On the Shores of Titan's Farthest Sea

by Michael Carroll

  “Beautiful?”

  She nodded enthusiastically. “Beautiful.”

  “So you see, it is just as I asserted earlier. A person can find beauty in the strangest of places.”

  Abby put the rose to her nose, sniffed, and closed her eyes. “Even in a storage closet on Titan.”

  Suddenly, looking back, it all became so clear. Looks like someone’s peace offering, Troy had said about the rose sitting on the table in her room. But he hadn’t meant he had put it there. It had been Piers. In fact, Piers had been there for her all along.

  “So it wasn’t Troy; it was you.”

  “Troy kind of got in the way. Inadvertently.”

  “He tends to do that a lot.”

  She leaned over and gave him a playful kiss, right on the lips. She realized it was something she’d been thinking about doing for some time.

  Piers leaned back in surprise, eyes wide. Then, a look of concentration and amusement on his face, he put his arms around her waist, pulled her to him and kissed her. Abby decided that this kiss was even better. It was a surprisingly good kiss.

  “Tanya and I were just discussing who we were going to miss when we leave this place. You’re on my list.”

  “And you, my dear, are on mine. You’re on several of my lists, in fact, from most brilliant meteorologist to favorite submarine skipper. Perhaps we should make sure this is not a final goodbye.”

  “Perhaps we should,” she agreed.

  (*)

  As Jeremy had business at the Bacab Colony, he would not be leaving with the last big Marine transport. That was fine with him; the commercial shuttles were far more comfortable. But he did need to make a decent farewell to the man who had seen him through this terrible, wonderful, frightening, exhilarating experience. At the hands of Master Sargent Dønnes, the assault of Northern Quadrant had been efficient and as close to peaceful as anyone could have hoped.

  He motored out by himself in the little inflatable, listening to the slosh of the methane, watching the scattered reflection of Saturn’s fuzzy orb, the distant cliffs, and the towering, abandoned drill. Upon his approach to the floating Marine ship, a ramp lowered to water line. Two Marines clambered down the ramp and helped Jeremy hoist the boat up, securing it to the slanted deck. At the top of the ramp, in the wide, neon-lit bay, stood a hulking silhouette that could be only one person, Master Sargent Dønnes,.

  The men shook hands and wished each other well. Jeremy declined the offer of entrance for a cup of coffee. He had already sampled the Marine version.

  “I can’t blame you,” Dønnes said cheerfully. They said their goodbyes.

  Motoring back to the beach, Jeremy was relieved to be done with his brief stint in military action. He cast a last glance over his shoulder as the gigantic craft lumbered into the air, leaving a drizzle of cryogenic liquid raining down into the sea. The blue ion engines flared and the craft turned, blimp-like, to begin its ascent back to Iapetus.

  He thought about the wonders he had seen. He had seen the vids, read about the ice mesas and the undulating methane lakes, but to be here was another thing entirely. Titan was a moody, beautiful place. He slowed the engine and let it drift for a few moments. The sound of the waves against the hull of the little boat soothed him. The place did remind him a little of Loch Ness, a place he had seen as a child. Even without long-necked sea serpents, Kraken Mare was a magical place.

  He beached the inflatable a dozen yards down shore from the closest habitat, just next to a mooring post. As he stepped out, he looked down. The wet sand had a strange pattern in it, a regular set of indentations. Most had softened into disks the size of a rover wheel, but several still held the imprint of something familiar, something webbed, reptilian. Did he see three claw marks spread out in a double v shape, and between them, a subtle webbing of scale pattern? An errant wave sloshed around the boat, around his feet, and over the sand. As it retreated, it took any beach imprint with it, away into the abyss of Kraken Mare.

  © Springer International Publishing Switzerland 2015

  Michael CarrollOn the Shores of Titan's Farthest SeaScience and Fiction10.1007/978-3-319-17759-5_60

  60. The Note

  Michael Carroll1

  (1)Littleton, CO, USA

  The package arrived in a hermetically sealed standard issue with a return post from somewhere on Mars. Piers popped it open. Inside was a real printed book, on wood-pulp paper, no less. The cover read, “A TRAVELER’S GUIDE TO TITAN by Abigail Marco.”

