Eclipse season
Encyclopedia
Eclipse seasons are the only times during a year eclipse
s can occur, due to the 5° inclination of the moon's orbit. Each season lasts for approximately 33 days and repeats just short of six months, thus there are always two full eclipse seasons each year. 2 to 3 eclipses always occur each eclipse season. During the season the inclination of the moon is low, hence the Sun, Moon and Earth become close enough in alignment (syzygy
) for an eclipse to occur.
to allow for an eclipse
to occur. During the season, whenever there is a full moon a lunar
eclipse will occur and whenever there is a new moon a solar eclipse
will occur. If the sun is close enough to a node, then a total eclipse
will occur. Each season lasts from 31 to 37 days, recurring about every 6 months. At least two (one solar and one lunar, in any order), and at most three eclipses (solar, lunar, then solar again, or vice versa), will occur during every eclipse season. This is because it is about 15 days (a fortnight) between full moon and new moon and vice versa. If there is an eclipse at the very beginning of the season, then there is enough time (30 days) for two more eclipses.
In other words, because the eclipse season (34 days long on average) is longer than the synodic month (one lunation, or the time for the moon to return to a particular phase and about 29.5 days), the moon will be new or full at least two, and up to three, times during the season. Eclipse seasons occur slightly shy of six months apart (successively occurring every 173.31 days - half of an eclipse year), the time it takes the sun to travel from one node to the next along the ecliptic
. If the last eclipse of an eclipse season occurs at the very beginning of a year, it is possible for a total of seven eclipses to occur since there is still time before the end of the year for two full eclipse seasons, each having up to three eclipses.
s.
(The two eclipse seasons above share similarities (lunar or solar centrality and gamma
of each eclipse in the same column) because they are a half saros apart.)
Eclipse
An eclipse is an astronomical event that occurs when an astronomical object is temporarily obscured, either by passing into the shadow of another body or by having another body pass between it and the viewer...
s can occur, due to the 5° inclination of the moon's orbit. Each season lasts for approximately 33 days and repeats just short of six months, thus there are always two full eclipse seasons each year. 2 to 3 eclipses always occur each eclipse season. During the season the inclination of the moon is low, hence the Sun, Moon and Earth become close enough in alignment (syzygy
Syzygy (astronomy)
In astronomy, a syzygy is a straight line configuration of three celestial bodies in a gravitational system. The word is usually used in reference to the Sun, the Earth and either the Moon or a planet, where the latter is in conjunction or opposition. Solar and lunar eclipses occur at times of...
) for an eclipse to occur.
Details
An eclipse season is the only time during which the sun (from the perspective of the earth) is close enough to one of the moon's nodesLunar node
The lunar nodes are the orbital nodes of the Moon, that is, the points where the orbit of the Moon crosses the ecliptic . The ascending node is where the moon crosses to the north of the ecliptic...
to allow for an eclipse
Eclipse
An eclipse is an astronomical event that occurs when an astronomical object is temporarily obscured, either by passing into the shadow of another body or by having another body pass between it and the viewer...
to occur. During the season, whenever there is a full moon a lunar
Lunar eclipse
A lunar eclipse occurs when the Moon passes behind the Earth so that the Earth blocks the Sun's rays from striking the Moon. This can occur only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, a lunar eclipse can only occur the night of a...
eclipse will occur and whenever there is a new moon a solar eclipse
Solar eclipse
As seen from the Earth, a solar eclipse occurs when the Moon passes between the Sun and the Earth, and the Moon fully or partially blocks the Sun as viewed from a location on Earth. This can happen only during a new moon, when the Sun and the Moon are in conjunction as seen from Earth. At least...
will occur. If the sun is close enough to a node, then a total eclipse
Total Eclipse
A total eclipse is an eclipse where either the Sun is entirely covered by the Moon, or the Earth's shadow entirely covers the Moon.Total Eclipse may also refer to:-Music:* Total Eclipse , a Goa trance music group...
will occur. Each season lasts from 31 to 37 days, recurring about every 6 months. At least two (one solar and one lunar, in any order), and at most three eclipses (solar, lunar, then solar again, or vice versa), will occur during every eclipse season. This is because it is about 15 days (a fortnight) between full moon and new moon and vice versa. If there is an eclipse at the very beginning of the season, then there is enough time (30 days) for two more eclipses.
In other words, because the eclipse season (34 days long on average) is longer than the synodic month (one lunation, or the time for the moon to return to a particular phase and about 29.5 days), the moon will be new or full at least two, and up to three, times during the season. Eclipse seasons occur slightly shy of six months apart (successively occurring every 173.31 days - half of an eclipse year), the time it takes the sun to travel from one node to the next along the ecliptic
Ecliptic
The ecliptic is the plane of the earth's orbit around the sun. In more accurate terms, it is the intersection of the celestial sphere with the ecliptic plane, which is the geometric plane containing the mean orbit of the Earth around the Sun...
. If the last eclipse of an eclipse season occurs at the very beginning of a year, it is possible for a total of seven eclipses to occur since there is still time before the end of the year for two full eclipse seasons, each having up to three eclipses.
