Sidereal Rotation Period of Saturn
| Value | 38,361.6 s |
| Status | Conventional / typical value |
| Source | NASA NSSDC Planetary Fact Sheet, Saturn (sidereal rotation period, System III, 10.656 h); ring seismology gives ≈10.561 h (Mankovich et al. 2019) |
| Categories | Astronomicalsolar-systemplanets |
| Planck time | 7.1155338e+47 tP |
| attosecond | 3.8361600e+22 as |
| femtosecond | 3.8361600e+19 fs |
| picosecond | 3.8361600e+16 ps |
| nanosecond | 38,361,600,000,000 ns |
| shake | 3,836,160,000,000 shake |
| microsecond | 38,361,600,000 μs |
| millisecond | 38,361,600 ms |
| second | 38,361.6 s |
| minute | 639.36 min |
| hour | 10.656 h |
| sidereal day | 0.44521563 sd |
| day | 0.444 d |
| week | 0.063428571 wk |
| fortnight | 0.031714286 fn |
| month | 0.014587569 mo |
| year | 0.0012156057 yr |
| decade | 0.00012156057 dec |
| century | 0.000012156057 cent |
| millennium | 0.0000012156057 mil |
| megayear | 1.2156057e-09 Myr |
| eon | 1.2156057e-12 eon |
Learning zone
Saturn's rotation period is the least certain basic fact about any planet, and honesty requires saying so. The value here, 10 h 39.4 m, is the Voyager-era System III convention, read from periodic radio emission assumed to rotate with the magnetic field. But Saturn's field is almost perfectly aligned with its spin axis — unique in the solar system — so it sweeps no lighthouse beam, and Cassini found the radio period actually drifts by minutes over years and differs between hemispheres: it cannot be the interior's true rotation.
The best modern estimate comes from an unexpected instrument: the rings. Oscillations inside Saturn launch spiral density waves at precise resonant locations, letting the rings act as a seismograph; reading them gives an interior rotation near 10 h 33 m 38 s, about six minutes faster than System III. The NSSDC convention is retained here because published Saturn data are referenced to it — but treat the last digits as convention, not knowledge.