  Carefully, gently, Piers drew open the front cover. Scrawled across the inside page was a handwritten message:

  Dear Piers:

  My return to the warm canyonlands of Mars was a happy one, to say the least. I’ve settled into that small cottage I told you about on the rim of Kasei Valley. It was cheaper than I feared, and it’s just a ten-minute flight from Jeremy’s house. I had my first iced tea in two years, so I must be warming up.

  As you can see, I’ve followed your suggestion and pursued my dream of writing travel guides. My first, of course, is a compendium about Titan. It was an easy sell to the publisher because, as they said, it’s a book that has no competition yet.

  I’m serious about you coming to visit. It’s a long trip, but I do wish you’d come. I can show you the sites of Mars properly. Besides, if you really do miss me, that’s another thing we have in common.

  Love, Abby

  Piers flipped to the first chapter, past the front matter. The opening paragraph began:

  My advice to the tourist on Titan is the same as my advice to

  the European traveler in Central America:

  do not drink the water.

  He laughed, closed the book, and gazed out the window. The drill was immobile, but worker bees crawled over it from top to bottom, retrofitting all kinds of devices onto it to seal the waters of Titan’s deep ocean where they belonged, once things got started again. It was a relatively clear day. Saturn sliced a thin, blurry crescent through the wine-red sky. He glanced around at his office. He had kept it much cleaner since Abby had left. He missed her. Things just weren’t the same.

  As he opened the book again, he thought about the price of a ticket to Mars. His eyes settled on the book’s dedication. It read:

  “To Piers Wellington, who finds beauty in the strangest of places.”

  -end-

  Part II

  The Science Behind the Fiction

  © Springer International Publishing Switzerland 2015

  Michael CarrollOn the Shores of Titan's Farthest SeaScience and Fiction10.1007/978-3-319-17759-5_61

  61. The Science Behind the Fiction

  Michael Carroll1

  (1)Littleton, CO, USA

  Vesta and Asteroid Mining

  The character of Horf comes from the asteroid 4 Vesta. Vesta is the second most massive asteroid in the Solar System. Although Pallas is larger, Vesta is more dense, making up some 9 % of the entire mass of the main Asteroid Belt. It is second only to the largest of the asteroids, Ceres (Fig. 61.1).

  Fig. 61.1Titan, ca. a. d. 2260 (Base map NASA/JPL-Caltech/Space Science Institute)

  Much of what we know about this huge asteroid comes from the Dawn spacecraft, which orbited the cosmic rock for 14 months, surveying its minerals and mapping its gravity in detail.1 Combined with analysis of meteorites that have come from Vesta, scientists have assembled a picture of an asteroid rich in resources, a world with a past somewhere between a dead moon and a geologically active planet. Vesta is a world of basalts (rocks of volcanic origin). Minerals confirmed or strongly implicated so far include olivine, pyroxene, pigeonite, plagioclase and orthopyroxene. Like a planet, Vesta appears to be differentiated, meaning that the heavier elements settled to form a core when the asteroid was still molten. A differentiated asteroid should have far more complex geology and mineralogy than a simple one, like the smallest moons of Saturn, which seem to be fairly homogeneous in composition. Vesta’s rocky composition and volcanic history may well make it a targ
et for future mining operations (Fig. 61.2).

  Fig. 61.2NASA/JPL’s Dawn spacecraft revealed an asteroid rich in geology. Dawn took this image of asteroid 4 Vesta on July 24, 2011, showing its towering mountain at the south pole, seen here at lower right. Grooves encircle the asteroid along the equatorial region. Dawn’s framing camera was built by the Max Planck Institute (Courtesy NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

  Vesta’s surface is surprisingly clean, as asteroids and moons go. On Earth’s Moon and many other natural satellites and small bodies such as asteroids and comets, the space environment “weathers” surfaces, causing them to accumulate metallic particles of iron. This dulls and subdues the naturally fluffy surface texture. But very few of these particles blanket Vesta’s landscape, leaving it unusually reflective. Fresh impacts and landslides on steep slopes continually mix the surface layer.

