The Titan Probe

by Morris, Brandon Q.

  She reached the foot of the mountains. Francesca climbed a hill and could not believe her eyes—in the valley ahead of her was a lake that did not appear on the radar maps. Had it formed from precipitation? Francesca could only explain this by the fact that below the thin sand layer there were few places for liquids to drain. The mountain range curving around the lake must have collected all the precipitation, and currents then moved the liquid methane into the valley. As the height profile of the radar images reported, the lake must be less than a meter deep. On Earth, she would simply wade through it. Here, that would be an act with a definitely lethal outcome. She might as well be standing in the methane rain.

  Francesca looked around. The lake was not particularly wide, but it stretched for kilometers from north to south at the foot of the mountains. It almost looked like a river because it was only about 80 meters to the other side. It would take her at least two hours to walk around it. A boat would be more practical, she thought. She had her tent with her. The igloo form was stable, since the NASA engineers had designed the tent in such a way it would keep its shape under very different environmental conditions. The material, which she had already tested in the rain, was impermeable to liquid methane. If she turned the igloo upside down and sat in it, she should be able to paddle across the lake.

  That is, unless she was too heavy. Liquid methane was only half the density of water. For the boat to be able to float with her in it, the weight of the displaced liquid must be higher than the total weight of boat plus passenger. Francesca used her arm computer to calculate the volume of the igloo as a spherical section, using estimated measurements. The results were close. The boat would sit low in any case. She could only hope the lake was not too shallow. Half a meter should be the minimum.

  Francesca calmed herself down. You learn by doing, she told herself. If she sank close to the shore, she would make it to solid ground quickly enough to survive the experiment. Then she would have to take the long way around. She unfolded her tent and held it upside down with both arms. Then she walked as close to the shore as possible. She immediately felt her toes getting cold. She placed the tent on the surface of the methane. It hardly sank into the liquid, but it was still lacking her weight. Francesca checked her gear. She would leave everything behind that she no longer needed—the improvised ice pick, for instance. The small shovel from the emergency bag would serve as her paddle. In front of her were a small pile of her few possessions. She said goodbye to them, since she didn’t know whether she would come this way on her return trip.

  Then she took a big step into her igloo ‘boat.’ She used the other leg to push herself off from the shore, and then pulled it into her boat. The boat wobbled dangerously. Francesca tried to compensate for the movements, and finally the boat sat evenly in the liquid of the lake. She’d made it!

  “Ha!” she involuntarily said out loud. When she looked around, she was reminded of a line from a Christmas carol Martin had taught her. ‘Quiet and frozen rests the lake,’ it said. The lake was really quiet, so much so it scared her. There had only been tiny waves when she stepped into the overturned igloo. Water, she thought, would have reacted differently. She carefully lowered her right hand into the lake. Immediately it felt colder inside her glove. She pulled her hand out again, palm facing upward, and watched the rest of the liquid. The methane was as clear and transparent as the water of the Adriatic. The tiny puddle in her hand disappeared quickly, and she felt the biting cold as the evaporation drew heat from her body.

  Francesca took the little shovel and began paddling. While doing so, she had to be careful not to lean out too far from the center of the boat. She kept her bodyweight as much as possible in the middle and only stretched out her arms. This posture was stressful, though the paddling itself was not. It felt like whipping up foam. She seemed to achieve little, but the boat obediently started moving. Slowly, the opposite shore came nearer. Might there be a current? Shortly before reaching the middle she noticed the boat was moving slightly toward the south. The lake must have an outlet somewhere after all. The current was not very strong, but if there was an outlet she could have just shown some patience, and the obstacle would have disappeared by itself.

  Three meters from the shore her primitive boat ran aground. What now? Obviously the lake was shallower here. She tried to gauge the depth with the shovel and hit bottom after 30 centimeters. She could sit here until the lake drained by itself, or she could wade quickly to land. It wasn’t far, after all. Four or five steps through the deadly cold should be enough. The suit heating should be able to handle it. Francesca knew she would have to climb out, grab the boat, and then get to the shore as fast as possible.

  Then she turned her plan into reality. She knelt in the middle of the boat and then got out backward. The boat was wet and heavier than before. She still could lift it effortlessly before the pain of the cold moved up her feet. She turned around and jumped like a hurdler. With each of her long steps methane splashed—and then she reached land. Francesca’s heart was pounding. She put down the igloo, then bent forward and rested her hands on her knees. After a minute and a half she had caught her breath enough to look at her watch. The boat trip had taken less than twenty minutes. Methane vapor rose from the lower part of her spacesuit. The heating system was working at full blast. She carefully moved her toes, and was relieved to find they didn’t seem to be frozen. According to the radar map, there should only be a small range of hills between her and the Huygens lander. These were low rises, at most 50 meters high. Francesca decided to wait until she reached her goal before taking a break.

  January 1, 2047, Titan

  “Happy New Year!” Martin woke up when Hayato touched his shoulder. He must have dozed off for a few hours. “Excuse me, I did not want to wake you up,” Hayato said, “but I thought we should at least welcome the New Year.”

