Astronomers have long observed that Saturn’s rings appear to be raining down onto its planet in large quantities. This phenomenon occurs due to space rocks colliding with them or solar radiation slightly disturbing ring particles and electrifying them, creating the “rain.”
The Origin of the Rings
The rings of Saturn are both beautiful and mysterious; scientists remain divided as to when and how these bangles of rock and ice first formed around Saturn or how they have developed into what we see today. A recent study suggests that they may even be much younger than previously assumed.
The findings, published Thursday in Science, draw upon observations made by NASA’s Cassini spacecraft during its 13-year mission. Astronomers used enhanced transmissions from Cassini flybys to measure exactly how much ring material was falling into Jupiter and being vaporized – providing them with an even clearer picture of how their rings might eventually vanish than had they relied solely on Voyager observations from the 1980s.
According to researchers, some 200 to 100 million years ago a large icy body, perhaps a comet or even one of Saturn’s moons, became unstable and passed too close to Saturn for its gravity to handle, becoming unstable and disintegrating into an unpredictable stream of icy fragments that eventually formed Saturn’s iconic rings system.
However, there remains one problem: Saturn’s rings seem too young and big to have formed at its birth; rather they may have resulted from the breakup of an older comet or moon later in its evolution, according to Jack Wisdom of Massachusetts Institute of Technology’s Jack Wisdom’s research for Wall Street Journal.
Noteworthy is the presence of gaps within Saturn’s rings where particle density drastically declines; these are areas which experience “ring rain”, filling an Olympic-size pool every half-hour according to NASA estimates. Researchers still don’t fully understand why this happens but speculate it might have something to do with particles being caught up by Saturn’s magnetic field and being swept away, leaving gaps to form; should erosion continue at its current rate, these materials might no longer form enough moonlets which orbit these bangles.
The Age of the Rings
Saturn boasts the grandest rings in our solar system. Extending over 280,000 km from its orbit and wide enough to fit six Earths together in one row, they span across over 280,000 kilometers from planet to ring and wide enough for six Earths in line – yet astronomers recently discovered that these iconic rings are dissolving much faster than anticipated.
Ring rain is the result of Saturn’s orbit around the Sun; as its rings pass over it and collide with it, ice particles from within its rings collide with it and get vaporized, producing dusty rain which falls back onto them as dust storms. Over time, as more ring rain hits Saturn’s rings they thin out further until eventually disappear altogether.
As to when and how Saturn’s rings formed is still an unknown; most scientists assume they were created during the chaos of early solar system formation; however, a recent study suggests they may actually be much younger than initially anticipated.
Researchers published their findings in Science on September 15. Using measurements taken by NASA’s Cassini spacecraft shortly before its death dive, the team used math models to model Saturn’s rings using data taken in 2017. By calculating how much ring dust ended up falling onto Saturn from their calculations, the team predicted that all its rings will eventually drain away in less than 100 million years.
Scientists are thrilled to unveil an estimate for Saturn’s ring age that fits so closely with decades-old data from Voyager 1 and 2. Additionally, their “young-rings” model better explains some other mysteries regarding its rings; such as why Saturn seems tilted a bit. Scientists suspect the loss of Chrysalis may have compounded that tilt — an effect which is relatively common across giant planets.
The new research not only shows us that the rings are much younger than we thought, but it also offers insight into their formation in the future. Scientists propose that fragments from destroyed moons like Chrysalis could reenter their orbit and begin forming rings again, thus helping explain their uneven form and explanation for why certain regions appear darker or dustier than others.
The Ring Rain Phenomenon
Saturn’s rings are constantly bombarded by debris from other objects, while processes are also gradually eating away at their material. This eroding process is hastened by Saturn’s gravitational tug of war with its rings; but astronomers had never been able to accurately gauge how fast they are eroding until now with an analysis of data from Cassini mission and ground-based telescopes.
Prior to its fiery plunge into Saturn in 2017, Cassini completed 22 orbits that covered an interstellar gap between it and its rings, providing scientists with the unique opportunity to observe “ring rain.” Cassini’s Ion and Neutral Mass Spectrometer detected water ice and complex organic molecules falling from Saturn’s rings into its atmosphere at an estimated rate of 22,000 pounds per second – giving researchers insight into this rare natural event.
Droplets of icy rain appear to emanate from Saturn’s innermost edge where particle density is significantly lower compared with other parts of its rings system. Pulling these particles toward Saturn by its gravity, they then impact onto Earth releasing some icy droplets into our atmosphere – explaining its consistent nature.
Scientists had long anticipated that some ring material would eventually make its way into Earth’s atmosphere, yet their calculations did not anticipate its magnitude. By using readings from various missions including Voyager probes and Cassini, calibrated with measurements made by Hubble Space Telescope’s STIS instrument, Waite and his colleagues have created an accurate estimate for ring-to-atmosphere ratio.
Their findings were recently published in Science journal and will help astronomers gain a greater understanding of Saturn’s rings as well as how they relate to other processes within our Solar System. Their data may even lead to discovering exoplanets with similar rings reminiscent of those on Saturn! Furthermore, this research disproved some previous assumptions regarding their origin and structure; instead suggesting they formed very quickly in just several million years!
The Future of the Rings
Saturn’s rings are one of the most striking sights in our solar system, easily visible through even modest telescopes. Their primary component consists of chunks of water ice ranging in size from microscopic dust grains to boulders several yards (meters) wide. They orbit Saturn with great care, balancing between gravity pulling them towards it and other objects such as moons or micrometeoroids that pull away. Electrical charges from ultraviolet sunlight from the Sun or micrometeoroid bombardment can also cause particles to be electrically charged. Once they become charged, their balance of forces changes drastically, and they may be pulled in along magnetic field lines into Saturn’s upper atmosphere.
One theory on Saturn’s rings includes their formation by collisions between small, icy moons; this would disrupt their original shapes and give rise to their distinctive band structures. Another proposal suggests they originated as remnants of an enormous moon that got too close and was torn apart by Saturn’s gravitational pull; scientists conducting the new study believe this happened with Chrysalis, once measuring around as large as its third-largest moon Iapetus but now disintegrating due to being torn apart; Chrysalis’ loss may have played an integral part in creating many other unusual characteristics of Saturn such as tilt of 27 degrees!
As for the future of the show, its creators have already indicated there will be multiple seasons planned for it. They have stated they have five planned episodes ready and preproduction should start shortly.
As yet it remains uncertain as to which cast members from Season 1 will return for Season 2, however the showrunners have assured fans that each episode will explore new ground. They are also said to be working on a sequel that introduces Sauron and shows his takeover of Mordor.