  Vesta’s equatorial region is belted by a series of remarkable grooves. These deep channels may be graben, which are faults caused by the expansion of Vesta’s surface. They may have been triggered by the massive impact that dug out the crater at the south pole. The Rheasilvia impact crater has a colossal central peak that towers three times as high as Mt. Everest. The grooves may also have been the result of Vesta’s differentiation, forming as the cooling crust pulled apart above sinking metals on their way to the molten core. The shape of the valleys indicates forces from within, rather than near-surface movements.

  A wide range of different terrains underscore Vesta’s planet-like nature. The giant asteroid has a global dichotomy—one hemisphere is different than the other.2 Craters dominate its more ancient northern hemisphere, while the brighter south is smoother and grooved. Vesta shows a variety of color as well. Southern lands match basaltic formations, while northern craters have stirred up a host of minerals from within. The equator is peppered with hydrated minerals such as hydroxyl, meaning that water is chemically trapped within the rocks. These minerals may have come from the constant rain of carbon-rich meteors in the Asteroid Belt. Several sites show vent-like pits where volatiles such as water may have boiled out from the asteroid’s interior.

  Asteroid mining has been the subject of many futurist writings, and with good reason. Telescopic observation and spacecraft encounters, as well as the study of meteorites, tells researchers that the asteroids may contain a wealth of metal ores, minerals and volatiles such as water and methane that can be used for fuel or human-supported activity. Some estimates3 suggest that mineral value in the main Asteroid Belt may reach $100 billion (in today’s market) for each person living on Earth. A roughly spherical asteroid with a 1-km diameter has the mass of 2 billion tons. Within this bulk, there may be upwards of 30 million tons of nickel, 1.5 million tons of cobalt and 7,500 tons of platinum. Much of this material may be more accessible to the surface than comparable metals on Earth, where mines are becoming deeper or more extensive, causing more and more damage to our environment.

  Most asteroids inhabit the main belt, a torus of debris circling the Sun between the orbits of Mars and Jupiter. The asteroids fall into three general categories. C-type stony asteroids, or carbonaceous objects, make up more than three quarters of the known members. Their composition is similar to that of the early solar nebula, but without the volatiles such as hydrogen or helium.

  M-type asteroids are metallic, and are the most rare. They are rich in nickel and iron.

  S-type asteroids are a mix of stony and metallic material, and make up roughly 17 %. These are rich in nickel, iron and magnesium. Vesta is similar to an S-type asteroid, although it has been given a class of its own, shared by a small number of other asteroids.

  Early asteroid mining will probably resemble conventional terrestrial mining. Solar power will be common, as the Sun is near enough to the main belt to provide plenty of power. Automated operations will be carried out wherever possible, because working in a vacuum is hazardous, and working in mining environments is one of the more deadly careers on the books. Strip mining of surface materials would be combined with tunneling into veins of subsurface minerals. Both techniques will require new technologies, but mining of the surface will be especially challenging, as the mined talus will tend to float or fly off the surface. Tents or canopies may be used to harness the mined products. Some asteroids are likely dead comets, containing volatiles surrounding the precious ores. In these cases, heat can be used to melt and vaporize the matrix to free the materials. Some stony/metallic asteroids may have precious metals mixed with debris on the surface, where magnetic rakes or scoops could be used to gather resources.

  Asteroid mines may have refineries on site, or they may send their metal treasures to other locations. Once material is ready to ship, rocket fuel can be distilled from the asteroid’s volatiles, such as hydrogen, oxygen and methane.

  Our Vesta miners in Farthest Sea added another technique to their toolbox: biomining. As the Vesta guide told his pretend honeymooners, “Acidithiobacillus and Leptospirillim are the miners. They use the sulfur in the acid to break down the rocky material. What’s left is the really good stuff.”

  In today’s global economy, what was once considered mining waste is now recoverable resource, thanks to the use of microbes. One area in which microbe mining has seen great success is in the copper mines of Chile. Chile is home to Codelco, the largest copper mining company in the world. Codelco mines and other mining facilities use Acidithiobacillus ferrooxidans and Thiobacillus ferrooxidans bacteria to break down minerals, improving copper recovery rates and reducing operating costs. Microorganisms naturally liberate copper from rocks, but the process tends to be gradual, taking centuries or millennia. To speed up the process, scientists use a technique called bioleaching. Placing ores into acid, they add bacteria that change the solution so that it dismantles the rock and frees the copper in liquid form. The copper is sent through an electrochemical process, where it turns back into solid metal.

