28:00 358401   F- 21h
19/08/13 01:27:00 362264   N-2d18h
15/09/13 16:35:00 367387   N-3d18h
10/10/13 23:07:00 369811   N+5d22h
06/11/13 09:29:00 365361   N+2d20h
04/12/13 10:16:00 360063   N+1d 9h
Apogee
Day Time Distance in
kilometres a
Closest
or most
distant b
Interval c
 
 
22/01/13 10:53:00 405311   F-1d17h
19/02/13 06:31:00 404473   F-6d13h
19/03/13 03:14:00 404261   N+7d 7h
15/04/13 22:23:00 404864   N+5d12h
13/05/13 13:32:00 405826   N+3d13h
09/06/13 21:41:00 406486     – N+1d 5h
07/07/13 00:37:00 406491     — N-1d 6h
03/08/13 08:54:00 405833   N-3d12h
30/08/13 23:47:00 404882   F-5d11h
27/09/13 18:18:00 404308   F-7d 6h
25/10/13 14:26:00 404560   F+6d18h
22/11/13 09:51:00 405445   F+4d18h
19/12/13 23:50:00 406267     + F+2d14h

a:  For each perigee and apogee the distance in kilometres between the centres of the Earth and Moon is given. Perigee and apogee distances are usually accurate to within a few kilometres compared to values calculated with the definitive ELP 2000-82 theory of the lunar orbit; the maximum error over the years 1977 through 2022 is 12km in perigee distance and 6km at apogee.

b:  The closest perigee and most distant apogee of the year are marked with “++” if closer in time to full Moon or “–” if closer to new Moon. Other close-to-maximum apogees and perigees are flagged with a single character, again indicating the nearer phase. Following the flags is the interval between the moment of perigee or apogee and the closest new or full phase; extrema cluster on the shorter intervals, with a smaller bias toward months surrounding the Earth’s perihelion in early January.

c:  “F” indicates the perigee or apogee is closer to full Moon, and “N” that new Moon is closer. The sign indicates whether the perigee or apogee is before (“-“) or after (“+”) the indicated phase, followed by the interval in days and hours. Scan for plus signs to find “photo opportunities” where the Moon is full close to apogee and perigee

moon

Moon phases

As the relative position of the Sun, Moon and Earth changes, differing proportions of the Moon’s visible surface are illuminated by the Sun. The phases of the Moon are specific instances in this process.

New moon

A new Moon occurs when the apparent longitudes of the Moon and Sun differ by 0°. At this time, the Moon does not appear to be illuminated.

First quarter

Occurs when the apparent longitudes of the Moon and Sun differ by 90°. At this time 50 per cent of the Moon’s visible surface is illuminated.

Full moon

Occurs when the apparent longitudes of the Moon and Sun differ by 180°. At this time 100 per cent of the Moon’s visible surface is illuminated.

Last quarter

Occurs when the apparent longitudes of the Moon and Sun differ by 270°. At this time 50 per cent of the Moon’s visible surface is illuminated.

Moonrise and moonset

Moonrise

Moonrise is defined as the instant when, in the eastern sky, under ideal meteorological conditions, with standard refraction of the Moon’s rays, the upper edge of the Moon’s disk is coincident with an ideal horizon.

Moonset

Moonset is defined as the instant when, in the western sky, under ideal meteorological conditions, with standard refraction of the Moon’s rays, the upper edge of the Moon’s disk is coincident with an ideal horizon.

Equinoxes and Solstices

The equinoxes represents either of two times of the year when the Sun crosses the plane of the Earth’s equator and day and night are of equal length, while the solstices is either of the two times of the year when the Sun is at its greatest distance from the celestial equator.

Uploaded on 20 Feb 2012

New images acquired by NASA’s Lunar Reconnaissance Orbiter (LRO) spacecraft show that the moon’s crust is being slightly stretched, forming small valleys – at least in some small areas. High-resolution images obtained by the Lunar Reconnaissance Orbiter Camera (LROC) provide evidence that these valleys are very young, suggesting the moon has experienced relatively recent geologic activity.

