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)
“Stupid word, that. Period. In America it means “full stop” like in punctuation. That’s stupid as well. A period isn’t a full stop. It’s a new beginning. I don’t mean all that creativity, life-giving force, earth-mother stuff, I mean it’s a new beginning to the month, relief that you’re not pregnant, when you don’t have to have a child.”
—Michelene Wandor (b. 1940)