  Over 30 strains of bacteria are being used for biomining, and this figure is growing steadily. Biomining now accounts for roughly 15 % of all copper mining worldwide, along with 3 % of all gold mining. It also contributes substantially to nickel, cobalt and zinc mining. Biomining plays a key role in the copper mines of Uganda, the gold mines of Ghana, South Africa, central Asia, and Australia, and in various mining operations in Finland.

  As for near-future asteroid mining prospects, a class of “easily retrievable objects” (EROs) was identified in 2013 for near-Earth mining. Over 9,000 asteroids were studied, and the list was culled to a dozen rocks ranging in size from 2 to 20 m in diameter. All of these could be brought into a near-Earth orbit using a velocity change of less than 500 ms−1 (1,100 mph/1,800 kmph). Several private companies are already interested in the possibilities of mineral exploration on these cosmic boulders.

  Also under study by NASA is the possible human exploration of a near-Earth asteroid. The Asteroid Redirect Mission would bring an asteroid into a stable lunar orbit, where a crew could venture out to study it. Designers are studying two concepts for capturing the asteroid. One would capture a small boulder using an inflatable bag. A second design envisions a spacecraft using a robotic arm to snag a large boulder from the surface of an even larger asteroid.

  The Lay of the Land on Titan

  Titan is unique among moons in our Solar System, as the only moon to have more than just a trace atmosphere. Its opaque nitrogen-methane cocoon is the second thickest among all the solid bodies of the Solar System. At 1.5-bar, Titan has more air pressure than Earth does. Its atmospheric blanket sustains a surface temperature of −178 °C/−290 °F, much warmer than nearby Enceladus, whose daytime temperatures hover around −201 °C/−330 °F. Titan’s day drags on for 382 h, about equivalent to 16 Earth days. Its year—identical to Saturn’s—lasts a lingering 29.7 Earth years. Titan’s environment is nearly as complex as Earth’s, with dynamic meteorology and an active hydrological cycle unlike anything found throughout the Solar System, with the sole exception of our own world. Titan’s landsc
apes echo those of our terrestrial vistas. Dendritic channels, the result of liquid erosion, score its face and carve valleys. Dark hydrocarbons, washed from the highlands, pool in low-lying areas. Aeolian [wind-driven] effects leave trails of scattered dust and sculpted forms, piling up sand into great fields of dunes. We see cloud systems and storm fronts. In short, Titan generates Earthlike processes, but they are occurring in alien materials. The surface of Titan has rocks, but the rocks are thought to be water-ice. You have water available, but it’s frozen ‘rock solid.’ And the rains of Titan are cryogenic methane, similar to the natural gas with which many of us heat our homes. As we learned from poor Kevin Nordsmitt, “If he didn’t know better, he could convince himself that the place was made of stone. But the ground and mountains and boulders of Titan were water-ice, frozen to the consistency of granite.”

  Titan’s murky blanket of nitrogen and methane has its own story to tell. On both Earth and Titan, weather is nature’s attempt to balance out temperature and pressure. Heat comes in from the Sun, and wind carries the warm air to colder areas. Just 93 million miles from our own world, the Sun pumps prodigious amounts of energy into Earth’s system constantly. This makes our atmosphere a vigorous and active place. Our changeable meteorology stands in stark contrast to that of distant, frigid Titan. Titan receives one-hundredth the amount of sunlight that Earth does. Less heat enters the atmosphere, resulting in more gentle mixing of the air, which means that there are fewer individual weather events. An occasional storm may be all that occurs over the course of many years. Scientists liken this atmospheric heating to a pot of water on a stove. When the flame is first lit, an occasional blob of water will rise from the bottom of the pan to the top, making a little turbulence. As time goes on and the water gets hotter, more and more of those blobs will rise through the liquid. The water in the pot can be very turbulent even before the water itself begins to boil. Titan's atmosphere may be similar to the beginning stages of our warming pot, where blobs of warm fluid come up only rarely. Earth's atmosphere is similar to the pot's liquid at the boiling stage.