The Next Continent (53 page)

“Then what about the electro-neutral grid—ENG, is it? The fibers found just beneath the lunar surface. What were they trying to accomplish?”

“We don't know much about that either.”

“This is getting very hard to pin down. Let me just break in here and say what I think. If I'm wrong, interrupt me, all right?

A signal is sent from the moon's south pole. No space agency or military organization admits to having sent it. So it wasn't sent by Earth. But Sixth Continent and Liberty Island are right next door, and that's how it was discovered. Here's my point: if you're going to build a TV station on Earth, do you build it in the middle of the desert or on a ship in the middle of the ocean?”

“Well, that depends on the broadcast frequency and output. If the station uses the megahertz band or higher, and if there are relay stations—”

“That's not what I'm driving at. You build the station where your viewers are. In a city, right?”

“I suppose, yes.”

“Now, judging from where the signal was sent, it's as if someone had anticipated that humans would build something in that area. So wouldn't that mean we were meant to take notice?”

“I wouldn't know. I'm not the one who sent the signal.”

“But you're a scientist—don't you have an opinion?”

“Along with the rest of the scientific community, I'm just not in a position to say what the purpose of the transmission might be. Of course, I have my own personal opinion, or perhaps it's a hope—but I'm afraid I'd better not speculate.”

The anchor made a few more attempts to draw his guest out further before giving up. He closed the program with a look of indigestion. The media expected scientists to quickly determine at least the purpose of the signal, if not its meaning. After all, humans did not send radio signals without a reason. If someone credible would just stick their neck out and offer an opinion, the media could follow up with investigation and coverage—“alien signals” certainly weren't bad for ratings. But as things stood, all they had to go on was the barest of conjectures. After the initial reports, media coverage rapidly declined, and the interest of the general public declined with it.

Scientists of all kinds, however, were enthusiastically studying the signal. Radio astronomers jumped in, even though their specialty was natural emission sources, not artificial signals. Communications engineers, linguists, and SETI researchers were following their own lines of inquiry, but the exogeologists and electrical engineers had a head start over everyone. For seven years, they had been working with ENG samples brought back by Serpent, though without much success.

It had long been rumored that the fibers comprised some sort of machine fabricated from elements in the regolith. The reason this conjecture did not receive more open support was that no scientist had any idea of how such a machine could work. Only once had ENG shown any evidence of functionality: a sample held at JPL actually generated a small percentage of new fibers. This took place after a magnitude seven earthquake rocked California, with JPL at the approximate epicenter.

Attempts to image the fibers using electron or atomic force microscopes were equally unsuccessful. At low magnification, ENG showed a structure roughly similar to plant cells. But when magnification was raised to the nanometer level, the microscopes lost calibration. A research group in Canada demonstrated that ENG was absorbing the energy directed at it by the microscopes. The mechanism of energy storage was unknown, and no one had been successful in coaxing their sample to emit a signal.

Researchers at Liberty Island did determine that the way the fibers were intertwined could potentially contribute to signal emission and modulation. They went to work after the signal was discovered by Sohya and his crew. Careful radar mapping of ENG density beneath the floor of Eden Crater revealed thousands of rodlike aggregations of fibers about two and a half meters long. The Americans speculated that these structures could act as primitive dipole antennas. Their length was consistent with the signal's frequency. When an alternating current was passed through them, they emitted radio waves.

Sohya's team only managed to record forty seconds of the transmission before it ended. They first noticed the signal when it interfered with their transceivers. In fifteen minutes they had rigged a crude receiver and recorded part of the signal. It consisted of a long series of unmodulated pulses with only two amplitudes. Since the recording was just a fragment, it was no surprise that it could not be deciphered.

If ENG could be used to transmit signals, it could also receive them. Was the Eden Signal a response to another signal of some kind? Sixty-megahertz radio waves had never been detected outside the solar system. This frequency corresponded to one of the spectrum absorption lines of oxygen, which made Earth's atmosphere opaque to the signal. A few communications satellites operated close to that frequency, but none had receivers capable of detecting a signal that was a hundred billion times weaker than a terrestrial TV broadcast. No radio telescope in orbit was observing at frequencies anywhere near sixty megahertz.

Only one antenna caught the signal that had started it all—the SETI module Tae had sent to the moon. The five-minute transmission slept in the machine's memory, forgotten till prompted by a query from Earth.

Nevertheless, this incoming signal was just as unintelligible as its reply from Eden Crater. Opinion was not unanimous, but most SETI researchers were forced to conclude that whatever its meaning, it was not meant to be decoded. Otherwise it would have been accompanied by a key.

Somewhere in space, a signal had been sent, to which ENG had responded. The signals had been intended for sender and receiver alone. The rodlike structures beneath the surface would not make very efficient antennas. Assuming the goal was interplanetary communication, a conical or parabolic antenna would have been far more effective. Why multiple dipoles?

There could be only one reason: by modulating the phase of signals emitted by individual rods, the direction of transmission could be varied even with a fixed array, like phased-array radar installations, which were stationary and did not need to sweep the skies. Apparently ENG was not designed to aim its signal in one particular direction. Multiple dipoles were robust, flexible enough to transmit in any direction, and could be assembled with minimal resources.

