Using new spacecraft data from NASA, Cassini, researchers they believe they have decided a long-standing mystery of the Solar System: the duration of one day of Saturn, who it turned out that it was 10 hours, 33 minutes and 38 seconds.
That it was a mystery to planetary scientists for decadesbecause the gas giant No solid surface with reference points to be watched while spinning, and has an unusual magnetic field that hides the speed of rotation of the planet.
During Saturn's orbit of Cassini, the instruments examined the frozen and rocky rings with unseen details. Christopher Mankovic, a graduate student of astronomy and astrophysics in Santa Cruz, He used the data to study the models of the otherinside the rings.
His work determined that the rings to respond to vibrations in the planet itself, acting similarly to seismometers used to measure the motion caused by earthquakes. Saturn's interior vibrates at frequencies that cause variations in the gravitational field. Rings, however, detect those movements in the field.
"Particles on the rings they can not help to feel these oscillations in the field of gravity, "said Mankovic." At specific locations, these oscillations capture the ring particles at the right moment of their orbits, to accumulate energy gradually, and that energy is worn as a visible wave. "
The research by Mankovich, published on January 17 from the Astrophysical Journal, describes how he developed models of the inner structure of Saturn which coincided with the rings of the rings. This allowed him to follow the movement of the interior of the planet, and thus its rotation.
Rate of turnover from 10:33:38 The analysis is a few minutes faster than the previous estimates in 1981, which were based on radio signals from NASA's Voyager spacecraft.
Analysis of Voyager data, which He estimated that the day is 10:39:23, was based on information about the magnetic field. Cassini also used magnetic field data, but previous estimates ranged between 10:36 and 10:48.