month
A period of time connected with the motion of the Moon
around Earth. The familiar calendar (or
civil) month is an artificial unit consisting of a whole number of days.
For astronomical purposes there are several other types of month.
- Synodic month or lunar month
The average interval from one new Moon to the next
– 29.53059 days
- Anomalistic month
The interval in which the Moon passes from perigee
to perigee – 27.55464 days
- Sidereal month
The interval in which the Moon passes from a fixed
position with respect to the stars back to the
same position – 27.32166 days
- Draconic month or nodal month
The interval between successive passages of the Moon
through its ascending node
- Tropical month
The interval between successive passages of the Moon
through the vernal equinox – a
mean
of 27.21222 days
Related categories
CELESTIAL
MECHANICS UNITS
Also on this site: Encyclopedia
of Alternative Energy & Sustainable Living
Encyclopedia
of History
BACK TO TOP
|