December 16, 2046, Enceladus
A farmer who had a goat, a wolf, and a head of cabbage with him wanted to cross a river. The boat was so small he could take only one of the animals or the cabbage at a time. How would all of them get safely to the other shore? Martin thought about this ancient riddle as the four of them discussed moving into Valkyrie. The solution was a bit easier than in the case of the farmer—Martin and Francesca walked to the drill vehicle and entered it through the main entrance on the roof. They activated the life support system and pressurized Valkyrie. Then they took off the suits they had come in and entered the spacesuits belonging to Valkyrie via the SuitPorts. Protected by these, they reentered Valkyrie after they had depressurized it by remote control. They picked up the suits they had arrived in and carried them back to the lander, where they reattached them to its SuitPorts. Then they would return to the drill vehicle and the trip could begin.
Every journey begins with a farewell. Martin had imagined the scene dozens of times the night before. He had tried to imagine what words he would use when saying goodbye to Jiaying. Now it is all different, though. He started saying the words he had come up with, but they sounded so hollow. I am helpless because I cannot describe what is happening inside me. And I have a guilty conscience because I am afraid of—but also looking forward to—the coming time, even though Jiaying cannot accompany me.
The solution was incredibly simple. Before stepping inside his spacesuit, he hugged this woman, whom he still did not know very well, drowning in this embrace, and everything was good and right. When he let go of her, he felt his eyes welling up. Jiaying turned away. He noticed she touched her cheeks with one hand. This was the signal to jump into the SuitPort. The visor fogged up when he went outside. This must be from the sweat from my short work-out on the stationary bike earlier, he thought.
“You put your right foot in, you put your right foot out, you do the Hokey-Pokey, and you shake it all about.” Strange that right now a children’s song should go through my mind. It was so odd he almost laughed at himself. He had to control the urge, because otherwise Francesca would think he was suffering from symptoms of the bends. Click. Now the suit from the lander was back in the port. They walked the 30 meters to Valkyrie one last time, connected to the system, and went inside. Martin looked around carefully. Theoretically I can still cancel, can flee, retreat, but I know this is not truly an option. He would stare into the eternal darkness with Francesca. She was the world’s best pilot, and no one knew the Valkyrie system like she did—at least no one less than a light hour away—in other words, some of those pilots back on earth.
“Commander to Valkyrie, starting laser,” Amy's voice said from the mothership.
Martin adjusted the camera so he could see the concentrator. The green ray was there.
“Energy supply at 100 percent,” Francesca reported. The newly focused ray of light moved through the fiber-optic cable attached to the concentrator and into Valkyrie. Here the energy was transformed into heat. The heat became electricity, and when Francesca activated the jets the heat melted ice into water. Then the ray heated it to water vapor, which produced more electricity via a generator, and at the same time melted the ice ahead of them, wherever the jets were aimed.
“Permission to start granted.”
“Thanks, commander, we will see you later.”
At the moment, no further words were necessary. Francesca had all the important data on her screen, and Martin watched the displays. Valkyrie started to tilt forward. Way back in the Antarctic this looked impressive when seen from outside, he recalled. Now, only the walls around him moved, while the seat and the console were mounted in such a way they would pivot to stay horizontal. After ten minutes he was no longer sitting inside a tube; he was now in a tower, without having changed location. Valkyrie dug into the ice with increasing speed.
“All systems normal,” Francesca reported to the mothership and the lander, even though their fellow astronauts saw all data in real-time. “Have fun up there. Rossi, out.”
After moving within the drill for almost two hours, Martin dozed off in his seat for the first time. The background sounds on board were soothing, and it was so different from being in space. The vehicle rubbed against its surroundings, the water vapor jets howled, the intensity of the noise varied, but he no longer felt like a tiny speck in a vast emptiness. It seemed to him that humans were not made for staying in a vacuum. The ice around them was powerful, true. It could squash then immediately if there were tectonic forces, but it was not infinite. It had a limit and dimensions, and humans were in principle able to reach those limits and, even better, go beyond them.
Their limit was at a distance of 5,000 meters from the surface. When he awoke from a confused dream, it was still 4,800 meters away.
“Well, are you back?” Francesca gave him a friendly smile. “If you want to, you can lie down properly.” She pointed to the folding beds hanging from the wall farther up. Martin shook his head, rubbed his eyes, and stretched.
“Thanks, but that’s not necessary. But if you are tired...”
“Maybe later,” Francesca replied.
Martin looked at his watch. They had been going for a little more than two hours. A hundred meters per hour—not bad, compared to what Stone had managed to get out of Valkyrie earlier. Martin massaged his temples. He felt a slight headache, maybe because of the dry air. They had traveled for over a billion kilometers, but the engineers had not managed to provide a comfortable atmosphere. He tried to recall what he had dreamed of, but he had forgotten most of it. I still remember one image, though. I am tied to something and experiencing incredible pain. Yet instead of crying or screaming, I always yelled, “I, I, I.” Sometimes the brain produces strange short-circuits.
