Cassini Grand Verdict: Saturn Rings Younger Than Expected

With the orbiter’s best-yet images and data now coming down, a long-running debate about the age of Saturn’s rings is concluding in favor of youth.

Planetary science moyboys have strongly desired to keep Saturn’s rings old, because it would eliminate two problems of a philosophical nature: (1) avoiding the necessity of invoking some ad hoc event for their origin long after Saturn formed, and (2) explaining why we can see them in the recent (400-year) telescope age—a “special time” in the history of the solar system. Those desires are fading fast, now that Cassini, completing its final high-dive orbits, is sending back unprecedented high-quality measurements of ring mass. Jonathan Amos reports from the BBC News:

Cassini is essentially trying to weigh the rings. Their mass says something about their age.

The more massive they are, the older they are likely to be. Some scientists think they could even have formed with Saturn itself 4.6 billion years ago. They would certainly need a large mass to withstand the forces that might erode them over time, such as collisions from tiny meteoroids. But it is looking like the opposite may actually be true – that their mass is less than previously estimated.

If confirmed it points to the rings being the remnants of some object that has broken apart around Saturn in the recent past.

Cassini dives through the gap between the D Ring and Saturn during its Grand Finale before burning up in Saturn’s atmosphere on September 15, 2017.

Further measurements over the next few orbits should confirm these initial estimates of youth. The team is tossing around thoughts of rings 100 million years old, which sounds very old indeed, until one realizes that is only 1/45th the assumed age of Saturn. What was going on those other 44/45ths before rings appeared out of nowhere, somehow, by chance? Philosophically speaking, multiplying ad hoc events would not only violate Ockham’s Razor that favors simplicity, but would still run counter to other known forces that destroy rings.

“So, we’re heading in the direction of the rings being perhaps 100 million years old or so, which is quite young compared to the age of the Solar System”

Project Scientist Linda Spilker sounds like the Cassini team is being forced into these inconvenient sequels, as she ramps up the perhapsimaybecouldness index only to come back to the realities of physics:

“For younger rings, it would require a comet, or a centaur (one of a group of small, icy objects), or perhaps even a moon moving too close to Saturn. Saturn’s gravity would break apart that object and then the remaining bits would go on to form rings,” explained Linda Spilker, Nasa’s Cassini project scientist.

“Perhaps that’s happened more than once. Maybe some of the differences we see in the rings are from different objects that were broken apart. But if the rings are less massive they won’t have had the mass to survive the micro-meteoroid bombardment that we estimate to have happened since the formation of the planet.

“So, we’re heading in the direction of the rings being perhaps 100 million years old or so, which is quite young compared to the age of the Solar System,” she told BBC News.

Micro-meteoroid bombardment is not the only destroyer of rings. Spilker did not mention sunlight pressure (the Poynting-Robertson Effect), collisional spreading, sputtering (erosion on the atomic scale), and gas drag (Saturn’s atmosphere pulling on the rings). Such forces are commonly discussed in the secular scientific journals.

Remember that “100 million years” is an upper limit; the rings could be much, much younger. Notice that she said “perhaps” 100 million years old “or so” leaving lots of wiggle room. That’s like seeing Egypt’s pyramids for the first time without historical clues, and claiming that they are “perhaps 100 million years old or so.” Any number from 3,000 years up would fit that waffly description. But then the claimant would have to deal with known pyramid-eroding forces like wind, rain, and weathering. These would force the estimates downward closer to reality.

Suppose creationists make a bargain with the scientific old-age materialists. We’ll expand the age of the solar system by three orders of magnitude (10 million years) if evolutionists will reduce their estimate by three orders of magnitude (4.5 million years). Deal? Won’t ever happen. Why? Darwin needs the billions! His disciples could never squeeze the Cambrian explosion, dinosaurs, and Neanderthals into such a short time. If you think that those are matters of biological evolution, realize that what happens in Las Vegas doesn’t stay in Las Vegas. Darwin’s Lady Luck theory needs billions more to form the sun, Saturn and everything else in space before Lady Luck invents biology.

Time is the hero of Darwin’s plot, and without it, the whole Grand Scenario of scientific materialism falls apart.

Retro poster created for Cassini Grand Finale (JPL)