Visual sequence of two particular eclipse seasons
In each sequence below, each eclipse is separated by a fortnight. The first and last eclipse in each sequence is separated by one synodic month. See eclipse cycleEclipse cycle
Eclipses may occur repeatedly, separated by certain intervals of time: these intervals are called eclipse cycles. The series of eclipses separated by a repeat of one of these intervals is called an eclipse series.- Eclipse conditions :...
s.
| May 26th May 2002 lunar eclipse A penumbral lunar eclipse took place on May 26, 2002, the first of three lunar eclipses in 2002.- Visibility :The beginning of the penumbral phase visible in most of North America except the northeast, Central America, western South America, extreme northeast Russia, eastern Asia, Australia, most... Descending Node (Full Moon) | June 10th Solar eclipse of June 10, 2002 An annular solar eclipse occurred on June 10, 2002. -External links:Photos:*... Ascending Node (New Moon) | June 24th June 2002 lunar eclipse A penumbral lunar eclipse took place on June 24, 2002, the second of three lunar eclipses in 2002. This penumbral eclipse was visibly inperceptible due to the small entry into the southern penumbral shadow.- External links :*... Descending Node (Full Moon) |
|---|---|---|
 |
 |
|
| Penumbral lunar eclipse | Annular solar eclipse | Penumbral lunar eclipse |
| June 1st Solar eclipse of June 1, 2011 A partial solar eclipse occurred on June 1, 2011. This eclipse is the second of four partial solar eclipses in 2011, with the others occurring on January 4, 2011, July 1, 2011, and November 25, 2011.... Descending Node (New Moon) | June 15th June 2011 lunar eclipse A total lunar eclipse took place on June 15, 2011. It was the first of two such eclipses in 2011. The second will occur on December 10, 2011.This was a relatively rare central lunar eclipse, in which the center point of Earth's shadow passes across the Moon. The last time a lunar eclipse was closer... Ascending Node (Full Moon) | July 1st Solar eclipse of July 1, 2011 A partial solar eclipse occurred on July 1, 2011. This is the first solar eclipse of saros series 156, only visible as a partial solar eclipse in a small area south of South Africa and north of Antarctica. At greatest eclipse, the magnitude is just 0.097. It is the first new saros series to begin... Descending Node (New Moon) |
|---|---|---|
 |
||
| Partial solar eclipse | Total lunar eclipse | Partial solar eclipse |
(The two eclipse seasons above share similarities (lunar or solar centrality and gamma
Gamma (solar eclipse)
Gamma of an eclipse describes how centrally the shadow of the moon or earth strikes the other. The distance, when the axis of the shadow cone passes closest to earth or moon's center, is stated as fraction of the equatorial radius of the earth...
of each eclipse in the same column) because they are a half saros apart.)
Two year chart of eclipses (2011 - 2012) demonstrating seasons
| Date | Type (phase) | Time of season !! next eclipse will occur... | |
|---|---|---|---|
| January 4, 2011 | solar (new) | end | next eclipse season |
| ... no eclipses for about 5 months... | |||
| June 1, 2011 | solar (new) | beginning | next full moon |
| June 15, 2011 | lunar (full) | middle | next new moon |
| July 1, 2011 | solar (new) | end | next eclipse season |
| ... no eclipses for about 5 months... | |||
| November 25, 2011 | solar (new) | beginning | next full moon |
| December 10, 2011 | lunar (full) | end | next eclipse season |
| ... no eclipses for about 5 and a half months... | |||
| May 20, 2012 | solar (new) | beginning | next full moon |
| June 4, 2012 | lunar (full) | end | next eclipse season |
| ... no eclipses for about 5 and a half months... | |||
| November 13, 2012 | solar (new) | beginning | next full moon |
| November 28, 2012 | lunar (full) | end | next eclipse season (spring of 2013) |
See also
- Orbit of the Moon
- Eclipse cycleEclipse cycleEclipses may occur repeatedly, separated by certain intervals of time: these intervals are called eclipse cycles. The series of eclipses separated by a repeat of one of these intervals is called an eclipse series.- Eclipse conditions :...
- Lunar nodeLunar nodeThe lunar nodes are the orbital nodes of the Moon, that is, the points where the orbit of the Moon crosses the ecliptic . The ascending node is where the moon crosses to the north of the ecliptic...
- EclipticEclipticThe ecliptic is the plane of the earth's orbit around the sun. In more accurate terms, it is the intersection of the celestial sphere with the ecliptic plane, which is the geometric plane containing the mean orbit of the Earth around the Sun...
- SyzygySyzygy (astronomy)In astronomy, a syzygy is a straight line configuration of three celestial bodies in a gravitational system. The word is usually used in reference to the Sun, the Earth and either the Moon or a planet, where the latter is in conjunction or opposition. Solar and lunar eclipses occur at times of...
- Lunar phaseLunar phaseA lunar phase or phase of the moon is the appearance of the illuminated portion of the Moon as seen by an observer, usually on Earth. The lunar phases change cyclically as the Moon orbits the Earth, according to the changing relative positions of the Earth, Moon, and Sun...
- InclinationInclinationInclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...