by Roger Bourke White XIV, Prof. Em. Planetology, University of Titan Colony
The first explorers of gas giants, using robot probes made possible by HX technology, found as expected that their atmospheres first thickened and then solidified as the probes descended. But because the fluid-solid transition is caused by a change in pressure, not a change in chemical composition, these planet “surfaces” are very different from those of rocky planets like those in the Inner System. On Earth, for example, the gaseous layer is primarily nitrogen and secondarily oxygen, the liquid layer is almost entirely water, and the solid layer is primarily silicates. In the gas giants all layers are hydrogen and helium, with methane, water, and ammonia as the major impurities.
Those explorers also found that, just as predicted by a certain fiction writer in the early 21st century, immediately above the fully solid Bedrock Zone of each giant is a semi-solid Ooze Zone. The atmosphere there is thixotropic, meaning that the mix acts solid when at rest, but the more it is sheared—forced to move around—the more fluid it becomes. It is like sticky mud on a path or modeling clay in your hands: The more you push it around, the softer it gets.
What moves the Ooze Zone around, as well as the more fluid layers above it, are turbulence, caused by motion in and among all the fluid layers; convection currents, caused by temperature differences; and Coriolis effects, caused by the planet’s rotation. All those same forces try to move the solid parts—as indeed they do on rocky planets—but the solid parts mostly do not move. The boundary lines between the Atmosphere Zone, the Ooze Zone, and the Bedrock Zone are not sharp. Interaction with the lower Ooze Zone does bring vigorous cracks and limited motion to the upper layer of the Bedrock, but though routine this is infrequent, and the cracks quickly heal back to solid state. Also, although the blocks in the Bedrock Zone are strong enough to resist the horizontal Coriolis effect, they can be driven up and down by even slower-moving convection currents comparable to those generating Earth’s plate tectonics.
In the Ooze Zone itself, the full fluid, the oozy mud, and the solid boulders are the same material, and the atmosphere changes among the three states easily and constantly, with the upper part mostly mud-like and the lower part mostly boulder-like.
Similar transitions occur in all the fluid layers. Although the motion above the Ooze Zone is on average much faster, nevertheless small volumes occasionally are quiet long enough to harden into lumps, so that the atmosphere is like air with snow or hail in it. The Ooze Zone is somewhat arbitrarily defined as the layer at which lumps are routinely in contact with other lumps, and the wind slows down considerably from the friction that comes from blowing around the solid chunks.
The top of the layer acts like a perpetual fall day with leaves endlessly shuffling in the breeze. Except that crushing a “leaf” would not produce fragments or dust but would vaporize it, so that it vanished back into air, and cupping your hands to still the air’s motion would let it solidify into a leaf.
As you move down through the Ooze Zone the leaves become larger, more solid, and more closely spaced until at the bottom continent-sized plates grind against each other as Coriolis forces spin them around horizontally. Country- and county-sized boulders act like crude ball bearings, with the mud between as lubricating oil. Warmed by the friction, the mud and boulders try to rise between the huge blocks pulled downward by gravity, grinding their lower surfaces into more bearings and oil, while the blocks’ upper surfaces grow from any stilled fluid lying next to them.
This grinding and churning of the Ooze Zone has been going on for billions of years, since the gas giant planets were formed. While primarily a mixing process, it is also a melting and refreezing process, which means it is also a distilling process—the melting and refreezing tends to separate out the ooze’s constituent minerals into distinct groups, creating veins in the boulders. The further up in the layer, the more this tendency is counteracted by the grinding and convection, but veins created in the lower part of the zone will survive for long periods when they become part of a solid quiet area.
Most veins created by millions of freeze-melt cycles are worthless. Some have interesting properties in their native high-pressure environment, but are not stable when retrieved. However, a handful of these veins contain materials that remain valuable at human-compatible temperatures and pressures. The first and the only compound of commercial interest so far is Rubyzin.
Rubyzin is iridescent. It has been called “the Platonic ideal toward which mother-of-pearl strives”.
During the early atmospheric explorations of Jupiter, the first crystals of Rubyzin brought out and shown off by Belter scientists were fist-size. Twenty years after those first crystals were brought back, Jourdain M’ba Ondimba of Mars discovered that a finely powdered preparation of Rubyzin applied to human skin was absorbed by the hair follicles, and for a while as the hair grew out it became (Dr. Ondimba insisted on the term as both evocative and accurate) sparkly. A beard would be sparkly for perhaps a week, head hair for a month or so, and sparser arm or leg hair for a year, more or less. Thus applied, Rubyzin also had a mild euphoric effect, lasting for several hours, so that a person wearing Rubyzin looked good to others and felt good about themselves, usually making them more pleasant to be around.
Once this was discovered, more Rubyzin immediately began to be mined from Jupiter, and soon Rubyzin-based skin creams and cosmetics were used throughout the Solar System.
A quirky sociological study by my esteemed colleague R. B. W. Vijayasarathy demonstrates that the spread of Rubyzin use through the Solar System was far faster as measured in persons per year than that of tobacco through Eurasia, from its first 1494 use in Spain to its 1598 introduction to Korea by invading Japanese armies. Fortunately, other studies show that, unlike tobacco, Rubyzin has no deleterious effects on health. Its euphoric effect approximates that of a moderately satisfactory sexual encounter or of a good night’s sleep, an excellent breakfast, and an invigorating walk to work, and is less than that of the two scenarios combined. Therefore, no System government currently restricts or regulates Rubyzin.