WASHINGTON: Saturn’s rings are younger than scientists thought and appeared within the last 10 to 100 million years, according to research published Thursday based on findings from NASA’s Cassini spacecraft. The sixth planet from the Sun formed about 4.5 billion years ago, along with the rest of the planets in our solar system, and spent the bulk of its existence without the characteristic rings it is known for today. Astronomers have long believed the rings could be young, and perhaps formed by collisions between the moons of Saturn or by a comet that shattered in close proximity to the planet. Some of these answers have come into sharper focus because of Cassini, an unmanned US-European probe that launched in 1997 and ended in 2017 with a planned death plunge into Saturn’s surface.