All of this means that Earth-size planemos may be numerous but practically unobservable unless they are relatively close to our solar system or in orbit around a larger object farther away. This is a pity, because they may be an important and diverse class of terrestrial planets. Perhaps one day, detection techniques and spaceflight technology will advance to the point where terrestrial interstellar planemos will become our testing grounds and our bases, our stepping stones to the stars. But how are we going to find them? And how are spacecraft going to avoid running into them? Any ideas?
Copyright (c) 2007 Kevin Walsh
* * * *
Further Reading:
Stevenson, D., 1999: “Life-sustaining planets in interstellar space?” Nature, Vol. 400, p 32.
Jayawardhana1, R. and V. Ivanov, 2006: “Discovery of a young planetary-mass binary.” Science, Vol. 313, pp. 1279-1281
Raymond, S. N., A. M. Mandell and S. Sigurdsson, 2006: “High-resolution simulation of the final assembly of Earth-like planets. I. Terrestrial accretion and dynamics.” Icarus, Vol. 183, pp. 265-282
* * * *
About the Author:
Kevin Walsh is an associate professor in the School of Earth Sciences, University of Melbourne. He has interests in climate change, climate variability, and planetary science.
[Back to Table of Contents]
Novelette: KUKULKAN by SARAH K. CASTLE
Illustration by Vincent Di Fate
* * * *
What people seldom fully grasp is that contact with aleins may involve things truly ... alien.
* * * *
"Our third winner is Pascual Teotalco. Mr. Teotalco is an American of Guatemalan descent working on a BS in astronomy at Vanderbilt. He is the first of his family to attend university. His intriguing proposal for the Fox Foundation's Message to the Stars Contest draws on his Mayan heritage.” Dr. Leinster's voice filled the auditorium at the Arecibo Radio Observatory.
Crossing the stage, Pascual squinted at the few dim figures seated in the audience. He hoped Dr. Giocacci, the Arecibo student internship coordinator, was out there. He suspected his proposal was chosen mainly to add cultural color to Foundation's pool of winners. Fine with him. He'd entered their contest mainly to win the free trip to Arecibo and to meet the internship selection committee in person.
"Good afternoon, I'm honored to be here. Thank you for taking time to listen to our ideas on how to hail extraterrestrials. I know you all have full research agendas studying things currently known to exist outside our solar system and would like to get back to work, so I'll be quick."
This drew some chuckles from the audience. Pascual smiled and began, determined to keep his promise to be quick. He'd practiced the presentation six times before making this trip, timing himself to finish in exactly fifteen minutes. Knowing the protocol and sticking to it were important to making a professional impression.
The message he sent into space today was nowhere near as important as the one he hoped to convey to the internship committee. He'd placed his future in their hands. If he wasn't good enough for the Arecibo internship, he would be a good Mayan boy and move back home to Florida. He'd get credentials to teach high school science in West Palm Beach and live in the Mayan refugee community he'd come from. He loved astronomy, but he owed it to his family to start making money as soon as possible after graduation.
If he was accepted to Arecibo for the summer, then he would apply to Berkeley's astronomy program and work toward a PhD. Such a prestigious internship would convince his parents he was good enough to make a living as an astronomer. Right now, he needed to convince this audience.
"The beauty of my message is its simplicity and the inclusion of a critical mathematical concept: zero."
He progressed to his first slide, a photograph of stones and short sticks arranged in groups on a wooden deck. “Since ancient times, Mayans used sticks and stones, or dots and lines, to express any integer from one to nineteen. One stone was equal to one unit, and one stick was equal to five units. They expressed and manipulated numbers in the exact same way that we do today, using a place-value number system."
Advancing the slide, the delicate spiral face of a seashell filled the screen. “My Mayan ancestors, and the Olmecs who came before them, recognized the computational utility of zero, which they denoted as a shell. They used it both as an empty place indicator in a string of other integers and as a number in itself, used to indicate the absence of value."
