When we think of Saturn, the sixth planet in our Solar System , it is unthinkable to imagine it without its rings. The first time they were observed was in July 1610 by the famous Galileo Galile. However, unlike what was thought, these characteristic complements have not always been there.
As detailed in an article in the journal Science, the annual meeting of the American Geophysical Union (AGU) has reported that, thanks to the latest observations from NASA’s Cassini spacecraft, it has been discovered that this system of planetary rings it did not exist until a few hundred million years ago. Considering that the universe is approximately 13,500 million years old, it can be considered that the age of the rings is extremely young: practically a newborn in our Solar System.
To give us an idea, if Galileo had existed during the age of the dinosaurs and look at the sky through his telescope, he could not have distinguished Saturn as we know it today.
Thanks to Cassini, we can assure that rings did not exist in the early days of the Solar System 4.5 billion years ago, as scientists believed.
Two evidences have supported this affirmation.
The main test, and the one that has been announced for the moment, comes from the mass of the rings . Due to the opaque and dense appearance shown by the images of Saturn’s primary ring, it was speculated that they had been created next to the planet. However, having a lower weight than originally estimated, their age is also lower than previously thought.
When Cassini began to open the gap between Saturn and its rings during its last voyages, the team could distinguish the gravitational attraction of the rings and, therefore, its mass. Luciano Iess , a planetary scientist at Sapienza University in Rome, says that if the theories that relate mass to age are correct, “this is the clear indication that the rings did not form together with Saturn.”
A phenomenon that remains unanswered
Since in 1655 Christiaan Huygens discovered that there were not three bodies but four around Saturn , an attempt has been made to find an explanation of how these rings were formed. However, the discussion continues.
Some of the hypotheses that are shuffled are from the possibility of a comet or asteroid impacting an icy moon, throwing its remains towards the orbit of Saturn; even the idea that they were created from the remains of planets like Pluto.
Scientists argue that the Cassini results actually verify that the rings are young, perhaps less than 200 million years old . But for now, they have only begun to study how the collision could have formed rings.
Jeff Cuzzi , ring specialist at NASA’s Ames Research, says, “Part of the reluctance for everyone to jump from this bridge into the unknown is that we have not had any kind of feasible explanation.” According to him it ‘s time for new ideas, “the solar system could be full of surprises like this one”.