Exeligmos
Encyclopedia
An exeligmos is a period of 54 years, 33 days that can be used to predict successive eclipse
s with similar properties and location. For a solar eclipse
, every exeligmos a solar eclipse of similar characteristics will occur close to the eclipse before it. For a lunar eclipse
the same part of the earth will view an eclipse that is very similar to the one that occurred one exeligmos before it (see main text for visual examples). It is an eclipse cycle
that is a triple saros (3 saros long), with the advantage that it has nearly an integer number of days so the next eclipse will be visible at locations and times near the eclipse that occurred one exeligmos earlier. In contrast, each saros, an eclipse occurs about 8 hours later in the day or about 120° to the west of the eclipse that occurred one saros earlier.
was able to predict the dates of consecutive exeligmos.
The exeligmos is 669 synodic months (every eclipse cycle must be an integer number of synodic months), 725 draconic months (which ensures the sun and moon are in alignment during the new moon), and almost exactly 716 anomalistic months (ensuring the moon is at the same point of its elliptic orbit). The first two factors make this a long lasting eclipse series. The latter factor is what makes each eclipse in an exeligmos so similar. The near integer number of anomalistic months ensures that the apparent diameter of the moon will be nearly the same with each successive eclipse. The fact that it is almost exactly 19,756 days ( a whole integer) ensures each successive eclipse in the series occurs very close to the previous eclipse in the series.
Because it is over a month longer than a calendar year, the path of each eclipse one exeligmos apart is roughly 600 miles away from the previous one. The sun's apparent diameter also changes significantly in one month, affecting the length and width of a solar eclipse.
. Each eclipse occurs at roughly the same longitude but moves about 5-15 degrees in latitude with each successive cycle.
of the earth.
of the exeligmos above. Notice how each eclipse falls on a different side of the earth (120 degrees 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 with similar properties and location. For 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...
, every exeligmos a solar eclipse of similar characteristics will occur close to the eclipse before it. For a lunar eclipse
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...
the same part of the earth will view an eclipse that is very similar to the one that occurred one exeligmos before it (see main text for visual examples). It is an eclipse cycle
Eclipse 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 :...
that is a triple saros (3 saros long), with the advantage that it has nearly an integer number of days so the next eclipse will be visible at locations and times near the eclipse that occurred one exeligmos earlier. In contrast, each saros, an eclipse occurs about 8 hours later in the day or about 120° to the west of the eclipse that occurred one saros earlier.
Details
The exeligmos was known by the Greeks as early as 100 BC. A clock they made, called the Antikythera mechanismAntikythera mechanism
The Antikythera mechanism is an ancient mechanical computer designed to calculate astronomical positions. It was recovered in 1900–1901 from the Antikythera wreck. Its significance and complexity were not understood until decades later. Its time of construction is now estimated between 150 and 100...
was able to predict the dates of consecutive exeligmos.
The exeligmos is 669 synodic months (every eclipse cycle must be an integer number of synodic months), 725 draconic months (which ensures the sun and moon are in alignment during the new moon), and almost exactly 716 anomalistic months (ensuring the moon is at the same point of its elliptic orbit). The first two factors make this a long lasting eclipse series. The latter factor is what makes each eclipse in an exeligmos so similar. The near integer number of anomalistic months ensures that the apparent diameter of the moon will be nearly the same with each successive eclipse. The fact that it is almost exactly 19,756 days ( a whole integer) ensures each successive eclipse in the series occurs very close to the previous eclipse in the series.
Because it is over a month longer than a calendar year, the path of each eclipse one exeligmos apart is roughly 600 miles away from the previous one. The sun's apparent diameter also changes significantly in one month, affecting the length and width of a solar eclipse.
Solar exeligmos example
Here is a comparison of two total solar eclipses one exeligmos apart:| March 7, 1970 Solar eclipse of March 7, 1970 The total solar eclipse of March 7, 1970 was visible across all of North America and Central America. Totality was visible across southern Mexico and across the southeast coast of the United States and Canada. Greatest eclipse occurred over Mexico and lasted up to 3 minutes and 28 seconds... |
April 8, 2024 Solar eclipse of April 8, 2024 A total solar eclipse will take place on April 8, 2024, visible as a partial eclipse across North America and Central America. With a magnitude of 1.0566, its longest duration of totality will be of four minutes and 28 seconds near the town of Nazas, Durango, Mexico, and the nearby city of Torreón,... |
|
| Path Map (total eclipse is blue path) (green lines represent limits of partial eclipse) |
||
| Duration | 3 minutes 28 seconds | 4 minutes 28 seconds |
| Max width of total eclipse path | 153 kilometers | 199 kilometers |
| Latitude of greatest eclipse | 18° North | 25° North |
| Time of greatest eclipse (UTC) | 17:38 | 18:17 |
Lunar exeligmos example
Here is a comparison of two total lunar eclipses one exeligmos apart:| February 9, 1990 February 1990 lunar eclipse A total lunar eclipse took place on February 9, 1990, the first of two lunar eclipses in 1990.- Visibility :It was visible from all of Africa, Europe, Asia and Australia. The eclipse is sighted over the Philippines since the one happened on February 20, 1989.- External links :... |
March 13, 2044 March 2044 lunar eclipse A total lunar eclipse will take place on March 13, 2044.... |
|
| Path Map |
 |
 |
| Visibility (side of earth eclipse is visible from) |
 |
|
| Duration (Partial eclipse) | 204 minutes | 209 minutes |
| Time of greatest eclipse (UTC) | 19:12 | 19:38 |
Sample series of solar exeligmos
Exeligmos table of solar saros 136Solar Saros 136
Solar Saros 136 is currently producing the longest total solar eclipses. It produced the 6 longest total eclipses of the 20th century, 3 of them over 7 minutes long. It also produced the longest total eclipse of the 21st century at 6 min 39 sec, and overall will produce the centuries 3 longest...
