"Garvin, you're out first. We'll stay behind, but Dan will be in his suit, ready to come out and help you if need be.
Garvin nodded.
"I'm asking you to take the lead because you're stronger than any of us, and it's almost two G's out there. That's twice your weight, plus twice the weight of the space suit, plus your tools. Fortunately these new suites are pretty light, but the helmet is still the heaviest part, and that's on top. If you fall on your back, you might not be able to get up, so please be careful. Take it slow, and when you're not walking, it's probably best if you kneel or sit."
"I understand."
"We're still on open mike, for the benefit of Earth. And your head-cam will be included in the downlink telemetry, so we will see, and Houston will see, what you are seeing."
"Fair enough."
An hour later, after the leak checks were complete, Garvin descended the ladder, very slowly. When he set foot on the probe he wanted to say something profound, something like "One small step for man", something commensurate with first contact, but no words came. He didn't know they would be landing on the probe, and he certainly didn't expect to be the first out. This was the Captain's honor, wasn't it? But nobody expected two G's of unrelenting force either. So he simply relayed his observations.
"I'm standing on the probe, on the red annulus, which is about 10 yards wide." His binocular estimate of distance was sure to be more accurate than the information one could glean through cameras. This became clear with the first Martian probes some 15,000 years ago. Even though they were outfitted with stereo cameras, inches would sometimes look like feet, and vice versa. There is just no substitute for human eyes, or the human brain. He panned to the left. "You can see the yellow stripe, then the blue stripe, and then the metallic gray of the hull. To my right," he turned his head the other way, "is the center of the bull's eye, which is painted white, with the portal in the middle." He slid his right foot ahead and back. "The surface isn't slippery at all. There's plenty of traction for my boots, and I think I can walk around safely. I don't know if the material started out this way, or if it has been roughed up by interstellar dust. Still, the colors look shiny and new. That must be some pretty amazing paint." He walked towards a streak of gray that cut across the red stripe. "A large space pebble carved this path along the side of the probe. This will allow me to analyze the metal underneath, without worrying about the paint on top." He got down on his knees, as Nancy had directed, and spread his instruments out in front of him. The light from his helmet shown directly into the crack, illuminating the gray alloy beneath. It took several minutes to align the spectrometer and take a reading. "Titanium, molybdenum, carbon, osmium, iron, and 1% trace elements. I'll patch the output into the telemetry."
"What do you make of that?" Nancy asked.
"I'm not an expert in metallurgy, but this strikes me as very unusual. I've never seen an alloy like this. And I don't know where they got all their molybdenum from. There's more molybdenum here than we have in all the mines on Earth. And Captain, this metal is dense, almost 50 times as heavy as water, and 23 times as hard as diamond." He placed other instruments against the exposed metal. "Electrical conductivity is high, though not as high as a pure metal such as iron or copper. But it's high enough. An electro magnetic field isn't going to get in or out." Another instrument sent pulses of sound waves into the shell and waited for echos. "The speed of sound is about Mach 17, which isn't surprising, given the high density." Two minutes passed in silence while Garvin made more readings. "Based on the echos through the hull, this shell is about 10 feet thick. I don't know what's inside, but we couldn't even begin to build a shell like this, thousands of square miles of a super strong alloy forming a perfect sphere. That's all I can tell from here. I can cut out a small piece for further analysis, but I'll have to use the laser. We don't have anything strong enough, or sharp enough, to break off a piece."
"Hold on a second, while I think." Eager to take a break, Garvin sat down on the hard surface while Nancy continued. "I'm sure the melting point will be higher than anything we have on board. If you create a puddle of molten metal, what are we going to do with it? We can't scoop any of it out, because we don't have a spoon that can stand the heat. If you see what I mean."
"Besides," Dan injected, "some metals are not the same after they have melted and recrystalized."
"Yes, " agreed Garvin, "some metals acquire their properties by being cooled under very specific conditions, such as pressure, zero gravity, or rapid cooling. But it's hard to believe this entire shell was subject to extraordinary conditions. As a first guess, I'd say this mix of elements will produce the same metal when melted and cooled."
"I don't know," doubted Nancy, "we've never seen anything like it, and we've made a lot of alloys on Earth. They might have built the entire shell, in pieces, in zero gravity, then put the pieces together around the black hole. I wouldn't underestimate the Arcots."
"Ok. But Nancy, I've cut out solid pieces of rock before, using this laser. You melt a ring around it, then melt the area underneath, and that frees up a sample that has never been melted, though it is often quite hot."
"You're not working in zero gravity, or on a hillside. The section of metal that you have freed will simply float, or sink, in the molten metal that surrounds it. How do you propose to fish it out?"
"Yeah. That is a problem."
