“It’s nice to meet you. I am The Dog.”
“I know.”
“Not the dog, The Dog,” The animal stressed the second “The.”
“The Dog?”
“Yes, that one—the one you are looking for.”
“Really?” Martin asked.
“Yes. Well, hop on.” The dog was suddenly three times its size. Martin was supposed to get on its back.
“I don’t know.” He hesitated for a brief moment.
“Yes, you have wanted to do this for a long time,” said The Dog.
Martin followed the invitation and sat on the dog’s back. A hissing sound could be heard, and in front of them a hole opened up in space-time, its edges flickering.
“Go,” Martin said. The dog obeyed and jumped. They fell into a tunnel that looked like it led through an aquarium. Large, smiling fishes were gazing down at them. The dog is running so fast, I’m afraid I might fall off. The water was getting darker and darker, and soon it was black, and the moon rose. It shined a brilliant white. Martin saw snow falling but noticed no clouds.
“I…”
This was the last thing Martin heard. The dog was gone, and he was alone in the darkness. Martin looked around. His body cast a huge, hard shadow. There was a gurgling sound. From the blackness of night, water was streaming, came quickly closer, and surrounded him.
“I…”
Martin could breathe under water. His reflection hung so close to his face that he jerked back.
“Hey, Martin, wake up.”
Jiaying’s hand caressed his shoulder.
“I almost fell out of bed because you were rolling back and forth. I had to wake you up.”
“Thanks, it’s good that you did.”
Martin checked his watch.
“Another hour until my shift starts.”
Jiaying smiled and said nothing. They cuddled up to each other and fell asleep again. Soon their time together would be over, and the exploration of the ice moon would begin.
After breakfast, Martin had a déjà vu moment. They were sitting around the conference table. The fog display presented the shining image of Enceladus in highest resolution. They needed to find a spot where the lander module could touch down.
“Watson has already prepared something.” The commander pointed toward an area near the South Pole. “However, I want you to bring up your ideas, no matter how odd they may seem. The problem is the AI is lacking data for a reliable decision. Furthermore, it might be using different assumptions than we are.”
This had increasingly turned out to be a problem during AI research on Earth. Artificial intelligences easily learned to find patterns in mountains of data. Later the intelligences then further improved themselves by comparing desired and actual outcomes. Yet with issues concerning humans, and that applied to almost all issues, intentions were incredibly important—a concept AIs had a hard time with. Or did AIs develop their own intentions during the learning process, that later interfered with their neutral work?
The suspicion existed, and researchers considered the issue undecided. Maybe Watson, without being aware of any wrongdoing, automatically selected a landing spot that was optimal for its own existence? Of course they could prove nothing regarding the AIs, particularly since they did not know which form of existence an AI would consider to be optimal.
Jiaying pointed at the region around the South Pole and zoomed in with a spreading gesture of her fingers.
“Here we have the Tiger Stripes.” The image showed icy canyons.
“These are crevices in the ice, up to 130 kilometers long. At these crevices, it gets warmer than elsewhere on this moon, minus 93 degrees Celsius versus minus 201 degrees. The distance between them is about 40 kilometers. I am now switching to the UV range and I will increase the contrast.”
It appeared that material came out of the cracks, as if Enceladus was leaking.
She continued her presentation. “This just shows the current state. The places where most of the material is ejected keep changing, and the amount also varies with the orbit of the moon. It might look like that, but the steam does not just appear in a few spots but over the entire length of the crevices. The Tiger Stripes also grow and shift, and they do so in a few centuries. Geologically, this is a very short time.” Jiaying seems to be in her element. As a geologist, she is fascinated by these geysers, Martin perceived.
“What comes out is water vapor. There must be an enormous pressure behind it. The particles are shot into space at 1,400 kilometers per hour. This is faster than the escape velocity, so the particles do not fall back on the moon. The ice crystals then form Saturn’s E Ring. Now, I am switching back to the visible spectrum.”
The image changed and the jets became fainter.
“Where does all this come from? Just a moment…” Jiaying drew a command in the air, and the image was overlaid by a function diagram.
“Enceladus has a stone core. However, it is not large enough to provide heat, like the core of Earth.”
She moved her arm in a circle. The image zoomed out and now showed the rotation of the moons around Saturn.
“Enceladus is in a 2:1 resonance with the moon Dione, which is a bit further out. This means that for every two orbits of Enceladus, Dione finishes one. The periodic action of its gravitational pull, and the pull from the giant planet Saturn in the vicinity, massage the core of Enceladus in such a way that a lot of friction—in other words, heat—is generated.”
Jiaying clenched her hand to form a fist. Now the Tiger Stripes reappeared.
“The heat melts the ice above the core up to a certain height. This creates a liquid ocean below the ice. Minerals from the rocks are dissolved in the water. The ocean is probably rather salty. This is also supported by an analysis of deposits along the Tiger Stripes. Salts and carbon compounds were identified there. These are heavier than ice crystals and therefore they separate from the geyser streams and fall back.”
Jiaying removed the function diagram and took a short break. On the display, Enceladus sparkled like a jewel.
“The best thing," she said upon resuming, "and the reason we are here, is of course because the ELF probe found definitive signs of life. To be more precise, these were cellular structures. In a spectacular maneuver, the probe flew along the Tiger Stripes at an altitude of a few hundred meters and captured the ejected material as quickly as possible, before it could fall back down or could be destroyed by crystallization. At an ejection speed of 400 meters per second, the material would have been in the warm interior of Enceladus only a few seconds before. The measurements were clear.”
Jiaying zoomed in even more on the Tiger Stripes.
“We assume the ice here is only five kilometers thick. Further north, the thickness is 10 to 15 kilometers. Therefore, we should definitely try to land here, unless there is some important factor against it.”
Martin zoomed in a bit closer to the area. The area between the stripes only looked smooth at first glance. Cracks, fissures, plateaus, and plates dominated the picture. “There were arguments in favor of landing further north,” he said.
“Yes,” Jiaying replied, “Watson is also for it. A fresh crater would be ideal. The impact briefly melts the ice, and when it refreezes, the surface is smooth, perfect for a clean landing.”
“But.. ?” Martin interjected.
Jiaying zoomed in even further and displayed a scale.
“The local structures are predominantly level. You see? The fissure here might be about 300 meters deep. The cliff has a vertical height of 200 meters. But the plate next to it is at least 500 meters long and wide. There is more than enough space.”