  You have no idea how little I care about it, Martin thought, but he did not say anything. Somehow Hayato’s words touched him strangely, anyway.

  “Happy New Year to you too, of course,” he said after a while. “What is it like to be a new father?” Martin felt he should exchange a few words with Hayato while they waited for Francesca to return.

  “It is... strange,” the Japanese astronaut replied. “I know I should probably say it is great.” Hayato seemed to have been waiting for this very question. “And it is really fantastic when Dimi smiles at me. But it is also somehow odd. You know—this little human being is going to be my son from now on and forever. It is not like a marriage because it cannot end.”

  “Were you ever married?” asked Martin.

  “Yes, but we did not have any children. Concerning my son, I really have to get used to it. I always thought one would automatically know what is right, but that is not the case. I am so important to him, but I do not feel sufficiently prepared.”

  “But you love him, that is the main thing.”

  “I do not know. I am starting to get really worried about him. It was my fault he was born aboard a spaceship. Since his birth he has been in constant danger, and who knows how he will fare on Earth? He has never experienced such a strong gravity. He might have just learned to walk when a force he will not understand will press him down.”

  “It’s not your fault he was born in space.”

  Hayato laughed. “Well, you cannot really say that. To be honest, I am afraid I will not be able to fulfill my paternal duties.”

  “Did you talk about this with Amy?”

  “No. She already has so many responsibilities. It would just stress her even more.”

  “That’s nonsense. You have to talk to her.” Martin would never have thought the time would come when he would offer marriage counseling to anyone. Especially Hayato, of all people. However, the answer seemed perfectly logical to him.

  Hayato nodded slowly.

  “And I also think you are a great dad,” Martin said. Better than mine, for sure, he thought to himself.

  “Just a moment.” Hayato
got up and walked to the monitor showing the image captured by the outside camera. “Please come and take a look at this.”

  Martin went and stood next to him. Was he mistaken, or had the wall moved closer? He checked the camera settings. The zoom factor appeared to be unchanged.

  “How odd,” he said. “Let’s compare this.” He paused the image and used a finger to rewind it. At normal speed it was hardly noticeable, but in time-lapse mode it became clear the wall was growing and moving forward.

  “We should inform ILSE,” Hayato said.

  “Come on, we shouldn’t be afraid of a bit of sand,” Martin replied. “But what could it be? Is it related to the tides? The ice crust has a tidal range of more than ten meters.”

  “That could not be the cause. The tidal deformation is much broader. Under these lighting conditions we would not even notice it. Maybe we could see it from above by radar, but definitely not as a limited wall. And look… the structure is curved. If I am not completely mistaken, it is right now trying to encircle us.”

  Martin uttered a short laugh. A bunch of ice grains surrounding a spaceship! “Hayato, I think we are both a bit overwrought. It has been a stressful day. I am sure some natural phenomenon is behind it. Doesn’t Titan also have an ocean below the ice? Maybe we landed near a fracture. The lander module came down pretty hard, if you remember. This changed a fragile balance that might have been waiting for just such a disturbance—like a snowball being thrown into an avalanche field. And now a process has started that will create a new equilibrium.”

  Hayato followed Martin's argument and pensively rubbed his chin. “Maybe,” he said. “But if the person throwing the snowball is in the wrong position, he will soon find himself inside an avalanche, a chaos of snow and ice. Then he will not live to experience the newly created equilibrium.”

  January 1, 2047, Titan

  Even 50 meters could feel quite high, Francesca noticed, while she looked around. She was glad she wasn’t prone to vertigo. In front of her was a valley, even wider than the one she had just crossed. It seemed to be mostly dry, though. Obviously, there had been no rain here. There also were no dunes, just randomly distributed rocks of various sizes. The landscape resembled a dry creek bed or a stony desert on Earth. The sky was the same dull brownish orange it had been the whole time. The haze grew thicker again.

  Francesca looked at her map. The blinking dot on it must be about 1,500 meters away, at the three-o’clock position. She tried to get a glimpse of it through her binoculars, but could not recognize anything. Then she switched to the infrared spectrum. The image became more coarsely grained, but now she could detect a bright spot at this location, which must be warmer than its environment. She could not tell the exact temperature difference, but it could hardly be more than twenty degrees.

  It had to be Huygens. But where did the heat come from? According to NASA, the internal batteries should have been drained for 40 years. The probe did not possess any other source of energy. Maybe it was a chemical reaction, Francesca mused. The casings of the batteries had been exposed to the corrosive atmosphere for many years, and this might have finally caused a short circuit during the last few days. Francesca knew very little about battery chemistry, but she considered it possible there had been a reaction with components of the Titan atmosphere that created electrical energy. Weren’t ions—electrically charged particles—intermediate products of almost every chemical reaction? Huygens might have used these feeble residues to start the radio system. Francesca knew it was part of the probe’s programming to transmit signs of life for as long as possible. This would be a remarkable proof of the engineers’ skills.

