Ask A Scientist© Astronomy Archive

Question:  How fast does the earth and moon rotate?
dewayne t halfen

Answer:  The Moon rotates once in about 27.32 days, and its radius is 1080 miles 
or 1738 km. The rotational speed starts at zero at either geographic pole (the
two places where the axis of rotation intersects the surface) and increases (but 
not at a constant rate) as you head toward the lunar equator, where it reaches i ts maximum of
about 10.3 mi/hr (or 16.7 km/hr). Pretty slow!
By contrast, the Earth rotates once in 24 hours, and its (equatorial) radius is
3,963 miles (6,378 km). As with the Moon, the rotational speed starts at zero at 
either geographic pole and increases as you head toward the equator, where it
reaches its maximum of about 1038 mi/hr (1669 km/hr). At 45 degrees north or south latitude, the
rotational speed is about 0.7 of this maximum speed.
Rcwinther