"This discovery was made in Central America more than a thousand years before the Arabic numbering system that we use today was developed and came into use in Europe. Europeans studying our ancient documents were surprised to learn that Mayans and their predecessors used the concept of zero, allowing them to count to, and perform mathematical operations on numbers reaching to billions."
Pascual advanced to a photograph of an ancient calendar round carved into a stone stele. “And count they did, they counted days, observed the sky, and developed accurate solar and ceremonial calendars. We continue to count today. Our Long Count is 5,129 years long. It defines the current cycle of creation. This cycle will end on December 8, 2012, just five years from now. A rumor is spreading that we Mayans believe the world will end on this day, but you shouldn't worry! It's just the beginning of a new cycle. Go home tonight, sacrifice a chicken, and you'll get through it just fine.” He wasn't joking, but he smiled at the audience to let them know it was okay to laugh.
"I proposed we send a message to the stars highlighting our understanding of zero. Just as the Europeans interpreted the knowledge of zero as a sign of higher-level mathematical thinking among the ancient Mayas, so might an alien culture be waiting for a similar signal from us. My message is simple and graphic. Not knowing how ET thinks or interprets radio waves, our message should be as simple as possible."
The next slide showed a string of dots and dashes in a line. The same sequence was arranged into a matrix in the center of the slide.
"The high and low frequency signals, I hope, will be interpreted as dashes and dots. When arranged in a prime factor matrix five places wide and twenty-three places tall, the frequencies arrange the dots within a field of dashes to form a diamond with an X drawn through it. This shape serves as a geometric visual break. It also has cultural significance to Mayan and Aztec people. The overlapping diamond and X pattern is frequently found in Mayan artwork and architecture. It represents the diamond pattern found on the backs of local rattlesnakes and symbolizes Kukulkan, known to the Aztecs as Quetzalcoatl, the feathered snake god who brought writing and mathematics to Mesoamerica."
"Below that, the symbols arrange to form an oval, which represents zero in many place-based numbering systems. At the bottom of the matrix, on successive lines, the length of the Long Count is written out to five places using the vigesimal, or base-twenty, place system used by the Maya. It will demonstrate our knowledge of zero and numerical place systems."
Pascual glanced at his watch and smiled. He'd spoken for fourteen minutes and thirty seconds.
His final slide showed the words “Thank you” in English and in his native Q'anjob'al. “In the three minutes this message is repeated, Mayans will speak to the stars after observing them for millennia. Thank you for this opportunity. Are there any questions, please?"
The dim auditorium was silent. Pascual looked over at his cowinners, who were still seated on the lit stage. The boy from Cornell squinted at him quizzically. His third grade classmates used to look at him that way when he amazed his teachers by quickly conducting long divisions in his head.
Dr. Leinster took the podium from Pascual. “Well, the Fox Foundation has certainly sent us a diverse selection of messages. Don't think I've ever seen sticks and stones on a slide in this auditorium before! Thanks for that Mr. Teotalco."
The small audience broke into a quick round of applause. Pascual's heart sank. They thought it stupid, maybe charming, but ultimately stupid. He sat next to the others as the applause wound down, but
one person continued after the others had quit. Pascual searched the room and saw a woman with curly hair seated toward the back.
"Bravo, Mr. Teotalco! Thank you for your interesting proposal.” Her voice filled the large room.
"Yes, well, all three winner's presentations have broadened our horizons today. Now we'll head over to the control room and send ‘em out.” Dr. Leinster gestured for the contest winners to follow him off stage.
As they filed from the room, the woman waited to walk out next to Pascual.
"Don't listen to him, he doesn't mean anything by it. He spends too much time with his data and not enough with people. Your idea is fresh, and your presentation was concise and interesting,” she whispered as they rubbed shoulders in the aisle.
"Thank you, Ms.?"
"Dr. Anna Giocacci. You will hear from me soon, Mr. Teotalco.” She smiled, shook his hand, and headed off down the hallway in the opposite direction.