Smithsonian Institution Senior Scientist Tom Watters explains more about the moon’s recent geological activity in this short video.

Night Sky: Visible Planets, Moon Phases & Events, January 2013

How Moon Phases Work

via Space Dot Com

by Geoff Gaherty , (Space.Com) Starry Night Education
Date: 13 August 2012

Fact or fiction?

The phases of the moon are caused by the shadow of the Earth falling on the moon.

Fiction!

This is probably the most commonly held misconception in all astronomy. Here’s how the moon’s phases really come about:

The moon is a sphere that travels once around the Earth every 29.5 days. As it does so, it is illuminated from varying angles by the sun. At “new moon,” the moon is between the Earth and sun, so that the side of the moon facing towards us receives no direct sunlight, and is lit only by dim sunlight reflected from the Earth. As it moves around the Earth, the side we can see gradually becomes more illuminated by direct sunlight.

How Moon Phases Work

Here’s how the moon changes phases as it orbits the Earth, constantly changing the angle that sunlight hits the moon and is reflected, or not, to our eyes.
CREDIT: Starry Night Software

After a week, the moon is 90 degrees away from the sun in the sky and is half illuminated, what we call “first quarter” because it is about a quarter of the way around the Earth.

A week after this, the moon is 180 degrees away from the sun, so that sun, Earth and moon form a line. The moon is fully illuminated by the sun, so this is called “full moon.” This is the only time in the whole month when the Earth’s shadow is anywhere close to the moon. The Earth’s shadow points towards the moon at this time, but usually the moon passes above or below the shadow and no eclipse occurs.

A week later the moon has moved another quarter of the way around the Earth, to the third quarter position. The sun’s light is now shining on the other half of the visible face of the moon.

Finally, a week later, the moon is back to its new moon starting position. Usually it passes above or below the sun, but occasionally it passes right in front of the sun, and we get an eclipse of the sun.

So, the moon’s phases are not caused by the shadow of the Earth falling on the moon. In fact the shadow of the Earth falls on the moon only twice a year, when there are lunar eclipses.

This article was provided to SPACE.com by Starry Night Education, the leader in space science curriculum solutions. Amateur astronomer Geoff Gaherty operates his own Foxmead Observatory in Coldwater, Ontario, Canada.

A SEN Image
Links to story at SEN: Our Solar System
Moon Phase and Liberation, 2013

Dial-A-Moon At NASA, new interactive tool.

Frame 0081
Example only; the following Information when Astro’s article was Published

Time Friday, January 04, 2013, 08:00 UT
Phase 59.1%
Diameter 1880.3 arcseconds
Distance 381174 km (29.91 Earth diameters)
J2000 Right Ascension, Declination 12h 6m 49s, -5° 5′ 45″
Subsolar Longitude, Latitude -86.114°, 1.181°
Sub-Earth Longitude, Latitude -6.519°, 5.181°
Position Angle 24.462°

A pretty Moon

The animation archived on this page shows the geocentric phase, libration, position angle of the axis, and apparent diameter of the Moon throughout the year 2013, at hourly intervals. Until the end of 2013, the initial Dial-A-Moon image will be the frame from this animation for the current hour.

Published on 20 Nov 2012

This visualization shows the moon’s phase and liberation throughout the year 2013, at hourly intervals. Each frame represents one hour. In addition, this visualization also shows other relevant information, including moon orbit position, sub earth and sub solar points, distance from the Earth. Click each graphic to learn more about what it means! Finally, to learn more about this visualization, or to see what the moon will look like at any hour in 2013, visit http://svs.gsfc.nasa.gov/goto?4000!

