Sometimes the natives aren't friendly to visitors
Edited - about 2000 words
"Landing sequence for Europa starts in eight minutes." Teron Lachance's voice was calm, as though our thirty-month voyage to Jupiter's sixth moon had been a Sunday drive. Calmness under pressure is a good quality in a mission commander.
"Teron, I'm seeing a bit of vortex turbulence a few kilometres north of the landing site. Dmitri, you're our exometeorologist. Check Display 15. Any concerns?" Berit Olsen sounded a bit excited, as was I, though we strove to mimic the stolid Teron.
"Got it, Berit," I said as I studied the display. It had been known for decades that Europa had a tenuous oxygen atmosphere, and it was no surprise to find whirlwinds; they'd been seen on Mars as well. Our advance drones had shown one or two, here and there around the cracks in the moon's icy mantle, but none at the proposed landing site. Yet, here they were.
"Atmospheric pressure and wind velocity are all good. The vortex activity is well out of the way, and looks minor, barely enough to show up on the scan. Shouldn't be a problem." How little I knew.
"Thank you, Major Olsen, Doctor Kovalenko." Teron was being formal in honor of the occasion. "It is time. Landing sequence is go... Now."
= = =
On Earth, minor vortexes are disrupted easily when they encounter an obstacle, so we had accepted the computer-chosen landing site and just ignored the whirlwinds. That was our first mistake.
When we left the lander and began to set up the Station under the incredible bulk of Jupiter sailing above us, there were perhaps a half-dozen whirlwinds to greet us. They ranged in diameter from willowy straws to metre-broad swaths of air, in height between waist-high to perhaps twice a man's height. They would pop up in the middle of nowhere, wander around the site for a while, and then dissipate into little piles of dust and ice crystals.
"It is almost like they are coming to check us out," laughed Teron. We had unloaded the first bubble, the commons module, and its dull gray material looked clean and foreign against the dirty ice. I looked around, and decided he was right. The little spinners held further back, racing from side to side like excited puppies. The larger ones, more daring, came closer, their movements seemingly more purposeful.
"Kind of like a bunch of neighborhood kids watching a construction crew, right, Berit?"
She glanced at the little whirlwinds and agreed. "Ja, Dmitri. Like my brothers in Norway, dancing around a grass snake, daring each other to grab it." The three of us cleared the site and staked the bubble down on the ice. Teron pushed the button to start the chemical reaction that would auto-inflate it. As it slowly grew, we went on to the next task, while keeping a curious eye on the little vortexes. We considered them harmless and we compared them to puppies and children. That was our second mistake.
Within three days, ship time, we had completed the commons bubble and initial setup. The little fusion plant was busy providing heat and power to counter the blistering cold, the collectors were compressing atmospheric oxygen, and the converter was mining ice for future rocket fuel. Soon we would set up the next two bubbles and move in.
We were growing tired of being sardines in the tin can of our lander and were looking forward to the relative roominess of the three bubbles, which were basically kitchen/dining/common space, research lab, and habitat/sleeping quarters. We got along well (we had to, for the trip here) but it would be good not to have our elbows up each others' noses.
"Heavens, look at those things," Teron marvelled as we moved from the lander to the habitat bubble. There were half a dozen whirlwinds lining our path. Berit swiped at one with her glove, and as we expected it broke apart. The others danced back as we walked to the bubble airlock, then crowded in behind us as we entered.
"That's creepy," she said. "They almost seem to show curiosity." We paid little heed, and that was our third mistake.
We completed the Station and settled in to our mission of exploring the most likely second place in the solar system where life might be found. Moving was easy in the low gravity, despite our thermal suits. We set up seismometers to confirm the theory of a liquid water core. We measured ice depth. We sent out drones to map the narrow surface cracks. We collected and tested ice and air samples. We recorded atmospheric measures of oxygen, water vapor, and other gases. Wherever we went, we were accompanied by a little ice-devil or two.
"You could argue that they show signs of intelligence," marveled Teron during one out-trip, "like they were observing us."
"Or as I once said," added Berit, "curious about what we're doing."
"Nonsense," I objected. "How could a local wind disturbance possibly have intelligence? Or even the means or mechanisms for intelligence? It can't even show the signs of life -- respiration, ingestion, excretion, reproduction."
"It certainly shows motion," Teron argued, "and you might consider that it ingests and excretes dust and ice crystals. And the fact that they follow us suggests an awareness of the environment."
"I think you're both anthropomorphising. And mistaking coincidence for causation."
Our discussion of the impossibility of intelligence continued off and on for days. It was more entertainment than serious consideration. Perhaps that was our fourth mistake.
= = =
When the research bubble popped, we were all in the commons, which may have saved our lives. "What on Earth--" Berit yelped. "Micrometeorite? Material failure?" She sealed her suit automatically and turned to the control display.
"Watch the corridors, Dmitri," Teron ordered. I helmeted up and checked.
