After years of research, scientists have determined the age of Saturn’s famous rings, and the results show they were formed much more recently than the planet itself. The rings are now believed to be no more than 400 million years old, which is a mere fraction of the planet’s age of 4.5 billion years. This discovery suggests that the formation of the rings happened much later than was previously thought, according to a team of US scientists who studied the dust surrounding the planet.
Professor Sascha Kempf, the lead author of the study, compares the rings to the carpet in your home. Much like dust settling on a clean carpet over time, Saturn’s rings seem to have accumulated debris over time. This research answered a question that Scottish physicist James Clerk Maxwell first posed when he believed that Saturn’s rings consisted of countless particles. The Maxwell Gap, which is within Saturn’s C ring, is named after him.
Before this discovery, there were many theories about the formation of Saturn’s rings. Some researchers believed they were self-formed, while others thought they were created by the debris of an unstable moon that exploded or ice, rocks, and dust left by a comet that collided with the satellite. The new findings established a definitive age for the rings while leaving other questions, such as their origin, unanswered.
To analyze the accumulation of dust, Professor Kempf and her colleagues studied cosmic dust grains that had originated from beyond the planet’s close neighbourhood between 2004 and 2017. They used the state-of-the-art Cosmic Dust Analyzer, an instrument aboard NASA’s Cassini spacecraft. Over 13 years, the researchers collected just 163 grains, which were enough to suggest that the accumulation of dust on the rings could be a relatively short-term phenomenon.
While the age of Saturn’s rings has now been established, the scientists admit that their discovery doesn’t solve the mystery of how the rings formed. Nevertheless, knowing their age is a critical step forward in humanity’s understanding of the universe, and it is the result of years of scientific research.