After decades of uncertainty, scientists have finally figured out the length of a day on Saturn.
Saturn’s peculiar magnetic field and landmark-free surface have long stood in the way of scientists’ ability to determine its rotation rate.
But, thanks to Cassini data, they’ve now solved the mystery.
Vibrations picked up by particles in the planet’s rings have provided a window into the movement of Saturn’s interior for the first time, revealing a day on the icy planet lasts just 10 hours, 33 minutes and 38 seconds.
According to a new study published in the Astrophysical Journal, the ring particles respond to vibrations within Saturn much like a seismometer might to an earthquake.
This gives rise to measurable wave patterns.
‘Particles throughout the rings can’t help but feel these oscillations in the gravity field,’ said Christopher Mankovich, a graduate student at UC Santa Cruz.
‘At specific locations in the rings these oscillations catch ring particles at just the right time in their orbits to gradually build up energy, and that energy gets carried away as an observable wave.’
Previous efforts to narrow down the Saturn day estimated it to be 10 hours, 39 minutes, and 23 seconds based on what was known about its magnetic field from radio signals captured by the Voyager spacecraft in the 1980s.
Others, based on Cassini data, suggested it could fall anywhere between 10 hours and 36 minutes to 10 hours and 48 minutes.