"Panels down and sealed," I reported. Although our had ears popped with the pressure drop, we lived.
"Air and power nominal," Berit chimed in "Lab pressure down but no breach." Because the bubbles were on a parallel circuit for power and air supply, any one bubble could sustain us. Although with the food all in the commons....
"Okay, pressure is holding, that is good. Berit, watch the board, especially power and compressor feed. Dmitri, you and I on exterior reconnaissance."
We exited the airlock into a flurry of little whirlwinds. Like a flock of bloody starlings, I thought. We plowed through them, scattering cascades of ice crystals and dust. Was it only my imagination that our suits began to look...polished? worn?
The lab bubble was not badly damaged. One section of the outer layer appeared to be abraded, worn thin, and inter-layer pressure had bulged and popped this weakened area. The inner layer had held but the loss of suspension pressure had triggered the alarm and closed the corridors.
"We will need a patch," said Teron. He kicked at the piles of ice crystals at the base of the bubble. "Check the other bubbles, Dmitri. I will go for the patch." He radioed Berit that he was headed to the lander, where the patch materials were stored.
I began to circle the station, checking bubbles and corridors. I found several more abraded areas, each one just above a small pile of ice crystals and dust. As I came around the final bubble, the commons, I encountered an icy whirlwind half again my size. It was somehow snuggled against the bubble, rubbing up against it without being disrupted.
"Get out of here, critter!" I charged into it, waving my gloves. I could feel the pressure of wind and ice on them as the vortex collapsed. When I examined the bubble plastic, I could see where it had been scored and worn by the rubbing of ice and dust. I radioed Teron with the location, adding, "Bring extra patches. And we need to talk."
I ducked back through the airlock. "We've got problems," I announced to Berit.
"I'll say. For some reason, the exterior atmospheric pressure has almost doubled and the wind speed is up almost as much."
"That can't be right. Static air pressure and air velocity are inverse. If the pressure goes up, the wind speed goes down."
"On Earth, yes. This is Europa. The relative humidity is up, too. Surface ice is sublimating into the atmosphere in greater quantity."
"Any danger to the station?"
"Well, the ice plate isn't going to dissolve under us. But the atmosphere is becoming denser and there's more air and wind pressure on the bubbles. With the wind rising, the drones are coming back on auto-home."
By then, Teron had placed the first patch and was re-inflating the lab. Berit radioed him, "Teron, you'd better come in and take a look at the videos from the drones. We've got a lot of vortex activity on the side away from you."
A lot, indeed. By the time Teron was back inside, we were surrounded like Custer at Little Bighorn. The drones showed a dozen good-sized spinners clustered around the station, taking turns moving in close and rubbing a spot on a bubble. When one whirlwind collapsed, another moved into its place.
"Son of a bitch!" Teron growled. He flew a drone around the station, dissolving every whirlwind it touched, but others quickly sprang up. "It is absolutely impossible but the damn things are intelligent. We are under attack. Everybody suit up. Berit, get all the spare tanks and power packs charged, stat! Dmitri, how are the bubbles?"
"Commons is almost worn through, needs a patch pretty soon. Others show wear. Corridors too."
"Damn. We don't have enough patch to cover everything. I guess they would just wear through if we did. And the rising wind is picking up ice crystals and getting to be like sandpaper even without those ice-devils chewing at us."
"Berit will get this all into our report." I nodded to her.
"Ja. It will go out with the next burst."
"Yes, it will let Mission Control know our situation. Some help to the next expedition. But we are on our own."
"What about the lander?" I wondered.
"Showing signs of wear, though there were no vortexes around when I was there for the patch."
= = =
When the commons bubble popped, we transmitted our last burst, loaded up the compressor and some food, and headed for the lander. The whirlwinds followed us and may have tried to rub on us, but we were too quick moving. We could just wave or walk through them and they were gone. So we worked relatively unimpeded to re-install the compressor and begin pumping oxygen into the lander's tanks.
"Too much water vapor in the air," complained Berit as we settled in and stowed what food we had brought. "Filter is overloaded. It can't drain fast enough."
"Well, at least we won't die of thirst," I joked.
"Dmitri, we will die on Europa."
"It was always a possibility. We knew that when we signed on. We only hoped we could survive six months until the next mission arrived."
"Look at the radar," Teron said. We looked. The display showed eight large vortexes converging on the lander, with larger ones in the distance. Impossible atmospheric conditions with impossible consequences.
"How long can the lander last?" I wondered out loud.
"Not long enough." Teron set his service pistol on the comm desk. My heart chilled. I knew what he meant.
"Can you do this, Teron?" asked Berit. "Will you do this for us?"
"I am in command. If I have to, I will."
"You'll have to," I said. "Now, or shall we wait?"
"A vote?" suggested Teron. We voted to wait. Until there was no more time left.
The lander began to vibrate. The noise on the hull was like a buzz saw grinding.
We wouldn't have to wait long.