diff --git a/generate/template/astronomy.py b/generate/template/astronomy.py
index 2f6fb793..9e4f029f 100644
--- a/generate/template/astronomy.py
+++ b/generate/template/astronomy.py
@@ -226,6 +226,10 @@ class Time:
 
 class Observer:
     """Represents the geographic location of an observer on the surface of the Earth.
+
+    :param latitude: Geographic latitude in degrees north of the equator.
+    :param longitude: Geographic longitude in degrees east of the prime meridian at Greenwich, England.
+    :param height: Elevation above sea level in meters.
     """
     def __init__(self, latitude, longitude, height=0):
         self.latitude = latitude
@@ -579,6 +583,22 @@ def _CalcMoon(time):
     )
 
 def GeoMoon(time):
+    """Calculates the geocentric position of the Moon at a given time.
+
+    Given a time of observation, calculates the Moon's position as a vector.
+    The vector gives the location of the Moon's center relative to the Earth's center
+    with x-, y-, and z-components measured in astronomical units.
+
+    This algorithm is based on Nautical Almanac Office's <i>Improved Lunar Ephemeris</i> of 1954,
+    which in turn derives from E. W. Brown's lunar theories from the early twentieth century.
+    It is adapted from Turbo Pascal code from the book
+    [Astronomy on the Personal Computer](https://www.springer.com/us/book/9783540672210)
+    by Montenbruck and Pfleger.
+
+    :param time:  The date and time for which to calculate the Moon's position.
+    :return The Moon's position as a vector in J2000 Cartesian equatorial coordinates.
+    :rtype Vector
+    """
     m = _CalcMoon(time)
 
     # Convert geocentric ecliptic spherical coordinates to Cartesian coordinates.
diff --git a/source/python/README.md b/source/python/README.md
index bd1b9f10..90db0c55 100644
--- a/source/python/README.md
+++ b/source/python/README.md
@@ -12,3 +12,27 @@ Observer(self, latitude, longitude, height=0)
 ```
 Represents the geographic location of an observer on the surface of the Earth.
 
+:param latitude: Geographic latitude in degrees north of the equator.
+:param longitude: Geographic longitude in degrees east of the prime meridian at Greenwich, England.
+:param height: Elevation above sea level in meters.
+
+## GeoMoon
+```python
+GeoMoon(time)
+```
+Calculates the geocentric position of the Moon at a given time.
+
+Given a time of observation, calculates the Moon's position as a vector.
+The vector gives the location of the Moon's center relative to the Earth's center
+with x-, y-, and z-components measured in astronomical units.
+
+This algorithm is based on Nautical Almanac Office's <i>Improved Lunar Ephemeris</i> of 1954,
+which in turn derives from E. W. Brown's lunar theories from the early twentieth century.
+It is adapted from Turbo Pascal code from the book
+[Astronomy on the Personal Computer](https://www.springer.com/us/book/9783540672210)
+by Montenbruck and Pfleger.
+
+:param time:  The date and time for which to calculate the Moon's position.
+:return The Moon's position as a vector in J2000 Cartesian equatorial coordinates.
+:rtype Vector
+
diff --git a/source/python/astronomy.py b/source/python/astronomy.py
index d2b97267..33fb3162 100644
--- a/source/python/astronomy.py
+++ b/source/python/astronomy.py
@@ -317,6 +317,10 @@ class Time:
 
 class Observer:
     """Represents the geographic location of an observer on the surface of the Earth.
+
+    :param latitude: Geographic latitude in degrees north of the equator.
+    :param longitude: Geographic longitude in degrees east of the prime meridian at Greenwich, England.
+    :param height: Elevation above sea level in meters.
     """
     def __init__(self, latitude, longitude, height=0):
         self.latitude = latitude
@@ -1893,6 +1897,22 @@ def _CalcMoon(time):
     )
 
 def GeoMoon(time):
+    """Calculates the geocentric position of the Moon at a given time.
+
+    Given a time of observation, calculates the Moon's position as a vector.
+    The vector gives the location of the Moon's center relative to the Earth's center
+    with x-, y-, and z-components measured in astronomical units.
+
+    This algorithm is based on Nautical Almanac Office's <i>Improved Lunar Ephemeris</i> of 1954,
+    which in turn derives from E. W. Brown's lunar theories from the early twentieth century.
+    It is adapted from Turbo Pascal code from the book
+    [Astronomy on the Personal Computer](https://www.springer.com/us/book/9783540672210)
+    by Montenbruck and Pfleger.
+
+    :param time:  The date and time for which to calculate the Moon's position.
+    :return The Moon's position as a vector in J2000 Cartesian equatorial coordinates.
+    :rtype Vector
+    """
     m = _CalcMoon(time)
 
     # Convert geocentric ecliptic spherical coordinates to Cartesian coordinates.