Scientists Dodge Youthfulness of Saturn Moon Enceladus
Planetary scientists have figured out that the geysers of Enceladus vary during its orbit, but seem oddly silent about the question of how long the little moon could remain so active.
Cassini scientists have observed the brightness of the Enceladus geysers for several years now, from various angles. It appears, according to a new paper in Nature, that the geysers are brightest when the moon is farthest from Saturn. They suspect that the southern-hemisphere cracks or “tiger stripes” are under tension at that point, opening them up for greater escape of salty water. When Enceladus is closer to Saturn, the cracks are under compression and close up a bit more, like a constricting hose nozzle. This is explained in another Nature article by John Spencer, who also suggested that the findings hint “at a subsurface source of liquid water and a probable subsurface ocean.”
Whether Enceladus has an ocean remains debatable, however. A recent paper in Icarus found that the only way to sustain a liquid ocean under the crust was to assume that the ice is not as elastic as previously assumed—and then, only under specific conditions:
Though anelastic behavior increases the heating rate, it is insufficient to maintain a global subsurface ocean if the ice layer is convecting, even though a wide parameter range is taken into account. One possibility to maintain a global ocean is that Enceladus’ ice shell is conductive and its tidal response is similar to that of the Burgers body with comparatively small transient shear modulus and viscosity. If the surface ice with large viscosity is dissipative by anelastic response, the heat produced in the ice layer would supersede the cooling rate and a subsurface ocean could be maintained without freezing.
Water = life?
The popular press reported the findings about the orbital variability of the geysers, but said nothing about the sustainability of this level of activity for billions of years. Instead, they latched onto the suggestion that Enceladus might have a liquid ocean, implying it might have life. A BBC News article, for instance, focused attention on Spencer’s brief suggestion about this:
“The likely presence of liquid water and complex organic chemistry makes Enceladus especially intriguing as a potential habitat for extraterrestrial life, providing additional motivation for investigating its interior.”
“Liquid water was key to the development of life on Earth, so these discoveries whet the appetite to know whether life exists everywhere water is present.”
None of the papers or articles, however, addressed the more perplexing question of how Enceladus could maintain this level of activity for billions of years. Ever since the geysers were detected in 2005, it has been a major mystery to account for the sustainability of such activity for long ages (search “Enceladus” in these pages, e.g., 4/06/13, “Bimbo Eruptions in the Solar System”).
Et tu, Dione?
An earlier article on Science Daily reported that Saturn’s larger moon Dione might also have activity–also ignoring the age question, but leaping onto the life suggestion:
Other bodies in the solar system thought to have a subsurface ocean — including Saturn’s moons Enceladus and Titan and Jupiter’s moon Europa — are among the most geologically active worlds in our solar system. They have been intriguing targets for geologists and scientists looking for the building blocks of life elsewhere in the solar system. The presence of a subsurface ocean at Dione would boost the astrobiological potential of this once-boring iceball.
The Nature paper about Enceladus said nothing about life, oceans, or habitability – but it ignored the age question, too.
Talk of biology and “building blocks of life” at the mere hint of water is a classic red herring, a distraction or sidestep around the major conundrum facing planetary scientists: how to keep Enceladus going for billions of years. It’s not a problem for Biblical creationists who expect Enceladus, Io and the other active bodies in the solar system to be thousands of years old but it’s a major problem for secularists who count ages in billions. We need a new word to describe this tactic of quickly focusing on life whenever water is suspected on another world. How about “hydrobioscopy“? We’ll add that to our Darwin Dictionary.
There’s no way evolutionists and other secular scientists could face up to this hard evidence if it might give aid and comfort to their sworn enemies, so they change the subject rapidly, thinking that talk of the possibility of life on a frozen, airless world might be more sexy than hand-wringing in public over the falsification of their long-age beliefs. For comfort, they run to gulp down more Darwine. We need to hold their feet to the fire, not their mouths to the firewater.