Saturn: Astronomers finally know what time it is on the planet

Walking on Saturn would be impossible. Because the gas giant has no solid surface. Astronomers have a problem with this: they can not find a landmark where they can see how fast the planet is spinning around itself. Even the unusual magnetic field made calculations so far difficult.

So far no one has been able to say with certainty how long a day lasts on the second largest planet of our solar system. Now, researchers report having finally found an answer: a day on Saturn lasts ten hours, 33 minutes and 38 seconds.


New data from the Saturn probe "Cassini" had put the researchers on the right track. The unmanned probe was launched in October 1997 and reached the Ring Planet in July 2004. For about 13 years, "Cassini" made its tracks through the mesmerizing Saturn system, discovering new rings and moons, revealing many of the secrets of the second largest planet in the solar system with its large rings and dozens of moons.

In 2017, "Cassini" ran out of fuel, and the probe burned up in the atmosphere of the gas planet. Previously, however, it had sent enormous amounts of data towards Earth, which are still being evaluated. As a result, researchers know, for example, how Saturn sounds.

"Cassini" also get detailed shots of the more than 100,000 rings that surround Saturn. They consist mainly of water ice and rocks. The outer ones have a diameter of almost one million kilometers. They are surprisingly thin, the thickest measures only about a hundred meters.

An astronomy student from Santa Cruz, Christopher Mankovich, took a closer look at the images of the Saturn probe and found that the rings react to vibrations inside the planet, much like seismometers that measure earthquakes. This enabled Makovich to calculate how fast the gas giant is turning around itself, as he reports with colleagues in the journal "Astrophysical Journal".

Faster than expected

The analysis shows that Saturn turns faster than previously thought. The most recent calculations from the year 1981 had assumed a rotational speed of ten hours, 39 minutes and 23 seconds. But even then, the researchers knew that the result is inaccurate, because they went back to calculations of the magnetic field. And that is extremely unusual with Saturn, because it runs almost exactly parallel to the axis of rotation - unique in our solar system.

"The researchers used the rings to look inside Saturn, and this fundamental insight came out," praises Linda Spilker, scientist of the "Cassini" project. "The answer lay in the rings."

In the video: Saturn loses his rings

Rotational speed knowledge is not the only groundbreaking news from the gas giant. According to recent research by NASA, the rings around Saturn are much younger than previously thought. According to them, they first came into being about a hundred million years ago - at a time when dinosaurs lived on Earth. The planet itself is much older, about 4.5 billion years.

According to popular theory, once upon a time a moon could have come too close to the planet and been destroyed by gravity. Also, a collision of two Saturn moons is suspected as the cause of the formation of the rings. Since then, the rings are crumbling - researchers expect that they will be gone in about 300 million years.