This video is public domain and can be downloaded at:http://svs.gsfc.nasa.gov/goto?4000

The jagged, cratered, airless lunar terrain casts sharp shadows that clearly outline the Moon’s surface features for observers on Earth. This is especially true near the terminator, the line between day and night, where surface features appear in high relief. Elevation measurements by the Lunar Orbiter Laser Altimeter (LOLA) aboard the Lunar Reconnaissance Orbiter (LRO) make it possible to simulate shadows on the Moon’s surface with unprecedented accuracy and detail.

The Moon always keeps the same face to us, but not exactly the same face. Because of the tilt and shape of its orbit, we see the Moon from slightly different angles over the course of a month. When a month is compressed into 24 seconds, as it is in this animation, our changing view of the Moon makes it look like it’s wobbling. This wobble is calledlibration.

The word comes from the Latin for “balance scale” (as does the name of the zodiac constellation Libra) and refers to the way such a scale tips up and down on alternating sides. The sub-Earth point gives the amount of libration in longitude and latitude. The sub-Earth point is also the apparent center of the Moon’s disk and the location on the Moon where the Earth is directly overhead.

The Moon is subject to other motions as well. It appears to roll back and forth around the sub-Earth point. The roll angle is given by the position angle of the axis, which is the angle of the Moon’s north pole relative to celestial north. The Moon also approaches and recedes from us, appearing to grow and shrink. The two extremes, called perigee (near) and apogee (far), differ by more than 10%.

The most noticed monthly variation in the Moon’s appearance is the cycle of phases, caused by the changing angle of the Sun as the Moon orbits the Earth. The cycle begins with the waxing (growing) crescent Moon visible in the west just after sunset. By first quarter, the Moon is high in the sky at sunset and sets around midnight. The full Moon rises at sunset and is high in the sky at midnight. The third quarter Moon is often surprisingly conspicuous in the daylit western sky long after sunrise.

Celestial north is up in these images, corresponding to the view from the northern hemisphere. The descriptions of the print resolution stills also assume a northern hemisphere orientation. To adjust for southern hemisphere views, rotate the images 180 degrees, and substitute “north” for “south” in the descriptions.

