The rotation period of an astronomical object is the time that it takes to complete one revolution around its axis of rotation relative to the background stars. It differs from the planet's solar day, which includes an extra fractional rotation needed to accommodate the portion of the planet's orbital period during one day.
Read more about Rotation Period: Measuring Rotation, Earth, Rotation Period of Selected Objects
Famous quotes containing the words rotation and/or period:
“The lazy manage to keep up with the earth’s rotation just as well as the industrious.”
—Mason Cooley (b. 1927)
“His singing carried me back to the period of the discovery of America ... when Europeans first encountered the simple faith of the Indian. There was, indeed, a beautiful simplicity about it; nothing of the dark and savage, only the mild and infantile. The sentiments of humility and reverence chiefly were expressed.”
—Henry David Thoreau (1817–1862)