California, Jan 19: The long-standing Mystery of solar system science, the time of Saturn was solved by new data from NASA’s Cassini spacecraft.
According to new findings, the length of a day on Saturn is 10 hours, 33 minutes and 38 seconds. This figure eluded planetary scientists for many years. It turned out, the answer was hidden in the rings.
The year on Saturn is 29 Earth years but the day only lasts for 10:33:38. Saturn, the gas giant has no solid surface with landmarks to track as it rotates, and it has an unusual magnetic field that hides the planet’s rotation rate.
During Cassini's orbits of Saturn, instruments examined the icy, rocky rings in unprecedented detail.
Christopher Mankovich, a graduate student in astronomy and astrophysics at the University of California, Santa Cruz, used the data to study wave patterns within the rings. Malkovich's research, published Jan. 17xx by Astrophysical Journal, describes how he developed models of Saturn's internal structure that would match the rings' waves. That allowed him to track the movements of the interior of the planet – and thus, its rotation.
Scientists often rely on magnetic fields to measure planets' rotation rates. Jupiter's magnetic axis, like Earth's, is not aligned with its rotational axis. So it swings around as the planet rotates, enabling scientists to measure a periodic signal in radio waves to get the rotation rate. However, Saturn is different. Its unique magnetic field is nearly perfectly aligned with its rotational axis.
The idea that Saturn's rings could be used to study the seismology of the planet was first suggested in 1982, long before the necessary observations were possible.
Cassini's mission ended in September 2017, when, low on fuel, it was deliberately plunged into Saturn's atmosphere by the mission team, which wanted to avoid crashing the craft onto the planet's moons, contaminating them.