The concept of “day” is so obvious to us, people, that we often get surprised when we realize that the length of the day on other planets can be quite different than here on Earth. Perhaps even more shocking thing is, that so far we did’t know how long is a day on Saturn.
Thanks to data collected from the Cassini mission, we have an answer to this long-standing mystery. Saturn spins around its axis for 10 hours, 33 minutes and 38 seconds. The findings are published in the Astrophysical Journal.
Planetary scientists often use magnetic fields to determine the rotation of a planet. If the magnetic field and the rotary axis are not in line, it is possible to calculate the periodic signals in the radio waves that are repeated on a daily basis. On Saturn, however, the magnetic field is almost completely aligned, so it is impossible.
That is why scientists had to approach in a different way. They develop the hypothesis that the rings of the planet are the key to helping them understand how long one day Saturn lasts. As the planet rotates, barely noticeable differences in gravity generate waves within the rings. This is what have unleashed this longstanding conundrum. And, of course, the observations made by the Cassini spacecraft, without which this would not be possible.