The phase and libration of the Moon for 2013, at hourly intervals. Includes supplemental graphics that display the Moon's orbit, subsolar and sub-Earth points, and the Moon's distance from Earth at true scale. The phase and libration of the Moon for 2013, at hourly intervals. Includes supplemental graphics that display the Moon’s orbit, subsolar and sub-Earth points, and the Moon’s distance from Earth at true scale.
Duration: 4.9 minutes
Available formats:
1920×1080 MPEG-4   117 MB
1280×720   MPEG-4   57 MB
640×360     MPEG-4   20 MB
1920×1080 Frames (Fancy)
320×180     PNG           143 KB
160×80       PNG           40 KB
80×40         PNG           11 KB
How to play our movies
The phase and libration of the Moon for 2013 at hourly intervals, with music, titles, supplemental graphics, and transcript. The phase and libration of the Moon for 2013 at hourly intervals, with music, titles, supplemental graphics, and transcript.
Duration: 5.3 minutes
Available formats:
1920×1080 (29.97 fps) QT (YouTube) 285 MB
1280×720 (29.97 fps) QT (YouTube) 192 MB
1280×720 (29.97 fps) QT (ProRes) 2 GB
1280×720 (29.97 fps) WMV (Windows) 169 MB
960×540 (29.97 fps) MPEG-4 (AppleTV) 152 MB
640×360 (29.97 fps) QT         116 MB
640×360 (29.97 fps) MPEG-4 (iPod) 60 MB
320×240 (29.97 fps) MPEG-4 (iPod) 30 MB
320×180     PNG           143 KB
How to play our movies
The phase and libration of the Moon for 2013, at hourly intervals. The full-resolution frames include an alpha channel. The phase and libration of the Moon for 2013, at hourly intervals. The full-resolution frames include an alpha channel.
Duration: 4.9 minutes
Available formats:
1920×1080 MPEG-4   84 MB
1280×720   MPEG-4   38 MB
640×360     MPEG-4   11 MB
1920×1080 Frames (Plain)
560×560     Frames
216×216     Frames
320×180     PNG           105 KB
How to play our movies
The phase and libration of the Moon for 2013 at hourly intervals, with music, titles, and transcript. The phase and libration of the Moon for 2013 at hourly intervals, with music, titles, and transcript.
Duration: 5.3 minutes
Available formats:
1920×1080 (29.97 fps) QT (YouTube) 169 MB
1280×720 (29.97 fps) QT (YouTube) 171 MB
1280×720 (29.97 fps) QT (ProRes) 1 GB
1280×720 (29.97 fps) WMV (Windows) 146 MB
960×540 (29.97 fps) MPEG-4 (AppleTV) 134 MB
640×360 (29.97 fps) MPEG-4 (iPod) 60 MB
320×240 (29.97 fps) MPEG-4 (iPod) 24 MB
640×360 (29.97 fps) QT         90 MB
320×180     PNG           105 KB
How to play our movies
The orbit of the Moon in 2013, viewed from the north pole of the ecliptic, with the vernal equinox to the right. The sizes of the Earth and Moon are exaggerated by a factor of 30. The frames include an alpha channel. The orbit of the Moon in 2013, viewed from the north pole of the ecliptic, with the vernal equinox to the right. The sizes of the Earth and Moon are exaggerated by a factor of 30. The frames include an alpha channel.
Duration: 4.9 minutes
Available formats:
420×420     MPEG-4   10 MB
420×420     Frames
320×180     PNG           10 KB
How to play our movies
From this birdseye view, it’s somewhat easier to see that the phases of the Moon are an effect of the changing angles of the sun, Moon and Earth. The Moon is full when its orbit places it in the middle of the night side of the Earth. First and Third Quarter Moon occur when the Moon is along the day-night line on the Earth.The First Point of Aries is at the 3 o’clock position in the image. The sun is in this direction at the spring equinox. You can check this by freezing the animation at the 1:03 mark, or by freezing the full animation with the time stamp near March 20 at 11:00 UTC. This direction serves as the zero point for both ecliptic longitude and right ascension.The north pole of the Earth is tilted 23.5 degrees toward the 12 o’clock position at the top of the image. The tilt of the Earth is important for understanding why the north pole of the Moon seems to swing back and forth. In the full animation, watch both the orbit and the “gyroscope” Moon in the lower left. The widest swings happen when the Moon is at the 3 o’clock and 9 o’clock positions. When the Moon is at the 3 o’clock position, the ground we’re standing on is tilted to the left when we look at the Moon. At the 9 o’clock position, it’s tilted to the right. The tilt itself doesn’t change. We’re just turned around, looking in the opposite direction.
An animated diagram of the subsolar and sub-Earth points for 2013. The Moon's north pole, equator, and meridian are indicated. The frames include an alpha channel. An animated diagram of the subsolar and sub-Earth points for 2013. The Moon’s north pole, equator, and meridian are indicated. The frames include an alpha channel.
Duration: 4.9 minutes
Available formats:
320×320     MPEG-4   5 MB
320×320     Frames
320×180     PNG           21 KB
How to play our movies