Yes! Pascual pumped his fist for joy. He could make it as an astronomer! He watched Giocacci disappear around the corner at the end of the hall. He had to run to catch up with Dr. Leinster and the other contest winners.
In the control room, they stood among desks mounted with multiple computer monitors as the first message transmitted. Pascual's mind buzzed. The internship would strengthen his already solid application to Berkeley. He wanted a full research assistantship, based on academic merit alone, no minority-focused scholarship this time. It was now within his reach. The more he thought about it, though, his emotions scrambled. Graduate work would mean at least four years at Berkeley, away from his Q'anjob'al Mayan community and family in West Palm Beach. The four years at Vanderbilt already set him apart from his sisters and high school friends.
"Pascual, here goes your message.” Dr. Leinster said.
Pascual nodded at him. If he tried to speak, his voice would surely crack. At this moment, Papa was picking oranges in a Florida grove. Mama was probably hemming someone else's pants. He sat in the control room of the world's largest radio telescope, speaking to the universe in Q'anjob'al. It felt futile and a little frightening, like trying to tell Papa about supernovae or explaining his belief in traditional day-keeping and divination to a fellow astronomy student. He was moving farther into a hybrid world, and it was lonely.
* * * *
A Cheorka diplomat usually worked alone. But this mission was different in so many ways, the Universal Council decided to send a clutch. Their ship arrived in Earth orbit, shielded from detection by its plasmonic skin. The end of his preparation time rapidly approaching, Aranead again watched the five-thousand-year-old recordings of the Earth mammals made by the reconnaissance team. He'd been honored with the initial contact on this tragic planet and studied hard to do it justice. His three clutchmates watched recordings of Earth's more familiar creatures. They croaked softly together at the group sensorium on the opposite side of the ship's main nesting. They were pulling away from him already, and it hurt. Any one of them could have been chosen for the first contact, but his study, comparing mammalian husbandry techniques across cultures, put his name first on every Council member's tongue for this mission.
He couldn't help overhearing his siblings.
"They look like the Avidia of Alrai, in miniature.” Wa'akon said quietly.
Aranead turned and looked at their screen. It showed a black, feathered being perched on a rock next to an ocean. Its sinuous neck and long, sturdy beak did look Avidian.
"It watches the water so intently, but doesn't smell the fish! We can smell them on the recording, but it just stares.” Chika said, and the other two clucked in agreement.
"Look at its eyes! There's nothing but instinct, a vulnerable animal's primitive will to survive.” Deekor chirped.
The creature finally comprehended the smell and its meaning. It pulled its head back, curving the neck into a graceful S-shape. Its pupils dilated for the hunt, and it crouched to take off. It launched; the clutch squawked.
Aranead forced his attention back to his own sensorium. The hairless mammals on the screen had dressed themselves in feathers, apparently to imitate the Cheorka recon team. Aranead's skin ached at the thought of so many feathers plucked. The creature's monotone speech, made with rubbery lips, sounded blurry to him. They sounded and smelled like livestock, but they didn't act like them.
"The recon team did an excellent job.” Wa'akon approached behind him. “It's sobering to watch the archosaur tapes, to see what's left of them on this poor planet. Studying them will be instructive, but to spend so much time with these stumbling little creatures, interpreting their mumbles and growls, it must have been very difficult."
"It was, and will continue to be, difficult. It's time to face it. We can't ignore our responsibility any longer.” Aranead turned to face Wa'akon, annoyed. Wa'akon was second to hatch. If she hadn't spent those years fishing on Cancri, her experience might have equaled Aranead's, and she could have been chosen for this honor.
"Mammalian intelligence, I can't imagine it.” Wa'akon returned the aggressive gaze.
"We must imagine it, and we need to respect it as peer to our own. We should have stayed after the recon mission. The Earth creatures were clearly self-aware and took some teachings from the recon team. An archosaurid race at that developmental stage would have been fostered."
