Orbital period

The Drakonitische period refers to the time between satellites of the repeated passing of the same node.

The name derives from the Dragon Point (Latin draco), the old word for the lunar nodes. Only the coincidence of one of the nodes with full or new moon, a moon or solar eclipse is possible.

For the Earth's moon is called the averaged value of the time between two passes through the same lunar node Drakonitischer month. It is used to calculate the Saros ( the time period after which solar and lunar eclipses repeat ).

A drakonitisches year - at least for the earth - not specified: A medium value can not be defined, because the ecliptic is the middle level of the Earth's orbit. In fact, the true earth's orbit from the ecliptic differs from, and the " node of the orbit of the earth " is the true vernal equinox, and the corresponding period of the solar year.

For the other planets could be - in the broader sense of the term as years orbital period - specify a drakonitisches year, as their inclination is different from zero. But because the drakonitische period can be seen in the context of eclipses, the mention of which is not very interesting.