The subsolar and sub-Earth points are the locations on the Moon’s surface where the sun or the Earth are directly overhead, at the zenith. A line pointing straight up at one of these points will be pointing toward the sun or the Earth. The sub-Earth point is also the apparent center of the Moon’s disk as observed from the Earth.In the animation, the blue dot is the sub-Earth point, and the yellow dot is the subsolar point. The lunar latitude and longitude of the sub-Earth point is a measure of the Moon’s libration. For example, when the blue dot moves to the left of the meridian (the line at 0 degrees longitude), an extra bit of the Moon’s western limb is rotating into view, and when it moves above the equator, a bit of the far side beyond the north pole becomes visible.At any given time, half of the Moon is in sunlight, and the subsolar point is in the center of the lit half. Full Moon occurs when the subsolar point is near the center of the Moon’s disk. When the subsolar point is somewhere on the far side of the Moon, observers on Earth see a crescent phase.
An animated diagram of the Moon's distance from the Earth for 2013. The sizes and distances are true to scale, and the lighting and Earth-tilt are correct. The frames include an alpha channel. An animated diagram of the Moon’s distance from the Earth for 2013. The sizes and distances are true to scale, and the lighting and Earth-tilt are correct. The frames include an alpha channel.
Duration: 4.9 minutes
Available formats:
1920×1080 MPEG-4   2 MB
1280×720   MPEG-4   1 MB
640×360     MPEG-4   656 KB
1920×1080 Frames (Distance)
320×180     PNG           1 KB
How to play our movies
The Moon’s orbit around the Earth isn’t a perfect circle. The orbit is slightly elliptical, and because of that, the Moon’s distance from the Earth varies between 28 and 32 Earth diameters, or about 356,400 and 406,700 kilometers. In each orbit, the smallest distance is called perigee, from Greek words meaning “near earth,” while the greatest distance is called apogee. The Moon looks largest at perigee because that’s when it’s closest to us.The animation follows the imaginary line connecting the Earth and the Moon as it sweeps around the Moon’s orbit. From this vantage point, it’s easy to see the variation in the Moon’s distance. Both the distance and the sizes of the Earth and Moon are to scale in this view. In the full-resolution frames, the Earth is 50 pixels wide, the Moon is 14 pixels wide, and the distance between them is about 1500 pixels, on average.Note too that the Earth appears to go through phases just like the Moon does. For someone standing on the surface of the Moon, the sun and the stars rise and set, but the Earth doesn’t move in the sky. It goes through a monthly sequence of phases as the sun angle changes. The phases are the opposite of the Moon’s. During New Moon here, the Earth is full as viewed from the Moon.
Waxing crescent. Visible toward the southwest in early evening. Waxing crescent. Visible toward the southwest in early evening.Available formats:
3600 x 3600     TIFF       8 MB
320 x 320         PNG     280 KB
First quarter. Visible high in the southern sky in early evening. First quarter. Visible high in the southern sky in early evening.Available formats:
3600 x 3600     TIFF       9 MB
320 x 320         PNG     293 KB
Waxing gibbous. Visible to the southeast in early evening, up for most of the night. Waxing gibbous. Visible to the southeast in early evening, up for most of the night.Available formats:
3600 x 3600     TIFF     12 MB
320 x 320         PNG     352 KB
Full Moon. Rises at sunset, high in the sky around midnight. Visible all night. Full Moon. Rises at sunset, high in the sky around midnight. Visible all night.Available formats:
3600 x 3600     TIFF     16 MB
320 x 320         PNG     398 KB
Waning gibbous. Rises after sunset, high in the sky after midnight, visible to the southwest after sunrise. Waning gibbous. Rises after sunset, high in the sky after midnight, visible to the southwest after sunrise.Available formats:
3600 x 3600     TIFF     12 MB
320 x 320         PNG     358 KB
Third quarter. Rises around midnight, visible to the south after sunrise. Third quarter. Rises around midnight, visible to the south after sunrise.Available formats:
3600 x 3600     TIFF     10 MB
320 x 320         PNG     317 KB
Waning crescent. Low to the east before sunrise. Waning crescent. Low to the east before sunrise.Available formats:
3600 x 3600     TIFF       7 MB
320 x 320         PNG     281 KB
New Moon. By the modern definition, New Moon occurs when the Moon and Sun are at the same geocentric ecliptic longitude. The part of the Moon facing us is completely in shadow then. Pictured here is the traditional New Moon, the earliest visible waxing crescent, which signals the start of a new month in many lunar and lunisolar calendars. New Moon. By the modern definition, New Moon occurs when the Moon and Sun are at the same geocentric ecliptic longitude. The part of the Moon facing us is completely in shadow then. Pictured here is the traditional New Moon, the earliest visible waxing crescent, which signals the start of a new month in many lunar and lunisolar calendars.Available formats:
3600 x 3600     TIFF       6 MB
320 x 320         PNG     261 KB