"They would have been fostered by a physically similar race. Who would foster mammals? The Universal Council debated this for over five thousand years, since the recon mission returned. Now the mammals call for us. We have no choice but to respond. We will invite them to Council, as we would any other race."
"It's going to be different. It's as if we killed the Avidia on their nursery planet, and the mice crawled from their dens and took over the world. It's as if the khulon..."
"That is what we did, broodmate. If you would have given our responsibility to the recon team then, perhaps you would pass it to me now?"
Aranead's hardened upper lip pulled back from his teeth and he used force of will to push it back down. Wa'akon was trying to help. If he passed this task to the second hatched, he would shame the lineage.
"You're worried about controlling your instincts, aren't you?” Wa'akon raised her feathered crest to a point.
"Of course I am."
"The instinct to feed?"
Aranead felt his crest start to fall and caught it. “Yes, that's it.” He hoped Wa'akon hadn't seen his disappointment. She obviously didn't want to discuss the other instinct Aranead would need to control.
"Practice, then. Deekor! Chika! Aranead will practice the Contact Ceremony for us!"
Aranead's skin prickled. They wouldn't talk to him about how this mission would be different, only how it would be the same. Fluffing his breast feathers, he took a deep breath. The ceremony would be his salvation, his guide. Practice would help. Adherence to ceremony brought the Cheorka through millions of years with their culture intact. It would get him through the next couple of days.
He began the song. The meaning of the whistles, buzzes, and burrs would be lost on any but Cheorka, but the dance could convey meaning. Tucking his wings close to his body, he placed each foot rhythmically, walking a straight line to the first corner. There, he extended his neck to the right, toward the ground, and nodded, warbling and miming feeding. He turned sixty degrees to the right and walked an equal length straight ahead. There, he stopped, facing left, and spread his arms, extending fingers from his wing's leading edges. The one sharpened talon on each hand poked forward twice as he shrieked and mimed defense. He hopped to spin one hundred twenty degrees to the right, and then repeated these two sequences twice to surround the imaginary nest.
He pictured the nest in his mind and tried to imbue each movement of his body with the care and teaching, defense and protection intended by each vertex of the dance. But when he imagined the nest full of mammals, it fell apart. He stamped his feet and turned toward his clutch, who were nodding their heads in time with the song.
"How
will they understand? They gestate their young inside their bodies, and then carry them along after they're born."
Wa'akon turned her head to one side. “We don't know that they will. What comes after the dance will be more important to their understanding. But until you see how they react, you must stick to the ceremony. They should at least recognize the pattern and its ritual aspect. For now, as when you are on Earth, you must follow and complete the dance."
Aranead nodded. This dance had inspired terror in beings across the universe over millions of years. The pebble-skinned Krokos of Centauri, the scaly Deenos of Cancri, the feathered Avidia of Alrai, all of them, and thousands more since, had submitted to the creed of the Cheorka and joined the Universal Council. The message, coming from the most feared predator in the universe, was very effective.
He would follow the prescribed ceremony. It had worked so many times before. Surely, something in it would help him on this battered planet.
Aranead danced with careful steps back from the final vertex of the pattern, to a place along the midline of one side. He snaked his head low, dropped his wings almost to the ground, and stalked straight to the center of the shape outlined in the first part of the dance. There, he mimed picking at the ground with his right hand and slashing with the left hand's single talon. He opened his mouth wide to show the full extent of Cheorka dentition, tossed the invisible morsel in, and bit down. Pick, slash, bite. Then he continued straight out of the nest and swung his wings forward, hands low and facing upward. Again, he imbued each gape of mouth and sweep of wing with their intended meanings of offering and acceptance.
Aranead could not imagine how creatures who carry their young for so long would interpret this last part, or how they would react when they learned its meaning. The ceremony, he thought. When all else fails, fall back on the ceremony. He was clearly on his own for what came after.
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