Moon.”
Grant couldn’t blame her, especially if she had a position on a tenure track at Lunar U.
“And who was your other assistant?” he asked.
“Not an assistant, my friend. He was Dr. Wo himself.”
“He’s a fluid dynamicist?”
“He was, before he was elevated to the directorship. Even so, we worked together quite a lot—until …” Muzorawa hesitated.
“The accident,” Grant finished for him.
“You know about that.”
“A little.”
“A little knowledge can be a dangerous thing,” Muzorawa misquoted.
“Then I ought to get more knowledge,” said Grant.
Muzorawa didn’t argue the point. Neither did he add to Grant’s knowledge of the accident.
The fluid dynamics problem he faced, Grant quickly learned, was that they were trying to study conditions that had never been experienced before. With meager data, at that. Hundred of automated probes had been sent into the unmeasured deeps of the Jovian ocean, but the data they returned were nothing more than a series of pinpricks in a sea of ignorance ten times wider than the whole Earth.
Squeezed relentlessly by Jupiter’s massive gravity, the thick, turbulent Jovian atmosphere is compressed into liquid some seventy thousand kilometers below the visible cloud tops: a strange and unknown ocean, water heavily laced with ammonia and sulfur compounds. Yet the ocean’s temperature is far below the Earth-normal freezing point; under Jupiter’s merciless pressure, the water liquefies despite its frigid temperature. With increasing depth, though, the sea becomes increasingly warmer, heated by the energy flow from the planet’s seething interior.
That ocean is at least five thousand kilometers deep, Grant saw. More than five hundred times deeper than the deepest trench in any ocean on Earth.
And that was barely scratching the surface of gigantic Jupiter. For the first time, Grant began to understand how truly immense the planet was. The numbers didn’t even begin to tell the story; they couldn’t. Jupiter was just too mind-numbingly
An ocean more than ten times wider than Earth and five hundred times deeper, yet it is nothing more than a thin onion-skin layer on the planet’s titanic bulk. Below that ocean lies another sea, an immense brain-boggling sea of liquefied molecular hydrogen almost sixty thousand kilometers deep. Nearly eight times deeper than the whole Earth’s diameter!
And below
At the planet’s very heart lies a solid rocky core, at least five times larger than Earth, seething with the appalling heat generated by the inexorable contraction of the stupendous mass of material pressing down to its center. For more than four billion years Jupiter’s immense gravitational power has been squeezing the planet slowly, relentlessly, steadily, converting gravitational energy into heat, raising the temperature of that rocky core to thirty thousand degrees, spawning the heat flow that warms the planet from within. That hot, rocky core is the original protoplanet seed from the solar system’s primeval time, the nucleus around which those awesome layers of hydrogen and helium and ammonia, methane, sulfur compounds—and water— have wrapped themselves.
Jupiter’s core was far beyond any physical probe. Grant had to be satisfied with equations that estimated what it must be like. But that onion-skin ocean of water, that was his domain now. He was determined to learn its secrets, to probe its depths, to resolve its mysteries.
Grant’s task was to learn as much as he could about that huge ocean. The first crewed mission had failed disastrously because they had been unprepared for the conditions to be found down there. Grant drove himself fiercely to make certain that the next human mission into Jupiter’s ocean would not end the same way.
There were currents in that sea, swift vicious currents that tore through the planet-girdling ocean, ferocious jet streams racing endlessly. With the heat flowing from deep below, the Jovian ocean pulsed and throbbed in constant turbulent motion. Storms raced across its surface and roiled the sea with the energy of a million hurricanes.
Muzorawa spent very little time in the lab now; almost his every waking hour was taken by his training for the probe mission. The Sudanese physicist dropped in to the fluid dynamics lab now and then, but for the most part Grant worked alone, struggling with the attempt to map out the major global jet-stream patterns. At first Grant had been upset by his mentor’s increasingly long absences, but as the weeks ground past, Grant realized that Zeb trusted him to do the necessary work. I’m freeing him for the deep mission, Grant told himself. If I weren’t here to do this job, he wouldn’t be able to prepare for the mission.
Late one afternoon Muzorawa stepped into the lab and sagged tiredly into the empty chair next to Grant.
“How goes the struggle, my friend?”
“You’d think that someone would have solved the equations of motion for turbulent flow,” Grant complained, looking up from his work.
“Ah, yes, turbulent flow.” Muzorawa flashed a gleaming smile despite his evident weariness. “In all the centuries that physicists and mathematicians have studied turbulent flow, it still remains unresolvable.”
“It’s chaotic,” Grant grumbled. “You can’t predict its behavior from one blink of the eyes to the next.”
“Is that a new unit of measurement you’ve invented, the eyeblink?” Muzorawa chided gently.
Grant saw the weariness in Zeb’s red-rimmed eyes. “No,” he joked back, “I think Galileo invented it.”
“If you could solve the equations of turbulent flow you could predict the weather on Earth months in advance,” Muzorawa said, stroking his bearded chin. “That would win you a Nobel Prize, at least.”
“At least,” Grant agreed.
“Until then, you must do the best you can. We need to know as much as possible about the currents and how they change with depth.”
“I’m working on it,” Grant said, without feeling much confidence. “But the data points are few and far between, and the mathematics isn’t much help.”
“Situation normal,” said Muzorawa. “All fucked up.”
Grant flushed with shock. He’d never heard Muzorawa use indecent language before.
“I’ve got to get some sleep,” Zeb said. “Dr. Wo’s been driving us all very hard.” He struggled to his feet, then added, almost as an afterthought, “And the Old Man is pushing himself harder than any of us.”
Grant got out of his chair. “Wo’s driving himself? Why?”
With a weary smile, Muzorawa explained, “He intends to lead the mission. Didn’t you know?”
“You mean he’s going to go with you?”
“That is his intention.”
“But he can’t walk! He can’t even get out of his chair.”
“Yes, he can. The therapies are beginning to help him, at last. He can stand up by himself now—with braces on his legs.”
“He can’t lead a mission into the ocean in that condition.”
Muzorawa started for the lab door, and Grant saw that he himself was not walking very well. With a shake of his head, the Sudanese replied, “He claims it doesn’t matter. We really don’t need our legs inside the craft.”
“You don’t?”
“We’ll all be immersed in pressurized PFCL. It’s the only way to survive the gravity pull and the pressure of a deep dive.”
“What’s PFCL?” Grant asked.
“Perfluorocarbon liquid. It carries oxygen to the lungs and removes carbon dioxide. We’ll be breathing in a pressurized liquid.”
“You’ll be floating, then,” Grant said.