Some proposed that ENG might be a life-form carried in the ice from comets, capable of communicating across the galaxy in response to intelligent signals. But this hypothesis was eventually rejected. ENG did seem to have the ability to grow, a purposeful structure, and a certain capacity to adapt to its environment. But no scientist could devise a model whereby any life-form could have extracted metallic elements from the regolith and assembled itself into such a structure. A seed would be required. Planting seeds meant intentionality. The entity that had planted the seed must be the source of the signal.

This is what the radio astronomer had hesitated to say on national television. To do so would have invited a barrage of questions. Why plant the seed in Eden Crater? Why not on Earth? Why send one signal and then go silent? Without answers, the conjecture—which for many scientists represented a hope—would simply have been ridiculed.

Sixth Continent was preoccupied with construction and could not spend time doing research. Liberty Island produced no further findings. Life on Earth went on as usual. People reacted just as they had to evidence of life in a meteorite from Mars discovered in Antarctica: it was interesting but not astonishing. After all, ENG was not trying to invade Earth. It was not made of pure gold. It didn't announce the coming of Armageddon.

But there were a curious few who were like people expectantly awaiting a letter. They at least felt a tremor of excitement. Now they were certain that a writer of letters existed, even if the message had not been addressed to humankind.

Liberty Island's scientists kept working to solve the puzzle. Ironically, while Sixth Continent had discovered ENG, they were in no position to follow up. This difference between the two bases was gradually turning into a source of conflict.

SELS MODULE, EARLY
morning, February 12. The interior was a maze of machinery, piping, and conduits, similar to a chemical plant. Sohya and the module supervisor were peering into the water electrolysis tank.

“See? Those electrodes are broken,” she said.

“You're right. Almost half of them are toast. That couldn't have happened during liftoff. They must be defective. Do we have replacements?”

“No. We weren't expecting to need them. We'll just have to wait for the next tug.”

Sohya checked his wearcom and frowned. The screen was blank. “Battery's dead. I've had this too many years. I left the charger back on Earth.”

“I've got one in my cabin. Want me to charge it for you?”

“Yeah, could you do that for me?”

The supervisor put Sohya's wearcom in her pocket and ran some calculations on her own unit. “At this rate, we'll be below nominal oxygen levels in two weeks.”

“If we use the SFOG candles, we'll need more of those from Earth too. What about the greenhouse? Can we squeeze some O2 out of that?”

“The spirulina culture? It doesn't generate much oxygen.”

A simple greenhouse had been rigged on the module roof using leftover construction materials. Too small to grow plants for food, it was being used to cultivate spirulina, a strongly photosynthetic bacteria. Cultivating plants to absorb CO
₂
and purify the air would eventually be more efficient than chemical methods.

“Use the heliostats to increase the solar energy to the greenhouse. That should give us more output.”

“That might be a good idea. I'll rerun the numbers.”

“The heliostats should be free.” Sohya used the communication pad on the wall to call the Control Center. While he waited for a response, the supervisor gave him the high sign. The spirulina would close the oxygen gap.

The answer from Control was not promising though. “Who's using them?” said Sohya. “Some kind of experiment? Liberty Island?”

“Oh no. I forgot about that.” The supervisor winced. “Remember last month we agreed to lease the heliostats?”

“No one told me about that. Anyway, it's a life-support issue. Control, connect me with Liberty. I'll talk to them directly.”

The monitor went dark for a moment before a woman's face came up. Sohya was astonished. “Carol, is that you?”

“Well, hello, Sohya. How's everything in your neck of the woods?” Caroline Cadbury put her trademark sunglasses on her forehead.

“What're you doing here?”

“What else? Working. We have far better control over our rovers from here than we do from JPL. The lack of signal lag lets us do so much more.”

“I'm glad you're here. Listen, we need our mirrors back.”

“Sohya, your system control supervisor notified me earlier about the electrodes. He was hoping we might have some spares. You've got a long wait till the next tug arrives.” She smiled—was that a hint of satisfaction? “It's not critical. You have at least three other options I can think of off the top of my head. I suggest you use one.”

“Those mirrors are ours!”

“Right now they're ours. You made a deal. If you want to renege, better let Washington know.”

“Carol!”

The screen went dark. After a short conversation with Control, Sohya hung up. “Damn it! Control is more interested in ENG research than they are in this base. They suggested we just pull some oxygen from the fuel vault. In fact, they invited me to go get the tanks myself.” He noticed Tae standing in the entrance to the compartment. “You're up early. It's not even four yet.”

“Jet lag. I was in Vancouver till just before liftoff. I'm sorry to bother you, but—”

“No, it's okay. I'm finished here.”

“Really? Good.” Tae smiled and came closer. “You were talking to Liberty Island just now, weren't you? What's going on?”

Sohya briefed her on his exchange with Cadbury. “NASA is keen to investigate ENG, but our permafrost harvesting is getting in the way, and things have been a little tense. They think the grid's two-kilometer radius is significant, that the samples on Earth are too small to replicate its behavior. They think there must be some kind of critical mass effect.”

“So why do they need our mirrors?”

“They haven't told us. Maybe they just want to slow us down. Without the heliostats, we lose a lot of flexibility. We could use some extra income, so somebody must have decided to lease the mirrors to generate additional—” He broke off and stared at her. “Was that you?”

“Hm? Oh, yes. Yes…that was me.” She glanced away, embarrassed. “But I wanted to hear what you had to say.”

The SELS supervisor picked up a tool kit and smiled nervously. “Well, I think I'm done here, so I'd better leave you two to carry on.”