David Brin - Existence

“Neat trick with the sail,” Paul commented. “Tuck it away, when it’s not needed for propulsion or energy collection, so it won’t snag interstellar particles. With bi-memory materials, it could expand or contract with very little effort. I bet they use it later to slow down.”

Bin now grasped how the worldstone must have come across the incredible gulf between stars-a method sure to provoke feelings of kinship from this colony of wealthy yachting enthusiasts. At the same time, he wondered, What would ancient peoples, in China or India, have made of these images?

They would have thought in terms of gods and monsters.

How easy it would be, to chuckle over such naïveté. But, in fact, could anyone guarantee that modern humanity was advanced enough to understand, even now? In ways that mattered most?

Meanwhile, Scholar Yang’s narration continued.

“Slow time passed while the galaxy turned,

A new star loomed-its light, a cushion.”

The pellet turned around and redeployed its sail, which now took a gentler, braking push from a brightening light source ahead. Our sun, Bin realized. It had to be.

“Knew it!” the islander exulted. “Of course there’s no laser at this end. So sunshine alone won’t be enough.”

As the star ahead grew from a pinpoint into a tiny, visible disc, a new object abruptly loomed in front of the worldstone-a great, banded sphere, replete with tier after tier of whirling, multicolored storms.

“Chosen beforehand-a giant ball waited,

Ready to catch… pull… assist…”

Yang Shenxiu’s translation stumbled as, even with computer aissistance, he could only offer guesses. Well, after all, Courier had a limited useful human vocabulary. Ancient Indus and Chinese people knew very little about astronomy, planetary navigation and all that.

Just like me, Bin thought as the striped, cloudy ball approached rapidly.

“A gravity swing past Jupiter,” Anna murmured in apparent admiration. “Like threading a microscopic needle across centuries and light-years. They had to time it perfectly.”

The mighty gas planet swerved by, unnervingly fast, and the pellet, its sail billowed open, then plunged past the sun in a hairpin swerve before veering into black space. Far… far… until it paused at the end of a towering arc… then plummeted inward again, approaching the star from a different angle, filling the sail once more with torrents of light.

Paul interjected. “But it would still have loads of excess velocity. This needle must have been threaded many times, offering multiple swings past other planets, as well as Jupiter and the sun, again and again.”

His appraisal was borne out, as the broiling solar sphere darted by, making Bin’s eyes water. Just after nearest passage, the sail furled back into its container… and soon a smaller ball swung past, so close that Bin felt as if he were passing through the topmost of its churning, yellow clouds, while a brief, glowing aura surrounded the image.

“Atmospheric braking through the atmosphere of Venus. Dang! They’d need orbital figures down to ten decimals, in order to plan this from so far away, so long in advance.”

Then, another sudden veer and gyre past Jupiter…

“Yes, though it could make small, real-time adjustments, between encounters, by tacking with the sail,” Anna replied. “Still they wouldn’t arrange it in such detail without a destination in mind.” She made her own rapid finger movements. “They had to know about Earth already. From instruments, like our LifeSeeker Telescope… only far more advanced. They’d know it had an oxygen atmosphere, life, nonequilibrium methane, possibly chlorophyll. Even so-”

Without shifting his transfixed gaze, Bin had to shake his head. There was no way that ancient peoples could have made anything of this, even if Courier showed them all the same images and told them about these worlds, named after their gods-or the other way around. Bin’s head seemed to spin, nauseated, as the whirling, planetary dance went through several further encounters-more dizzying, gut-wrenching pirouettes-until the sense of pell-mell speed finally diminished. The pace grew sedate-if no less urgent. Then another dot approached, slowly, gracefully. Bin guessed which planet from its greenish-blue glitter.

“It must have intended to fine-tune its approach to Earth,” Paul commented, “by gradually tacking on sunlight till entering a high, safe orbit, perhaps at a Lagrange point. Then it would spend some time-centuries-evaluating the situation. Maybe use the sail as a telescope mirror, to gather light and make detailed observations from a secure distance. Then wait.”

“Wait… for what?” Anna was doubtful. “For the planet to produce space travelers? But, the temporal coincidence is incredible! To launch this thing, timed so it arrived only a few thousand years before we made it into space? How could they have known?”

Bin marveled how these skilled people grasped so much, so quickly. Even allowing for all of their fancy tools and aids. It was a privilege, just to be in such company.

Paul pressed his disagreement. “Anyway, how do we know there was anything special about the time they chose? Maybe these stone-things have been arriving at a steady rate, all across the last billion years, filling the solar system by now! We never surveyed the asteroid belt for objects anywhere near this small. That astronaut only happened to snag one that drifted into visible reach-”

“It’s still an appalling coincidence,” Anna persisted. “There has to be-”

“Comrades, please,” Professor Yang Shenxiu urged, raising his eyes briefly from his own work station. “Something is happening.”

The glitter of Earth had begun resolving itself into a dot, and then a ball, flecked with clouds and glinting seas. Only now, the storytelling image turned and zoomed in upon the star-traveling pellet. Once again, the little box at its front end opened, the sail re-emerging.

“At long last, the goal lay in sight,

Now to approach gently and find a perch,

To focus, study, and appraise,

Then to sleep again and wait.

Until a time of claiming,

When allures are certain. Ready…”

Only, this time, something went wrong. As the sail came out of its box, amid a glitter of sharp reflections, several of the lines abruptly snapped! One corner of the vast, luminous sheet dimpled inward. More lines crossed each other the wrong way. Bin blinked, feeling his gut clench as the sail rapidly fouled and collapsed, its slender cables knotted, spoiled.

“Evidently, something went badly wrong at the last minute,” Paul commented, unnecessarily.

Bin found he could barely breathe from tension, watching a drama that had unfolded many millennia ago. He felt sympathy for the worldstone. To have traveled so far, and come so near success, only for all plans to unravel. Yang Shenxiu recited ideograms conveying Courier’s sense of tragedy and dashed hope.

“Failure! Luck evades us,

While this globe reaches out,

To cast my fate.”

Bin glanced at the scholar, who seemed far away in time and space, his eyes glittering with soft laser reflections cast by his helper apparatus. Of course, the alien entity’s florid vocabulary must have come from its long era spent with early humans, many centuries ago, in more poetical days.

“Will Earth embrace me

– in a fiery clutch?

Or will she fling me outward,

Tumbling forever-

– in cold and empty space?”

Unable to maneuver even a little, the pellet let go of its uselessly clotted sail as the planet loomed close, swinging by, once… twice… three times… and several more… From Paul’s commentary, it seemed that some kind of safety margin was eroding with each orbital passage. Doom drew closer.