"Tell you what - why don't you melt a small area of metal, just a fraction of an inch across, so we can see what the melting point is."
"Aye aye, Captain." The laser poured energy into a tiny spot on the surface, and the dense, conductive metal drained the energy away almost as fast. It took two minutes for the spot to become red hot, then another ten minutes to get white hot. Garvin lowered his shade and continued to apply the beam. Twelve minutes later the surface finally succumbed. "That's it - 9,598 degrees. Captain," he often called her Captain when they were on official business, "you could almost build a boat out of this stuff and float on the surface of the sun. It would stand up to the lower temperatures of a sun spot in any case. Imagine sailing about in a sun spot. Course, when the sun spot turned into a solar flare, you'd be toast."
"I'm afraid you'd be toast anyways," chuckled Dan, "but hey, your boat would survive."
"Yeah." The spot was cooling rapidly, from white, to orange, to red. Garvin reapplied his instruments. "It's not the same metal any more. I don't know why, but it's not as dense, and not as strong." Indeed, the area seemed to puff up above the surface, forming a small hill. "Apparently you're right - they did something more than throw elements together to make this metal."
"All right, I'm not surprised. Listen, you've been out there two hours, your heart rate is up, and you're breathing is labored. I want you to walk over to the portal, do a visual inspection, and then come back inside."
"Good idea." Garvin gathered up all his instruments, placed them in his pack, and slowly, very slowly, stood up. He walked across the red stripe, into the white circle, and over to the portal. "Can you see it?"
"Yes." said Nancy, looking into the display screen that was linked to Garvin's head-cam. A round glass window revealed only darkness inside.
Garvin turned on his floodlight, but most of it was reflected by the glass. "I think I see a ladder inside, descending through the shell and down to a small room below. That's all I can make out. I don't think you're going to get that detail through the camera."
"You're right. Now - if you could pan back over to the right, next to the window." Garvin obeyed, and the control panel slid into view. There were only four buttons, recessed into the shell. Each had one word written next to it. "Can you read that?"
"Yes." said Dan. "From top to bottom, the words are: Pressurize, Depressurize, Open, Close."
"That's it?" asked Nancy in disbelief. "No number pad, no secret code, no combination lock? Just push open, and the portal opens?"
"So it would seem. We already decided the Arcots didn't expect us to come and walk on the surface of their probe. Either they are very trusting, or they are overconfident."
"Or it's a trap." suggested Garvin as he made his way back to the ship.
"They have so much power, they hardly need to set a trap." Nancy watched Garvin climb the ladder at the base of the ship. "They could kill us easily, if they knew we were here. I think Dan is right; they aren't expecting us."
Garvin entered the air lock, retracted the ladder, closed the door, pressurized his compartment, and slowly climbed out of his suit, with some much appreciated help from Dan. After an hour's rest they reconvened in the kitchen. Nancy spoke while Dan placed their dinners in the microwave.
"I wanted to talk to you about this before I present the idea to NASA. Let me start with a question. Why do the Arcots need that communications dish on the back of the probe?"
"You said it yourself," replied Garvin, "a continuous telemetry downlink."
"Yes, but why is the radio link even necessary?"
"I see." said Dan. "The worm hole inside can communicate efficiently and instantaneously. Just point a transmitter at the black hole and receive the telemetry on the other side. That's what they claimed."
"Yes, that's what they claim, but the radio dish says otherwise." She placed her prefabricated dinner in front of her, noodles and beef tips. "This is one deception too many, the straw that broke the camel's back."
"What do you suggest?" asked Dan.
"I want to destroy the transmitter."
Garvin froze, his fork in mid air. "Our first contact from another race, and you want to begin by vandalizing their probe!"
"We can tell them that it simply failed - a malfunction. Since all telemetry has stopped, they'll have to take our word for it. They'll never know."
"You want to deliberately damage their interstellar craft?"
"Yes, but I'm asking for your opinion."
"Well I think you know mine. That's like shooting at the Indians when you first meet them. Hardly a way to begin a relationship. And these aren't Indians with bows and arrows, these are people who are a million years ahead of us, technologically. You may as well poke a tiger in the side with a fork."
"Nancy's right." stated Dan. "Destroy it. The minute we open the portal the probe will signal that event to its home world. The Arcots will know we are going inside. And if anything happens to the probe after that, they'll know we caused it. We need to sever the link now, before we do anything else. Keep them in the dark."
"Look, they already know we're here." Garvin growled. "They saw us on radar."
"Just a blip," argued Dan, "and it could have been an asteroid. Besides, they destroyed us with their nuclear weapon. After all, we didn't come around again, did we? The arcots aren't expecting us, and if we destroy the transmitter now, they'll never know we're here. They'll just think the transmitter failed."