Martin sighed. Another 48 hours. This was not a long time compared to the year they had needed to get here. What will the ocean under the ice reveal to us? he wondered. The exobiologists hoped for primitive cells like the ones that existed in hot vents at the bottom of Earth’s oceans. The result of the ELF probe had been, as they say, open to interpretation. A dead hare would be interpreted as a proof of life by any examiner. A frozen single-celled organism, if it was differentiated enough, was only a clear indication. The risk of a chance discovery was low, as the probe had identified several identical specimens. Yet despite all the complexity, those could still be the results of a chemical or geological process that was just unknown on Earth. They could only be sure if they caught life red-handed, when it was currently growing and multiplying.
In two days, their search for life would begin.
December 18, 2046, Valkyrie
Martin had felt as if they would never get through the ice. Of course the instruments had shown they would soon break through into the ocean—radar, lidar, even by the speedometer. With increasing temperatures, the ice had become softer by the hour. At first it had been harder than steel, then like limestone, and finally the jets had cut through it like butter, which saved them two full hours at the end.
They did not see the new world, though, until it happened.
Martin heard it, even before Francesca could tell him. The jets had abruptly become much quieter. They had completely changed their mode of operation. Instead of ejecting hot water, they now sucked in the salty ocean water. And instead of using the energy of the water to generate electricity, the blades of the generator now functioned as a propeller driving the ship ahead, still fed by the laser beam from space. At a signal from the on-board AI, the mothership had reduced the power of the laser, since they needed much less for navigating in water.
It was time to look around. The vehicle activated powerful flashlights that illuminated their surroundings in various wavelengths. Radar and lidar recorded the structure of the ice layer above them, though these sensors did not reach to the bottom of the ocean from here.
The first images started to appear on the large display that substituted for a window at the bow. Francesca looked at Martin. Sh
e is as impressed as I am, he noticed. Above them, somebody had built an ice palace. Trenches, ridges, craters, walls, columns, mountains—the lower aspect of the ice seemed to mirror the shapes on the surface. All that was missing was a copy of the lander. An exotic mirror country stretched above them far into the distance—shiny, crazy, and clinically pure. Even the water appeared to be clear as crystal.
Martin remembered his last visit to a cave on Earth. Wherever I looked, life was spreading. Moss, lichen, layers of bacteria, primitive plants—even under such unfavorable conditions, they displayed a great variety. Nothing like that can be seen here. They were moving through an amazing but apparently sterile world that might even be hostile to life.
With mouths agape, they continued to watch new, seemingly impossible structures, while Valkyrie drove like a submarine toward the South Pole. The work of art above them was art for art’s sake, as the searchlights of Valkyrie were doubtless shining light on them for the very first time in their existence. It appeared Francesca and Martin were the first intelligent beings in the universe allowed to marvel at this masterpiece of sculpture. This is an incredible gift, one that will always connect me to the pilot and to this moon, he mused.
Soon the on-board AI started its automatic search routine. The two astronauts did not have much to do. The first images were sent—via the laser uplink—to the spaceship, and then they left this world. A few hours later the first congratulatory messages arrived from Earth, though worded rather cautiously, particularly when exobiologists had sent them. After all, they said, they had not expected to find a second Earth here. What the experts did not add was, but it would have been nice, of course.
The two astronauts were not bothered by this. The searchlights were first switched to infrared and then to ultraviolet, and each brought more fascinating effects. Now they observed ribbon structures they believed to be different phases of the ice. Martin spent half an hour describing to Jiaying via a dedicated line what splendors he was seeing. Shortly before the end of their conversation, she told him she had kept the channel open for Hayato, so he could listen in. Martin did not mind. He gladly shared what he was experiencing.
After twelve kilometers below the ice, the sensors reported increasing currents. The engines could easily handle this, though. They appeared to be approaching one of the Tiger Stripes, the source of the ice geysers that made Enceladus such a unique place in the solar system.
The abyss opened at kilometer 14.8. It was a deep structure that looked like it was cut by a knife. The searchlights did not reach the bottom—if there was one. It must be at least 750 meters downward, Martin estimated. At the edge of the area lit by the searchlights they saw hints that the ice was not perfectly clear everywhere. They could not be sure, but those areas might be deposits of organic material. Jiaying urged them to go there right away, and a few hours later the scientists on Earth concurred emphatically. However, the two astronauts stuck to the plan—first explore the surroundings, then set priorities, and only afterward decide to follow up on specific phenomena.
Valkyrie followed a curving course and finally returned to its starting point. The vehicle plowed through the ocean like a whale. The water streaming through its engines was examined in all wavelengths. For each cubic meter, a milliliter was sent to a rapid analyzer. This allowed the AI to create a rough map of chemical distributions. The water was very salty indeed, much more so than in the oceans on Earth. Even though the salt water looked clear, it contained a certain percentage of organic material that might be of chemical or biological origin. The consistency was not uniform, as there was a gradient that increased with depth, and a second one that correlated to their nearness to the Tiger Stripes.