Published on 20 Nov 2012

This visualization shows the moon’s phase (Only no detail) and liberation throughout the year 2013, at hourly intervals. Each frame represents one hour

Another cool link to an Interactive MOON Guide 

Night Sky: Visible Planets, Moon Phases & Events, January 2013

Mark Thompson’s guide to the Moon 

Via SEN

Earth s only moon is 3,476 km in diameter & orbits at an average distance of 384,400km
Earth’s only moon is 3,476 km in diameter & orbits at an average distance of 384,400km

By Mark Thompson 24 August 2011

There can be few objects that have inspired both artists and scientists as much as the Moon. Perhaps surprisingly its appearance has barely changed in the thousands of years that mankind has walked the Earth and ancient civilisations enjoyed much the same view as the one we see today. During the Moon’s relentless orbit around the Earth it has witnessed civilisations come and go, entire species evolve and die out and even continents slowly shift. The one thing that has changed over all those years though is our understanding of it, and its still giving us plenty of surprises.

As natural planetary satellites go, the Moon is actually quite large with a diameter of 3,476km (2,155 miles) around the equator. It orbits the Earth at an average distance of 384,400km (238,000 miles) but this varies from its closest, or perigee at 362,570km (225,000 miles) to its most distant point, or apogee of 405,410km (251,000 miles). There are a couple of things people will always think of when you mention the Moon: craters and phases which can both be observed without a telescope.

The phases of the Moon are simple to understand and anyone who has looked at it over a series of nights will notice that it changes progressively night after night with a whole cycle taking about a month. In fact the word month has its origin in the word Moon relating to the approximate length of a full lunar phase cycle. To understand the phases its important to realise that we only see the Moon because it’s a sphere and reflects sunlight – turn the Sun off and the Moon would no longer be visible.

We see the phases change as the Moon orbits around the Earth and the angle between the Sun and Moon alters. During a full Moon, the Sun and Moon are opposite each other in the sky and we see the fully illuminated or daytime face, but at new Moon they are both in the same direction and we see the night time portion of the Moon. As it moves around the Earth, the angle between the Earth, Sun and Moon changes and we see varying amounts of the daytime/nighttime side.The line between the illuminated and un-illuminated faces is called the terminator and its down this line where the Sun is just rising or setting.

From an observational point of view, the surface features are much more prominent if observed when they are near the terminator. The low altitude of the Sun from that point means the shadows cast by the features are much longer making them stand out clearly against the lunar surface. The worst time to observe the Moon is when it’s full and the shadows are minimal.

The phases of the Moon are a little more complicated than I’ve just explained though because the orbit of the Moon around the Earth is very slightly tilted with respect to the Earth’s orbit around the Sun. If it wasn’t then every time we had a full Moon the Earth would block sunlight from reaching the Moon and we would see a lunar eclipse. Clearly we don’t have one every month and its because the Moon’s orbit is tilted that on most occasions the Moon is slightly above or below the Earth’s shadow.

Look at the Moon more closely and you will see dark grey patches, turn binoculars or even a telescope on it and some will turn into great plains while others turn into cavernous craters. The craters were created by meteoric impacts where pieces of space rock smashed into the lunar surface. We see evidence of this process throughout the Solar System even here on Earth. The larger plains, or mare as they are properly called, are the aftermath of much larger impacts that have cracked the lunar surface allowing molten lava to seep up through the mantle. The lava solidifies over time leaving the plains we see today. Before good quality telescopes it was thought these great plains were actually lunar seas.

