<p>A day on Saturn is 10 hours, 32 minutes and 45 seconds long, said a study Wednesday that further demystifies the ringed gas giant.<br /><br /></p>.<p>Saturn's rotation period had long left scientists scratching their heads -- the sixth-furthest planet from our sun has no solid object on its surface to allow easy observation of the speed at which it spins.<br /><br />NASA's Voyager spacecraft had previously used radio measurements to calculate a rotation of 10 hours 39 minutes and 22.4 seconds, while the Cassini space traveller came up with 10 hours 47 minutes and six seconds.<br /><br />The latest calculation, which the study authors believe to be the most accurate yet, was based on measurements of Saturn's gravitational field, and adjusted for the planet's shape and density.<br /><br />To confirm their findings, the team applied the same method to measure, and confirm, the rotation of Saturn's gassy neighbour Jupiter, whose speed was already well-known.<br /><br />"An accurate determination of Saturn's rotation period has important implications for understanding its atmospheric dynamics and internal structure," study co-author Ravit Helled of Israel's Tel Aviv University told AFP by email.<br /><br />Knowledge of the internal structure, in turn, "provides important information on the formation process of gas giant planets".<br /><br />The new measurement implied that Saturn's core was smaller than previously estimated, said Helled.<br /><br />The method may in the future be used to derive the rotation periods of other giant planets.</p>
<p>A day on Saturn is 10 hours, 32 minutes and 45 seconds long, said a study Wednesday that further demystifies the ringed gas giant.<br /><br /></p>.<p>Saturn's rotation period had long left scientists scratching their heads -- the sixth-furthest planet from our sun has no solid object on its surface to allow easy observation of the speed at which it spins.<br /><br />NASA's Voyager spacecraft had previously used radio measurements to calculate a rotation of 10 hours 39 minutes and 22.4 seconds, while the Cassini space traveller came up with 10 hours 47 minutes and six seconds.<br /><br />The latest calculation, which the study authors believe to be the most accurate yet, was based on measurements of Saturn's gravitational field, and adjusted for the planet's shape and density.<br /><br />To confirm their findings, the team applied the same method to measure, and confirm, the rotation of Saturn's gassy neighbour Jupiter, whose speed was already well-known.<br /><br />"An accurate determination of Saturn's rotation period has important implications for understanding its atmospheric dynamics and internal structure," study co-author Ravit Helled of Israel's Tel Aviv University told AFP by email.<br /><br />Knowledge of the internal structure, in turn, "provides important information on the formation process of gas giant planets".<br /><br />The new measurement implied that Saturn's core was smaller than previously estimated, said Helled.<br /><br />The method may in the future be used to derive the rotation periods of other giant planets.</p>