. Each eclipse occurs at roughly the same longitude but moves about 5-15 degrees in latitude with each successive cycle.
| Saros | Member | Date | Time (Greatest) UTC |
Type | Location Lat,Long |
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... |
Mag. Magnitude of eclipse The magnitude of eclipse or geometric magnitude is the fraction of the diameter of the eclipsed body which is in eclipse. This applies to both solar eclipses and lunar eclipses. During a partial or annular eclipse the magnitude of the eclipse is always between 0.0 and 1.0, while during a total... |
Width (km) |
Duration (min:sec) |
Ref |
|---|---|---|---|---|---|---|---|---|---|---|
| 136 | 3 | July 5, 1396 | 19:37:40 | Partial | 63.9S 147.2W | |||||
| 0.3449 | http://eclipse.gsfc.nasa.gov/5MCSEmap/1301-1400/1396-07-05.gif | |||||||||
| 136 | 6 | August 7, 1450 | 16:48:49 | Partial | 61.8S 132.8W | |||||
| 0.756 | http://eclipse.gsfc.nasa.gov/5MCSEmap/1401-1500/1450-08-07.gif | |||||||||
| 136 | 9 | September 8, 1504 | 15:12:15 | Annular | 55.3S 102.6W | |||||
| 0.9924 | 83 | 0m 32s | http://eclipse.gsfc.nasa.gov/5MCSEmap/1501-1600/1504-09-08.gif | |||||||
| 136 | 12 | October 11, 1558 | 14:58:55 | Annular | 56.5S 90.3W | |||||
| 0.9971 | 18 | 0m 12s | http://eclipse.gsfc.nasa.gov/5MCSEmap/1501-1600/1558-10-11.gif | |||||||
| 136 | 15 | November 22, 1612 | 16:04:35 | Hybrid | 65.7S 98.4W | |||||
| 1.0002 | 1 | 0m 1s | http://eclipse.gsfc.nasa.gov/5MCSEmap/1601-1700/1612-11-22.gif | |||||||
| 136 | 18 | December 25, 1666 | 17:59:16 | Hybrid | 71.6S 98.3W | |||||
| 1.0058 | 30 | 0m 24s | http://eclipse.gsfc.nasa.gov/5MCSEmap/1601-1700/1666-12-25.gif | |||||||
| 136 | 21 | January 27, 1721 | 20:05:11 | Total | 64S 102.4W | |||||
| 1.0158 | 79 | 1m 7s | http://eclipse.gsfc.nasa.gov/5MCSEmap/1701-1800/1721-01-27.gif | |||||||
| 136 | 24 | March 1, 1775 | 21:39:20 | Total | 47.9S 124.8W | |||||
| 1.0304 | 139 | 2m 20s | http://eclipse.gsfc.nasa.gov/5MCSEmap/1701-1800/1775-03-01.gif | |||||||
| 136 | 27 | April 3, 1829 | 22:18:36 | Total | 28.5S 142.6W | |||||
| 1.0474 | 192 | 4m 5s | http://eclipse.gsfc.nasa.gov/5MCSEmap/1801-1900/1829-04-03.gif | |||||||
| 136 | 30 | May 6, 1883 Solar eclipse of May 6, 1883 A total solar eclipse occurred on May 6, 1883. The path of totality fell across the southern Pacific Ocean with no major landfall. Partiality was visible from far eastern Australia at sunrise, and New Zealand, as well as western South America and southern Mexico near sunset... |
21:53:49 | Total | 8.1S 144.6W | |||||
| 1.0634 | 229 | 5m 58s | http://eclipse.gsfc.nasa.gov/5MCSEmap/1801-1900/1883-05-06.gif | |||||||
| 136 | 33 | June 8, 1937 Solar eclipse of June 8, 1937 A total solar eclipse occurred on June 8, 1937. The path of totality crossed the pacific ocean starting in Micronesia, and ending at sunset in western South America.-References:*... |
20:41:02 | Total | 9.9N 130.5W | |||||
| 1.0751 | 250 | 7m 4s | http://eclipse.gsfc.nasa.gov/5MCSEmap/1901-2000/1937-06-08.gif | |||||||
| 136 | 36 | July 11, 1991 Solar eclipse of July 11, 1991 A total solar eclipse occurred on July 11, 1991. Totality beginning over the Pacific Ocean and Hawaii moving across Mexico, down through Central America and across South America ending over Brazil. It lasted for 6 minutes and 53 seconds at the point of maximum eclipse... |
19:07:01 | Total | 22N 105.2W | |||||
| 1.08 | 258 | 6m 53s | http://eclipse.gsfc.nasa.gov/5MCSEmap/1901-2000/1991-07-11.gif | |||||||