Yeah, after 8,000 years of reliable performance, they'll figure the transmitter failed, just two years and seven months before arriving at Earth. I don't think they're going to buy it."
"Well it's the best we can do. It buys us some time, and it gives us the most options. We can poke around in secret, and that's really what we need to do right now."
"I just think that's a terrible way to welcome a new race to our solar system. It may entail a little more risk, but I think we need to take the moral high ground."
"Ok gentlemen," Nancy interrupted, "we may have to disagree for now. I'd like all of us to sleep on it, and tomorrow morning we'll go over it again. I'd feel better if the decision were unanimous, but remember, I am the captain, and the buck stops here." She placed her tray in the garbage and her silverware in the dishwasher. "It's been a long day; how about a movie, and then a good night's sleep."
"I get to pick the movie this time - something within the past century for a change." Garvin knew Dan was just teasing, and he would have smiled, but he was still angry at the thought of damaging the probe on a whim. There were so many things they didn't know about the Arcots. With so many variables, Nancy had no right to assume the worst. "And to think," he mumbled to himself, "I was actually attracted to her."
They settled into soft couches and recliners as the movie began. It was hard getting use to 2 G's. Everything was work - walking across the room was work. Leaning back in a soft chair was a real pleasure.
"I really need a shower tonight." thought Nancy. "This is the first time we've had gravity in over a week. but I better use the shower chair, if I can find it. Standing on a hard slippery floor in 2 G's isn't wise. It would be sad to stare down the Arcots, and survive a nuclear blast, only to slip and fall in the bathroom." She closed her eyes for a moment, listening to the movie, then resumed her mental conversation. "Shit, the shower chair is in supply room 3. I'm not going to don a space suit just for that. I'll have to find something else to sit on."
The movie was interrupted by a synthesized voice. "Attention crew, incoming message, priority 1, all present." Nancy sat up suddenly, and felt a little dizzy as the blood fell away from her head. Priority 1 was an emergency. Houston wanted their attention, and right now! Garvin paused the movie and played the message on the big screen. Julie appeared on the screen, her long red hair pulled back and her green eyes clouded with tears. Her voice broke a couple of times as she talked.
"We've been through this a dozen times, and there's no mistake. Let me start at the beginning. We've been tracking your telemetry, and we can infer the speed of your ship from the doppler shift in the carrier signal. This is standard procedure around here. As you swung around the probe, we were able to measure its mass precisely."
Nancy was stunned. "Why didn't we think of that?" They had the same software on board. They could have run the same calculations; they were simply too preoccupied with the probe. "That's the first thing you'd want to know, isn't it? The mass?"
"Shhhh." said Dan. Julie was speaking again.
"The mass is about 3% higher than we expected. Here is the projected path, using the new mass."
Julie disappeared behind the now familiar animation. A red line streaked towards Jupiter, bent in response to its gravity, received a small nudge from Ganymede, sailed on past the orbit of Mars, and ran smack into Earth.
Julie returned, and said nothing for several minutes, as if there was nothing else to say. The crew of Explorer 29 returned her silence. Finally Julie spoke again, wiping a tear from her eye.
"We don't know if this is intentional, or a malfunction. Either way the end result is the same. There are four possible outcomes, and they aren't pretty. I'll spare you the animations. The outcome depends on the form of matter inside the probe. Believe it or not, a black hole produces the best possible scenario. The probe slams into the Pacific Ocean and creates the largest tsunami in human history. The shell smashes into the ocean floor and the black hole drills through the Earth and out the other side, destroying most of northern Africa as it exits. Then the black hole sails on, barely slowed down by the Earth at all. It races out of our solar system and is not seen again. After a few weeks the earthquakes subside, and the Earth returns to normal. Human beings would survive, and our civilization might survive, if we're careful. We do have two and a half years to prepare.
Once again Julie was silent. Garvin took advantage of the moment. "Nancy, I think we should destroy the transmitter right away. You were right, and I'm sorry I doubted your judgment."
"Your position was reasonable, given the data you had to work with. I asked for your opinion, and I'm glad you stood your ground."
"Yes, but that's all..."
Julie found her voice once again. If most of the mass consists of neutron star material, the result is pretty much the same, although the mini neutron star will grab approximately 2% of the Earth's core along the way and carry it off as it leaves the solar system. Earthquakes will be global in scope as the planet regains its equilibrium."
She paused to look at her notes. "A white dwarf is probably the worst. It will burrow through the Earth, but it is much wider than a neutron star of the same mass, so it will slow down considerably. When it bursts through Africa it won't have enough speed to escape Earth's gravity. It will fly out into space, then fall back down to Earth some four hours later, after we have turned 60 degrees. This gives it a chance to drill a fresh hole through the Earth, at a new location. This continues several times, until there is no longer sufficient energy to break out of the ground. Even then, the white dwarf swings back and forth, back and forth, turning the Earth into swiss cheese. Iron collects on its surface and is crushed under the intense gravity. Within a few months, the entire planet collapses onto the surface, making one large, superheated, uninhabitable white dwarf. There is no life, and life can never return."