Another effect of the Moon’s orbit around the Earth are the tides. Like the Earth, the Moon has a gravitational pull and as a result it pulls on the Earth producing a bulge. As the Earth spins once on its axis it ‘passes underneath’ the bulge which we then experience as a tide. There are actually two bulges, one pointing roughly toward the Moon, the other in the opposite direction. When a location passes under the bulge it’s seen as high tide, hence we see two every day.

This bulge is pretty crucial and is having a big impact on the Earth-Moon system. You would think that the bulge lies directly between the Earth and Moon, given that it’s the pull of the Moon’s gravity that causes it. It turns out that the rotation of the Earth drags the bulge a little ahead of the Moon in its orbit. As it lays ahead of the Moon, the extra ‘lump’ of material produces a little extra pull on the Moon causing it to accelerate in its orbit. If you accelerate an orbiting object, it moves into a higher orbit -in other words, it moves further away. Thanks to the Apollo astronauts who left a special mirror on the surface, we can now accurately measure its distance and have found that the Moon is moving away from the Earth at a rate of 3.8cm per year!

It’s not only the Earth that experiences the tides, the Moon too has tides, though to a much lesser degree. The gravitational pull from Earth acts to distort the Moon and produce a lunar tidal bulge toward the Earth. When the Moon first formed it was spinning much faster than it does today and its rotation displaced the tidal bulge from its alignment between the Earth and Moon. The Earth’s gravitational pull still acted upon this bulge causing a braking effect on the Moon’s rotation. Over many millions of years this tidal interaction caused the Moon to slow down so much that it now rotates once on its axis for every orbit around the Earth, every 29.5 days. It’s an effect called captured or synchronous rotation and its result is that we now only ever see one half of the Moon from Earth. In reality we see can see a little more than 50% but this is due to the Moon’s orbital properties allowing us to glance a little further around.

With the Moon moving away from Earth it would be reasonable to assume that at some point they were in the same place. It is believed that the Moon was in fact once part of the Earth. At the time the Earth formed, the Solar System was a war zone with large chunks of rock and proto-planets flying around at ballistic speed. One piece about the size of Mars is thought to have smashed into the Earth throwing vast amounts of material into orbit. It’s believed that most of the heavy elements settled back on Earth while the lighter material stayed in orbit. Recent studies suggest that two moons could have formed, sharing the same orbit, which ultimately collided forming the Moon we see today. This new theory nicely accounts for the observation that one side of the Moon seems to have a much thicker crust which is now thought to be the remains of the Moon’s ancient companion.

Perhaps one of the most incredible discoveries in recent years was the discovery of water ice in some of the deep lunar craters. In these deep craters, that remain almost permanently in shadow, temperatures remain sub zero all year round allowing the ice crystals to form. This discovery opens up tantalising possibilities for future space exploration. The water molecules on the Moon could be harnessed for and purified for future explorers to drink. Taking this a step further, separate the water molecules into their hydrogen and oxygen components and they could be used to create rocket fuel for further onward exploration. No longer can we consider the Moon as a lifeless and hostile place, instead its becoming more likely that mankind’s next step out into the Solar System will involve using the Moon as an outpost for future giant leaps!

Tools from Moon Connection
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Moon Phases Calendar
Current Moon Phase
Moon Phase Module
iGoogle Moon Gadget
Gravity On The Moon
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Moon Phases Explained
Moon Trading
Fishing By Moon Phase
Night Photography
Moon Phase Lesson Plan
Moon Glossary
Topics
Tides Explained
One Side of Moon
Moon Facts
Apollo Missions
Apollo 13
Apollo 11
School Moon Activity
Astrological Moon Sign
The Moon Cycle
Lunar Eclipse
Solar Eclipse
Lunar vs Solar Eclipse
Apogee and Perigee
Earthshine
Full Moon Names
Harvest Moon
Blue Moon

RELATED LINKS AT SEN and NASA