The lunar nodes are the points where the moon's orbit crosses the ecliptic. The North (or ascending) node is where the Moon crosses to the North of the ecliptic; the South (or descending) node where it crosses to the South.

The lunar nodes are of major significance in vedic astrology, and are considered to a limited degree in western astrology. Usually only the North node is marked in astrological charts, as the South node is by definition always 180° removed—i.e., located at the exact opposite point in the chart.

Solar eclipses occur when a node coincides with the new moon; lunar eclipses when a node coincides with the full moon.