Julie paused and cleared her throat. "The last scenario is the most likely, but it's not good either. Assume the probe is filled with regular matter. It would have to be a dense metal, denser than anything we have here on Earth, but let's say such a metal exists. The collision creates a huge impact crater, and fills the air with superheated material. The oceans boil into steam under the intense heat. Nothing survives. However, if the Martian colony can hold out for a few thousand years, they might be able to return to Earth and find it habitable once again. The problem here is the colony's dependence on us. They can grow their own food, and recycle their air and water, but technology is another matter. There is no clean room on Mars, and no way to manufacture integrated circuits. One by one the computer chips will fail, and when the computers fail, the colony can't survive. Based on industry specs, and the law of large numbers, the colony would collapse in 350 years. We are currently packing our transports with as many chips and spare parts as they will hold. We'll fill their supply rooms from floor to ceiling. Hopefully they can hang on for a few thousand years. We're also sending DNA for every species we can get our hands on, since they may have to repopulate the biosphere."
Garvin was still stunned. "What are we going to do?"
"I don't know." answered Nancy.
Julie took a drink of water and put the glass down on the desk. "NASA is scrambling to get Explorer 37 and Explorer 42 ready for launch. They were pretty much ready to go, but we're trying to outfit them with weapons and equipment, just like we did for you. If we can get them off the launch pad in 30 days, they will be able to intercept the probe before it reaches Jupiter. But this is a fall-back plan. You are our first line of defense. I can't tell you exactly what to do. We don't know. Somehow, the rock that the Arcots have thrown at us has to be destroyed or diverted. You need to go inside to get more information. I hope you can find a way in. Oh - and one more thing. We suggest you disable their transmitter, so the Arcots don't know what we're doing. If anything, we want them to think they succeeded. The last thing we need is a repeat performance in 15,000 years. Since there may be several transmitters working in a redundant array, your best bet is to destroy the dish. There's only one of those, and when it's broken, you'll see that it's broken. The probe can continue to transmit, but the waves will spread thin throughout space, and will not be directed towards Arcot. A hundred kiloton bomb should do the trick. Don't use anything larger, because you don't want to disable the probe itself. We may need to commandeer its engines. We don't have the technology to move that much mass ourselves. Whatever you do, keep an open downlink to us, so we can see and learn. If you aren't successful, the next two ships will need all the information they can get. If you find a way inside, leave a relay station at the entrance, so we can continue to watch your activities and offer suggestions. Finally, let me close by saying you have the final authority. It may not be practical for you to ask permission and wait 26 hours for an answer. You're out there because we trust you; we trust your judgment. If you have an idea, a plan, carry it out. We'll support you in any way we can."
Julie disappeared, leaving a blank screen. Nobody felt like resuming the movie. Nancy broke the silence. "This is going to be difficult, but I suggest we get some sleep. When we enter the probe, we'll need our wits about us. We have to think clearly, and we have to work together. Nobody can do that without sleep. Nobody. I'm going to acknowledge the message and go to bed. If you simply can't sleep, you might want to set up the nuclear missile. Use the parameters that Julie suggested. That makes sense to me. And follow up with a reconnaissance satellite to confirm the strike."
"Yes Captain."
Nancy sent a short reply back to Houston, acknowledging the message. "We'll destroy the dish tomorrow, and after that, I don't know. For now, we need to sleep." She left her two friends in the lounge, borrowed a plastic chair from the kitchen, took a shower, and went to bed. The others followed her lead, but sleep did not come easily for any of them. They tossed and turned in their beds, visualizing the end of humanity, perhaps the end of all life in their solar system. The scope of evil was as immense as the technology that was used in its implementation. Nancy remembered when she was a teen-ager, reading about the Holocaust. An entire nation, its industry, its military, its people, all working (directly or indirectly) towards the single minded goal of genocide. It was unbelievable, and she had some sympathy for those who refused to believe it, despite the historical evidence. It boggled the mind. But that was nothing compared to this. The Arcots possessed technology beyond anything imaginable, yet they focused their collective effort, the combined science and engineering of their entire race, on the destruction of nascent civilizations throughout the Milkyway. "When you see that signal in the sky," Nancy advised, talking to some other inhabited planet on the cusp of technology, "ignore it. Don't tell the Arcots you're here. If you're lucky, they'll never find out." Eventually she fell asleep, her thoughts and dreams haunted by visions of fireballs slicing through the Earth's core and reducing the planet to a compact cinder.