Saturn's rings are the symbol of Saturn, but when did they form?New data from NASA's Cassini spacecraft suggests that Saturn's rings may have formed much later than Saturn itself, between 10 million and 100 million years ago, roughly the age of the dinosaurs on earth.
Saturn was formed about 4.5 billion years ago.There are clues that its ring system came later, but how much later?
To determine the age of Saturn's rings, scientists need to measure their mass.In the early 1980s, researchers used cassini and voyager spacecraft to make remote sensing measurements of Saturn.In 2017, before cassini's heroic sacrifice, as its fuel continued to run out, it made 22 dives between Saturn and its rings, sending the spacecraft into Saturn's gravitational field.There, it can feel the gravitational pull of Saturn and its rings;Radio signals from NASA's deep space network and the European space agency's antenna to cassini communicate the spacecraft's speed and acceleration.
Once scientists know how much gravity affects cassini, they can determine the mass of Saturn and its rings.
"Only during cassini's closest approach to Saturn have our collected measurements enabled us to make this new discovery," said study author luciano ice of the university of Rome in Italy.With this work, cassini has achieved its basic goal: not only to determine the quality of the rings, but also to use this information to improve the model and determine the ring's age.
Scientists have long known the relationship between the mass of Saturn's rings and their age: the lower the mass, the younger the rings, because for a longer period the bright, mostly icy rings would be stained and dimmed by interplanetary debris.The new, more precise mass data allows scientists to more accurately calculate the age of Saturn's rings, results published online in the latest edition of the journal science.
Scientists will continue to study how Saturn's rings formed.In addition, the new evidence that Saturn's rings are younger adds to the evidence that the rings came from a comet.The theory is that the comet was so close to Saturn that it was torn apart by the planet's gravity, or events that caused an earlier generation of ice moons to disintegrate, forming rings.