Saros cycle
E81629
The Saros cycle is an approximately 18-year period after which nearly identical solar and lunar eclipses repeat, due to the alignment of the Earth, Moon, and Sun.
Observed surface forms (1)
| Surface form | Occurrences |
|---|---|
| Saros series | 1 |
Statements (46)
| Predicate | Object |
|---|---|
| instanceOf |
astronomical cycle
ⓘ
eclipse cycle ⓘ periodic phenomenon ⓘ sequence of eclipses ⓘ |
| appliesTo | both solar and lunar eclipse prediction ⓘ |
| basedOnAlignmentOf |
Earth
ⓘ
Moon ⓘ Sun ⓘ |
| causes | eclipse visibility region to move westward each cycle ⓘ |
| causesRepetitionOf |
eclipse characteristics
ⓘ
eclipse geometry ⓘ |
| dependsOn |
anomalistic month
ⓘ
draconic month ⓘ synodic month ⓘ |
| equals |
223 synodic months
ⓘ
239 anomalistic months ⓘ 242 draconic months ⓘ |
| field |
astronomy
ⓘ
celestial mechanics ⓘ |
| hasApproximateDuration |
18 years 11 days 8 hours
ⓘ
6585.3211 days ⓘ |
| hasConsequence |
eclipses in a series evolve from partial to total or annular and back
ⓘ
eclipses in a series gradually shift in latitude ⓘ |
| hasOrigin | ancient Mesopotamian astronomy ⓘ |
| hasProperty |
eclipses occur at similar distance of Moon from Earth
ⓘ
eclipses occur at similar node ⓘ eclipses occur at similar time of year ⓘ |
| hasSubConcept |
Saros cycle
self-linksurface differs
ⓘ
surface form:
Saros series
|
| hasTypicalLength | about 12 to 13 centuries ⓘ |
| hasUncertainty | about 8 hours shift per cycle ⓘ |
| implies |
similar eclipse duration
ⓘ
similar eclipse magnitude ⓘ similar eclipse path on Earth ⓘ |
| isDiscussedIn |
astronomy textbooks
ⓘ
eclipse catalogs ⓘ |
| nameUsedIn | modern eclipse prediction ⓘ |
| precedes | Inex cycle ⓘ |
| relatedTo |
Metonic cycle
ⓘ
Tritos cycle ⓘ |
| relatesTo |
lunar eclipses
ⓘ
solar eclipses ⓘ |
| repetitionOf |
similar lunar eclipses
ⓘ
similar solar eclipses ⓘ |
| usedFor | predicting eclipses ⓘ |
| wasAdoptedBy | Greek astronomers ⓘ |
| wasKnownTo |
Babylonians
ⓘ
surface form:
Babylonian astronomers
|
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Saros series