Covenant

45

The remains Lucy found were similar to humans,” Rachel said. “You think that life on other planets is like life on Earth?”

Hassim Khan shook his head.

“That’s unlikely. Life on other planets will endure differing environments. If a planet orbiting another star was more massive than Earth, then its gravity would be correspondingly higher, resulting in species of a more muscular build to counter their increased weight on such a planet. That could match the physicality of the species Lucy found.”

“But it looked almost human to me,” Ethan said, “just a lot bigger. Surely that can’t be possible on an entirely different planet?”

“Evolution often follows certain paths,” Hassim explained. “There are facets of biological species that often appear as a result of natural selection, especially in predatory species. Limbs, eyes, ears, grasping hands and so on appear frequently in the fossil record. There is no reason to think that this would not occur on other planets too.”

Ethan sat in thought for a moment.

“Do you think that genetic material could be extracted from Lucy’s find?”

“Almost certainly.” Hassim nodded. “Researchers have successfully extracted intact blood cells from a Tyrannosaurus rex bone some sixty-five million years old. The remains that Lucy found were only seven thousand years old. I wouldn’t be surprised if they were able to recover organic material from it, maybe even intact DNA.”

“Which would confirm the idea of life forming on a universal theme,” Ethan guessed.

Hassim smiled.

“The origin of life among the stars as a universal and not a local event,” Hassim agreed. “It’s known as panspermia.”

“You mean that we didn’t evolve on Earth?” Rachel stammered.

“Oh, we evolved here all right,” Hassim corrected. “But the very things we are made of did not, and that may include life in all of its self-replicating glory. It has been known for some time that when giant stars die in supernova explosions, the material they release in the cooling conditions contain carbon grains, and that particles of other chemical elements attach themselves to the tiny grains and react enthusiastically with each other. These carbon grains were given a name: stardust.”

“Grains?” Ethan asked. “Like sand?”

“Much smaller,” Hassim said. “Spectroscopic studies of these star-remnant molecular clouds have found there the presence of methanimine, formaldehyde, formic acid, amine groups, and long-chain hydrocarbons caught within their veils. These are the building blocks of life: methanimine is an ingredient in amino acids; formic acid is the chemical that insects use as venom and is also the stinging ingredient in nettles. Both are polyatomic organic molecules that combine to form the amino acid glycine, which has since been seen in molecular clouds in deep space and found in comets by NASA in 2009, and amino acids are one step away from life itself.”

“And that’s without planets forming?” Rachel asked.

“Yes,” Hassim said. “Ultraviolet radiation bathes the clouds, heat from other nearby stars warms them, and all manner of chemical reactions occur. Frozen water, methanol, and ammonia rapidly form around the grains as the heat from the supernova fades. Trapped within these tiny cores the elements react and produce various polyatomic molecules. Experiments carried out in 2001 at NASA’s Ames Research Center confirmed these processes, when silicate grains covered in this kind of material were chilled to the temperature of deep space and suspended in ultraviolet light. When the organic compounds produced were immersed in water, membranous cell structures appeared spontaneously, as they may well have done on the young Earth: life, without supernatural intervention. All life on Earth is based on cells such as these, biological material encased in a membrane.”

“It all fits together,” Ethan said, genuinely amazed.

“That’s what science does. In 2002,” Hassim went on without missing a beat, “further experiments conducted with water, methanol, ammonia, and hydrogen cyanide found in molecular clouds discovered that three amino acids called glycine, serine, and alanine arose spontaneously within the containers. In another similar experiment, no less than sixteen amino acids and other organic compounds were produced under the conditions that exist between the stars using nothing more than the ingredients of molecular clouds. The proteins of all living things on Earth are composed of combinations of twenty amino acids.”

Ethan grasped where Hassim was going just before Rachel did.

“All life might be very similar in a fundamental way,” he said.

“Yes,” Hassim agreed, and tapped his own chest. “The chemical reactions that support metabolism in all of our bodies involve just eleven small carbon molecules such as acetic and citric acids. These eleven molecules would have been sufficient to produce chemical reactions that led to the development of biomolecules such as amino acids, lipids, sugars, and eventually early genetic molecules like RNA on Earth. Metabolism came first, the fuel for life, before cells or replication or anything else. Life then followed as a natural result of chemical metabolism. If it happened here on Earth, then it could happen anywhere on suitable planets harboring liquid water, and life might follow a similar path of evolutionary development that leads eventually to intelligence.”

Rachel caught on quickly.

“And if an intelligent species evolved on a planet reasonably close by, and was only ten thousand years more advanced than us …”

“Even a thousand years more advanced might do it,” Hassim said. “In two hundred years mankind has gone from wooden sailing ships and witchcraft to landing on the moon and nuclear power. Think what we could be like in another thousand years.”

“It would look like magic,” Ethan said, remembering Arthur C. Clarke’s Third Law. “Or God. But could they be that much more advanced than us?”

“The universe has been producing stars for over thirteen billion years,” Hassim explained, “and the elements required for life have been in place within galaxies for at least eight billion years. By our planet’s timeline of evolution, it’s quite possible that advanced, intelligent life has existed in our universe for the past four billion years or so. The technology of such civilizations could be advanced on a scale completely unimaginable to us.”

“If so,” Ethan challenged, “then why would they bother with us at all?”

“We can only speculate,” Hassim admitted, “but such civilizations may well have been forced to travel through space as their parent stars aged and became unstable: the window in which our own Earth can support complex life is surprisingly short in cosmological terms, ending as the sun grows hotter and Earth is no longer able to harbor liquid water. However, although life may be common in the universe, intelligent life will be much rarer, and if you were an advanced race traveling the stars and found early humans struggling to survive after a climatic disaster, wouldn’t you be tempted to stop and help them or at least investigate?”

Rachel stood up, pacing again as she struggled with the consequences of her newfound knowledge.

“But if this actually happened, surely our ancestors with their newly acquired skills might have recorded it better, in more detail?”

“Perhaps they did,” Hassim said. “But we haven’t learned to recognize the signs for what they are yet.”

“How do you mean?” Ethan asked.

“Imagine,” Hassim suggested, “that you’re living in ancient Egypt, before the pyramids or technology, and down from the skies come beings that reveal great knowledge to you and then vanish again. As you struggle to capitalize upon this new knowledge, would you not be tempted to beg them for help, to make contact again?”

“I guess so,” Ethan agreed.

“And how would you do that?” Hassim asked.

“I’d make a sign,” Ethan said cautiously, “in the ground or something.” Then he got it. “A big sign, big enough to see from the air.”

“Exactly,” Hassimm nodded. “You’d create megastructures, hoping that your mysterious flying benefactors would see them and return.”

Rachel seemed bemused.

“You’re talking about the pyramids, aren’t you?”

“Not just the pyramids,” Hassim replied. “Almost every major ancient megastructure, and I can prove it too. Have either of you heard of something called a cargo cult?”

Rachel was about to answer, but Mahmoud got up from the crate upon which he had been sitting and looked at her.

“Whatever your daughter was dabbling in, it is better left alone. There are some things we weren’t meant to see,” he warned before looking at Yossaf. “Time to check the tunnels.”

Ethan watched as the two Palestinians went in opposite directions.

“Why would MACE abduct Lucy when they could just have taken the remains and left her there?” he asked Hassim.

“The reason for that, my friend,” Hassim said, “is almost too horrific to speak of.”