In general, the water did not contain a lot of minerals, except near the currents leading to the stripes. It appeared logical to the scientists that the mineral content would rise with increasing depth, as this is where the ocean met the rocks. Nowhere else could salts be dissolved into the water. The collective exobiologists on Earth could not agree on what further course Valkyrie should take, so Martin and Francesca went to sleep, leaving the exobiologists to argue among themselves.
Age of Questions, Point
There is:
The I.
The all.
The warmth.
The salt.
The movement.
The current.
The force.
The effect.
The beauty.
The order.
The time.
There is not:
The not-I.
The not-all.
There no longer is:
The eternity.
There is:
The doubts.
There is:
The questions.
This is the age of questions.
It starts with a point.
December 19, 2046, Valkyrie
Watson woke them at 0800 hours ship time. The smartest people on Earth had decided the voyage should continue downward, into the depths of the ocean, all the way to the bottom. Martin mentally prepared for a period of boredom. Valkyrie tilted its nose, but due to the low gravity, he barely noticed it. Their seats and displays adjusted automatically. There was a brief moment of pressure, and then the vehicle moved at a constant 29 kilometers per hour. They would not have noticed their progress without the instruments that measured the distance covered. The cameras showed the same image from all directions.
Martin asked the AI to display what had been found so far. The list of chemical molecules was long. First, Martin quickly scrolled through them. Maybe there was a pattern the software had overlooked. The crucial question was, could the origin of these compounds be explained purely through chemistry, or was there something that required a biological explanation?
Martin noticed very little ammonia was dissolved in the water. The ice cores of comets that originated during the formation of the solar systems had a significantly higher percentage of ammonia. The ocean must, therefore, be very old to have had enough time to release the now missing ammonia via the Tiger Stripes.
Martin and Francesca seemed to be moving through a reservoir of water older than all of the oceans on Earth. If there was life here, it would have had a lot of time to evolve toward perfection. Scientists had already suspected the water was saltier than in most bodies of water on Earth. Valkyrie reported a current pH value of 11.1, which was slowly increasing with their depth. In the Al Hajar Mountains in Oman there is a mineral called ophiolite that had, in ancient times, been exposed to water with similar pH values. Tectonic movements had formed the mountains, transporting the ophiolite from deep in the Earth’s crust to the surface. The high PH level found here was another indicator that the ocean on Enceladus was enormously old.
This raised another question. From studying the formation of ophiolite, it had been discovered that hydrogen was an important by-product. Hydrogen played a prominent role in the synthesis of organic compounds, and also provided energy for life. If these processes were still ongoing, this ocean, particularly its floor, would be a livable home for microorganisms. Even though I would like to look at the dark sediments at the root of the Tiger Stripes, I can fully understand the decision of the scientists on Earth, Martin reflected.
“Are we there yet?” he asked.
“Yes, my boy, have a little patience.” Francesca played along with the game indicated by Martin’s tone of voice.
“I have to go potty.”
“Just a moment, I am looking for a place to park.” The pilot turned the nose of Valkyrie, as if she was looking for an exit from a highway.
“Approaching solid ground,” Watson reported. At the same moment, Martin saw a fine line appear on the radar display.
“Just the right time,” Francesca said. “We are sure to find a bathroom for you down there.”
It took a few more minutes before they established visual contact. What they saw was completely different from the scene below the ice. Martin was surprised, e
ven though he should have known better. The stone below them, which formed the rocky core of Enceladus, was impermeable to searchlights. It did not shimmer or shine. Francesca turned on the infrared light. The image did not change. She activated the normal searchlights again, but left the infrared camera on.
“Oh!” Martin blurted out. Francesca froze. Several patterns appeared on the screen, and she increased the contrast.
“There are temperature differences of several degrees!” Francesca exclaimed.
Martin checked the calibration. Francesca was right. Were there geological processes that created such an image? Maybe cracks in the rock that transport more heat from the interior than their surroundings?
“Watson, I need an in-depth analysis.” Martin had to find out whether the temperature differences conformed to the structure of the rock. This would be the simplest explanation, but we also have to watch out that our desires do not dictate what we see.
Since she was the pilot, Francesca was required to confirm the order. Then Watson bombarded the area below them with everything their vehicle could muster—gamma rays, x-rays, terahertz, UV, radio waves. These channels had different penetration depths, depending on the rocks, temperature, pressure, and so on. A very precise image of what lay below them would be generated once these measurements were combined.
The calculations took a while, even though they also used the main computer which was connected via the fiber-optic cable. After seven minutes and thirteen seconds—Martin had followed the time with the seconds-display of his watch—they received a result. The silicate-rich rock met their expectations. They were facing the uppermost layer of a differentiated core. Not every moon possessed such a core. Such a temperature distribution had not been detected on any known celestial bodies, save for Earth. This proved energy was produced, distributed, and consumed here. We have caught life red-handed, even though we have yet to discover living beings.
The Enceladus Mission: Hard Science Fiction Page 22