It’s Official: Saturn’s Rings Are Young
There’s no stretching the truth any more. Cassini data have led all the ringmasters to the conclusion that the rings of Saturn are not billions of years old.
For over 15 years, Creation-Evolution Headlines has reported the tug-of-war between planetary scientists on the age of Saturn’s rings (e.g., 2/12/02). Indications that the rings are much younger than Saturn’s assumed age (4.5 billion years) go back to the Voyager missions. Several lines of evidence pointed to youth, but planetary scientists tugged back at the evidence, inventing ways to keep the rings billions of years old. Now, they have given up. Reality won the match: the rings are young!
Paul Voosen reports in Science Magazine, “Saturn’s rings are solar system newcomers.”
The rings of Saturn seem like permanent fixtures in the solar system, firing the imaginations of poets and scientists alike. But observations made this year by NASA’s Cassini spacecraft in the final months of its existence, and reported here last week at a meeting of the American Geophysical Union (AGU), show they are surprisingly youthful: Until a few hundred million years ago, they did not exist. Saturn acquired its jewels relatively late in life. If any astronomers had gazed at the sky in the time of the dinosaurs, they might have seen a bare and boring Saturn.
Of course, to moyboy scientists, ‘young’ is a relative term. The new estimate of 200 million years max doesn’t sound young to most people. It is, however, only about 5% of the assumed age of the solar system. That conclusion leaves secular planetary scientists in a quandary: it will now require ad hoc special conditions to explain the rings in a separate theory, apart from the general theory of the solar system’s formation. Not only that, it will require a relatively recent event that makes humans look special, because we live in a rare epoch when the rings exist to be observed and enjoyed by sentient beings.
The brightness of the rings was a primary evidence for youth, because rings should get dirty over time from meteorite bombardment. Added to that, the B-ring—thickest of all—turns out to be less dense than thought. The clincher came from the Cosmic Dust Analyzer (CDA), which measured far more dust than expected:
After 12 years of painstaking measurements and analysis, the Cosmic Dust Analyzer, a Cassini experiment that measures small particles, has found that the micrometeorite flux is large—“inconsistent with an old ring,” says Sascha Kempf, a space physicist at the University of Colorado (CU) in Boulder who led the work. Dust from the outer solar system moves more slowly than expected, which allows Saturn’s gravity to pull more of it in. The flux, about 10 times higher than estimates from before the Cassini mission, suggests a ring age of between 150 million and 300 million years, or even younger. “Our measurement is the most direct way you can measure it,” Kempf adds. “There’s not much you can do about it. It has to be young.”
How are the scientists dealing with this quandary? Basically, Voosen writes, they are appealing to the Stuff Happens Law (i.e., chance). Leading ringmasters Larry Esposito and Jeff Cuzzi have been worrying about this for decades. Eleven years ago, Esposito proposed a thick B-ring to keep at least that part going for a billion years (2/04/16). Now look what they say:
In the early 1980s, Esposito says, the two Voyager spacecraft flew past Saturn and returned data that seemed to point toward a low ring mass—and a possible youthful age. But Voyager scientists had a hard time coming up with a compelling scenario to explain it—the notion that a saturnian moon might have shattered at a time when the solar system would have had few potential asteroids or comets to ram into it seemed far-fetched. “The best idea we had then was that we’re just lucky,” Esposito says. “I’m back to square one.”
Scientists have only begun to study how the ring-forming collision could have happened. “Part of the reluctance for everyone to leap off this bridge into the unknown is we haven’t had any kind of feasible explanation,” Cuzzi says. It’s time for new ideas, he adds. “The solar system could be full of surprises like this.”
Cuzzi’s last statement could be taken as a covering model for future upsets. Or, it could be taken as an indication that planetary scientists don’t understand the solar system as much TV specials make it seem.
The situation is analogous to the fossil record for Darwinism. Theory predicts gradual change and clear lines of descent, but the evidence keeps showing abrupt appearance, living fossils and ‘convergent evolution’ (hear Casey Luskin talk about this on ID the Future). As I see it, the evidence is baffling for Darwinians because Darwinism is false. Similarly, the youthful rings of Saturn are baffling to secular planetary scientists because the solar system is young.
I had occasion to meet these scientists when I was at JPL, and I spoke with them on rare occasions. I was responsible for their computers at their universities, and saw them often in periodic Project Science Group meetings at the lab. They were each amicable and pleasant in person. I listened to their presentations with great interest, wondering which view would prevail. It was clear to me that nothing would dislodge their belief in billions of years, but there was a subtext that it would be very troubling to them if the rings turned out to be young. These quotes show that to be the case: they are flummoxed and dumbfounded by the evidence. They have no explanation, and they admit it.
I’ve been intrigued by this mystery ever since I read about it in Astronomy Magazine and Sky & Telescope back in the 1980’s, so it was good to actually meet the experts in person. In my non-JPL science presentations, I’ve long used Saturn’s rings as one of many examples that the solar system is young. While maintaining my humility as not in their league regarding math and physics, I do find some gratification, at least in this instance, at being found right in the end.