Syzygy

The alignment of three celestial bodies—typically the Earth, Moon, and Sun—along a straight line, often resulting in phenomena such as tides, eclipses, or new and full moons.

Syzygy refers to a specific astronomical alignment where three celestial bodies, most commonly the Earth, Moon, and Sun, are positioned in a straight line. This alignment occurs during the new moon and full moon phases. In a marine context, syzygy is significant because it directly influences tidal forces. When the Moon and Sun are aligned with the Earth, their gravitational pulls combine to produce higher than average high tides and lower than average low tides, known as spring tides. These spring tides are not related to the season but to the ‘springing forth’ of the tide during syzygy. Conversely, when the Moon and Sun are at right angles relative to the Earth, neap tides occur, which are less extreme. Mariners, harbour authorities, and coastal planners monitor syzygy events to anticipate tidal extremes, which can affect navigation, mooring, dredging operations, and coastal flooding risks. Understanding syzygy is essential for accurate tidal predictions and safe marine operations.