  Well, no use lingering, I have to check on it. Francesca took off at a brisk pace. The hard ground made walking easier. The pebbles burst under her steps. They obviously consisted of smaller fragments baked together, more like tiny snowballs than granite pebbles. There were few orientation points in this area, basically a desert, so now and then she checked in infrared to assure she was still maintaining the correct course. After a march of twenty minutes she saw with her own eyes what she was walking toward. It was a low hill. On top of it was an object looking like a large black clam with its shell closed.

  Huygens. There it was. Twenty meters before reaching the goal the ground became sandy again. Then she stood in front of the module ESA and NASA had landed on Titan over 40 years ago. She was impressed by this feat, since Huygens looked rather primitive—a truncated cone with a diameter of about one and a half meters and a height of less than one meter, sitting on a large pile of sand, as if on a pedestal. Francesca lifted one side of the probe. It was surprisingly light. The metal it was made of was no longer shiny, and now it was covered by a thick, brownish film. Some of it stuck to her glove. She tried to wipe off the coating on the top, but it was too tough.

  Nothing indicated the probe was still active or had recently been so, even if Earth received a signal sent by it. She assumed she would not be able to solve the secret of this radio transmission. She could hardly carry Huygens away to be investigated later, since the lander was too unwieldy to consider carrying it. Unfortunately, there were also no log files to be secured—Huygens had saved no data on board. Due to its low chances of survival, this had been considered unnecessary 40 years ago. Just to be on the safe side, Francesca once more switched to the infrared visor. Scattered across the entire probe she saw small, bright dots. Those must be the encapsulated plutonium pellets that kept the most important sensors warm. They still gave off heat from radioactive decay, but generated no electricity.

  Francesca took a step backward and noticed something surprising. The sand pile which Huygens sat on was about five degrees warmer than its surroundings. By itself this was not surprising, but there were several heat channels running below it, beneath the top layer and into the ground, from the probe. It looked as if Huygens had grown invisible roots connecting it to the moon. Completely impossible, Francesca thought. She recorded what she saw, because otherwise no one would believe her. Too bad they could not have landed closer to Huygens. Then they could have thoroughly investigated the phenomenon. Perhaps there was also a physical cause, such as some leaking liquid reacting with the environment. Francesca shook her head. Back on Earth, smarter people than she would have to wrack their brains over this one. She walked around Huygens several times to document her finding from all angles. Then the arm computer reminded her it was time to start the return trip.

  January 1, 2047, Titan

  “Lander to ILSE,” Martin reported.

  “This is Amy. Hope you had a good New Year’s Eve.”

  “Sure, we had a huge party down here. My head is still aching.”

  Amy laughed. “The same with us here. At our age these drinking bouts are no longer appropriate.”

  “Though that wasn’t the main reason for us to wake you guys up.”

  “I really hope so. What’s up? Has Francesca returned yet?”

  “Not yet. We had our last radio connection about…” Martin checked his watch, “six hours ago.”

  “No reason for concern. She must be in the radio shadow of a ridge. That was to be expected.”

  “I am not calling you because of her.”

  “What then?”

  Martin wondered how best to say this. “Could you aim the radar at our landing site?”

  “One moment.” He heard the commander typing something. “Sorry, but we won’t be back in radar range for another two hours.”

  “I understand,” Martin said. “Then you will just have to believe what I am going to tell you.”

  Amy chuckled. “Well, don’t keep me in suspense. Of course I am going to believe you.”

  “Well, it is not so funny down here,” Martin replied. “Around the lander module... a wall of ice sand has formed, several meters high. I am uploading the images to you. We still don’t have any idea what this might mean. It also wouldn’t seem so threatening if it did not continually come closer.

  “It does
sound strange. Give us a bit of time to look at the images. Let’s also see what Watson has to say. Maybe it’s some weather-related phenomenon?”

  “Don’t take too much time.” Martin tried to hide his nervousness, but failed to do so. “If this goes on, the wall will be right at the foot of the lander 45 minutes from now. And of course, I wonder... what will happen then?”

  Amy did not answer.

  “Commander?”

  “Please give us five minutes. I’ll call you back. Amy, over.”

  “Of course they do not have a plan yet.” Hayato looked at him. “We need more information.”

  “And how would we get it?”

  “Martin, we are researchers, so let us research. What types of sensors do we have here?”

  “Only what the lander needed for the descent. After all, it is not a research station.”

  “Just a minute, though; we could analyze the atmosphere, for one instance.”

  Hayato was right. “The gas chromatograph,” Martin said. “You mean we should simply check what the wall consists of?”

  “ILSE to ground team. We’re back.” This time Jiaying spoke.

  “What have you got for us?” Martin felt all warm inside just hearing her voice.

  “We can exclude a normal weather phenomenon. However, Titan has not been mapped during all seasons. Up until now, no probe has orbited it for a whole year.”

  “I don’t know what you are aiming at.”

  “It is currently fall. Maybe this is a rarely occurring local phenomenon. Like tornadoes on Earth, or the Great Red Spot on Jupiter. Here everything moves more slowly, so perhaps the tornado becomes a circular wall.”

  “I am not convinced.” Martin would have liked to have given her a different answer.

  “We thought so. To be honest, Watson rates the probability of it being a natural process very low. Below five percent.”