Cassini keeps revealing puzzling phenomena in the Saturn system that challenge traditional theories and date estimates.
Let’s scour the Saturn system for news, working from the planet outward.
Saturn, the 2-billion year age gap: PhysOrg says that Sandia Labs has a machine that “helps solve Saturn’s 2-billion-year age gap.” Did you know there was a 2-billion year age gap? Sure enough, “Planets tend to cool as they get older, but Saturn is hotter than astrophysicists say it should be without some additional energy source.” Scientists at the national lab used models and experiments to test whether the missing energy source could be “helium rain” which is not needed at Jupiter, but bridges the gap at Saturn.
Saturn rings: A guy at U of Leicester claims that the distribution of ring particles is in steady state, but the article on Science Daily doesn’t say how long that state could last. He does invoke an ad hoc story: “With a high probability these particles are remains of some catastrophic event in a far past, and it is not surprising that there exists debris of all sizes, varying from very small to very large ones.” His name is Professor Brilliantov.
Enceladus heat: Another paper on Icarus deals with the heat flow problem on Enceladus, the little Arizona-width moon that sends out 5 gigwatts of heat through its south-pole geysers. They don’t try to solve the problem of keeping this little moon active for 4.5 billion years. Instead, they tackle a more modest problem of how the funiscular plains (ropy-looking terrain) between the “tiger stripes” were created. “A folding origin requires extreme heat flow, conductivity, and surface temperature,” they say, suspending credulity a bit. “While extreme, these conditions can be met within the south polar terrain.” Sounds like they added to the heat problem on this little moon.
Tethys mystery: Some bizarre red-colored arcs have been found on Tethys, the next moon out from Enceladus. Scientists have no idea what formed them, Space.com reports. They “can’t be explained,” the headline says; “nobody knows how they got there.” They were visible in 2004 images, but really popped out in April this year thanks to a better viewing angle. “The origin of the features and their reddish color is a mystery to Cassini scientists,” Astrobiology Magazine says. Are they fractures seen at an unusual angle? Are they evidence of outgassing? “It’s surprising how extensive these features are.” Paul Helfenstein draws one conclusion: “The red arcs must be geologically young because they cut across older features like impact craters, but we don’t know their age in years.”
Dione gets one final close look on August 17, Space.com reports. “There are intriguing hints that perhaps there’s something similar going on on Dione that we might have on Enceladus, but we haven’t found the equivalent of a smoking gun,” the project scientist says. In October and December, there will be three final flybys of Enceladus, including a plunge into the vapor of a known plume.
Titan tubs: Some depressions in Titan’s north polar lake regions appear to be “bathtub rings” from lakes that dried up, Astrobiology Magazine reports. Scientists are inferring that Titan’s seas are dynamic features, waxing and waning according to conditions in Titan’s 30-year orbit, although one critic considers this “speculative.” There are about 28 of these depressions that have been compared to Death Valley’s Badwater basin—a puddle that expands and contracts according to the weather. The article briefly mentions the problem that Titan should be covered in liquid, but with a reversed conclusion:
Changes in Titan’s atmosphere could also play a role, MacKenzie said. Ultraviolet rays in the upper part of the moon’s atmosphere continually destroys methane. If no source replenishes it, Titan could be in what MacKenzie called a “drying out state,” and liquid from the surface—such as that at the equator—could have been permanently lost to the moon.
Actually, the UV light converts methane to ions that should recombine into ethane, a liquid at Titan temperatures. It should rain down and collect on the surface into lakes and seas. Before Cassini, many thought a global ocean of liquid methane and ethane existed up to a kilometer in thickness, based on 4.5 billion years of this irreversible process. Titan’s dryness was one of the great surprises of the mission.
Iapetus ridge: One of the most bizarre features Cassini discovered was a mountain range on Iapetus that girds its equator. The mountains are tall (up to 12 miles high) and thin. “What’s this ridge on Iapetus?” PhysOrg asked in June from an article by Fraser Cain at Universe Today. “What could possibly create a feature like this?” —as if the moon’s dark-light dichotomy isn’t weird enough (12/14/09). Cain tours a few other mysteries at Saturn (the planet’s north pole hexagon, the Enceladus geysers, etc.), then looks for answers to the Iapetus mountains. Possibilities: (1) the moon’s innards squeezed out of cracks created by tidal forces; (2) Iapetus wandered close to Saturn and consumed some of its rings; (3) an asteroid impact smashed Iapetus to pieces; when it collected itself, material squeezed out the equator. Each has problems. Interestingly, two small moons—Atlas and Pan—have equatorial ridges thought to be ring material, but Iapetus is too far away to make that explanation plausible. A paper on Icarus examines another possibility: rapid despinning of the moon from (you guessed it) an asteroid impact—the fix-it tool for every solar system problem (9/23/13). “We show that Iapetus’ shape can be explained by an abrupt change of rotation due to a giant impact,” seven French and Czech scientists claim. “Formation of the equatorial ridge was facilitated by non-linear stress-dependent rheology of ice.” Take your pick.
Saturn is a treasure trove of exciting features that challenge the A.S.S. Thank you, Cassini, for exposing the moyboys to evidence that doesn’t fit their dogma. Critics of a young solar system often retort, “Yeah, but these things don’t fit 6,000 years either.” They miss the point. Nobody can date these things accurately, and critics of the A.S.S. don’t claim to from the Cassini evidence. What can be done, however, is to infer reasonable upper limits to the ages of the rings, the geysers, Titan’s atmosphere and the other anomalies. Those upper limits (even if 100 million years) are far, far too short for Darwinian evolution—thus the secular gymnastics to try to keep them old (10/07/10).
We use this to point out that the A.S.S. is a straitjacket. Critics of a young solar system say that youthful estimates in thousands of years are a straitjacket; i.e., that it’s impossible to fit these phenomena into such a short time. That argument cuts both ways. When you see young phenomena, like the geysers, that cannot be kept active for anywhere near billions of years (but you need to cover your A.S.S.), you are forced into inventing implausible just-so stories to maintain your belief (ex. 10/07/10). We claim that it’s more reasonable to set upper limits than lower limits because the observation-to-assumption ratio is lower. The lower the ratio, the better the science (see Extrapolation in the Baloney Detector).