| 136 | 39 | August 12, 2045 Solar eclipse of August 12, 2045 A total solar eclipse will occur on August 12, 2045. It will be the fourth longest eclipse of the 21st century. It will be visible throughout much of the continental United States, with a path of totality running through northern California, Nevada, Utah, Colorado, Kansas, Oklahoma, Arkansas,... |
17:42:39 | Total | 25.9N 78.5W | 0.2116 | 1.0774 | 256 | 6m 6s | http://eclipse.gsfc.nasa.gov/5MCSEmap/2001-2100/2045-08-12.gif |
| 136 | 42 | September 14, 2099 Solar eclipse of September 14, 2099 A total solar eclipse will occur on September 14, 2099. - Visibility :It will begin at sunrise off the western coast of Canada, and move eastern across Canada and the northern states of the United States and end in the Atlantic ocean... |
16:57:53 | Total | 23.4N 62.8W | 0.3942 | 1.0684 | 241 | 5m 18s | http://eclipse.gsfc.nasa.gov/5MCSEmap/2001-2100/2099-09-14.gif |
| 136 | 45 | October 17, 2153 | 17:12:18 | Total | 18.8N 65.7W | 0.5259 | 1.056 | 214 | 4m 36s | http://eclipse.gsfc.nasa.gov/5MCSEmap/2101-2200/2153-10-17.gif |
| 136 | 48 | November 20, 2207 | 18:30:26 | Total | 15.8N 87.8W | 0.6027 | 1.0434 | 180 | 3m 56s | http://eclipse.gsfc.nasa.gov/5MCSEmap/2201-2300/2207-11-20.gif |
| 136 | 51 | December 22, 2261 | 20:38:50 | Total | 16.1N 124.2W | 0.636 | 1.0337 | 147 | 3m 17s | http://eclipse.gsfc.nasa.gov/5MCSEmap/2201-2300/2261-12-22.gif |
| 136 | 54 | January 25, 2316 | 23:05:17 | Total | 21.4N 166W | 0.6526 | 1.0282 | 126 | 2m 42s | http://eclipse.gsfc.nasa.gov/5MCSEmap/2301-2400/2316-01-25.gif |
| 136 | 57 | February 27, 2370 | 1:07:02 | Total | 33.2N 157E | 0.6865 | 1.0262 | 121 | 2m 17s | http://eclipse.gsfc.nasa.gov/5MCSEmap/2301-2400/2370-02-27.gif |
| 136 | 60 | March 31, 2424 | 2:10:10 | Total | 51.3N 131.9E | 0.7652 | 1.0254 | 133 | 1m 55s | http://eclipse.gsfc.nasa.gov/5MCSEmap/2401-2500/2424-03-31.gif |
| 136 | 63 | May 3, 2478 | 1:55:59 | Total | 75.7N 107.7E | 0.9034 | 1.0218 | 176 | 1m 20s | http://eclipse.gsfc.nasa.gov/5MCSEmap/2401-2500/2478-05-03.gif |
| 136 | 66 | June 5, 2532 | 0:28:58 | Partial | 67.5N 1.3E | 1.0962 | 0.8224 | http://eclipse.gsfc.nasa.gov/5MCSEmap/2501-2600/2532-06-05.gif | ||
| 136 | 69 | July 7, 2586 | 22:07:07 | Partial | 64.5N 7.2E | 1.327 | 0.3957 | http://eclipse.gsfc.nasa.gov/5MCSEmap/2501-2600/2586-07-07.gif |
Solar Exeligmos Animation
Here is an animation of an exeligmos series. Note the similar paths of each total eclipse, and how they fall close to the same longitudeLongitude
Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is an angular measurement, usually expressed in degrees, minutes and seconds, and denoted by the Greek letter lambda ....
of the earth.
Solar Saros Animation (for comparison)
This next animation is from the entire saros seriesSolar Saros 136
Solar Saros 136 is currently producing the longest total solar eclipses. It produced the 6 longest total eclipses of the 20th century, 3 of them over 7 minutes long. It also produced the longest total eclipse of the 21st century at 6 min 39 sec, and overall will produce the centuries 3 longest...
of the exeligmos above. Notice how each eclipse falls on a different side of the earth (120 degrees apart).
See also
- Solar eclipseSolar eclipseAs 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...
- 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 :...
- saros
- Full moon cycleFull moon cycleThe full moon cycle is a cycle of about 14 lunations over which full moons vary in apparent size and age . The sequence is*Full moon big - *Full moon young -...