Eight light years away, a star has died, creating a supernova event that showers Earth in deadly levels of radiation. Within a year, everyone over the age of thirteen will die.
And so the countdown begins. Parents apprentice their children and try to pass on the knowledge they’ll need to keep the world running.
But the last generation may not want to carry the legacy of their parents’ world. And though they imagine a better, brighter world, they may bring about a future so dark humanity won’t survive.
From Cixin Liu, the Hugo Award-winning author of The Three Body Problem, comes a new science fiction masterpiece in Supernova Era. Translated for the first time into English by Joel Martinsen, Supernova Era is available October 22nd from Tor Books.
1
THE DEAD STAR
THE END
In the space within a ten-light-year radius of Earth, astronomers discovered eleven stars: the triple-star system formed from Proxima Centauri, Alpha Centauri A, and Alpha Centauri B; two binary-star systems, Sirius A and Sirius B, and Luyten 726-8 A and Luyten 726-8 B; and four single stars, Barnard’s Star, Wolf 359, Lalande 21185, and Ross 154. Astronomers have not ruled out the possibility that other stars, either especially dim or obscured by interstellar dust, are waiting to be detected.
Astronomers had noticed in this area the presence of a large amount of cosmic dust, like a dark cloud floating in the black night of space. When UV sensors on a satellite were trained on this distant cloud, a peak of 216 mm was found on the absorption spectrum, suggesting that the cloud was likely formed from carbon microparticles; the cloud’s reflectivity suggested that these particles were covered in a thin layer of ice. The particles were in the 2–200 nm range, roughly the same as the wavelength of visible light, rendering it opaque.
It was this cloud that blocked a star eight light-years from Earth. Twenty-three times the diameter of the sun and sixty-seven times its mass, the star was no longer main sequence but was in the final phase of its long evolution, its waning years. We’ll call it the Dead Star.
Even if it had a memory, the Dead Star would not remember its childhood. It was born fifty million years ago out of a mother nebula. Atomic motion and radiation from the galactic center disrupted the stillness of the nebula, whose particles congealed around a center under gravitational attraction. This stately dust storm endured for two million years, while in its center, hydrogen atoms began to fuse into helium. The Dead Star was born out of this atomic furnace.
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Supernova Era
After a dramatic childhood and rocky adolescence, fusion energy arrested the collapse of the stellar crust, and the Dead Star entered a lengthy middle age, an evolution that took place over hundreds of millions of years instead of the hours, minutes, and seconds of its childhood, bringing a new point of calm light to the galaxy’s vast starry ocean. But a flyby of the Dead Star’s surface would have revealed that this calm was illusory. It was an ocean of atomic fire, enormous waves of searing flames that churned red and flung high-energy particles out into space like a storm swell. Tremendous energy erupted from the star’s depths and surged in blinding waves in that sea, over which an endless nuclear storm of constant hurricanes raged, and dark red plasma undulated under a strong magnetic field in million-kilometer tornadoes reaching into space like the tendrils of a red tide… No human mind could grasp the sheer size of the Dead Star; against that sea of fire, Earth was like a basketball tossed into the Pacific Ocean.
The Dead Star ought to have been bright in the visible sky. With an apparent magnitude of .7.5, if not for the interstellar dust incubating another star that sat three light-years distant and blocked its light from reaching Earth, it would have shone on human history with a light more than five times brighter than Sirius, the brightest star in the heavens, bright enough to cast shadows on a moonless night, a dreamy blue adding a dose of sentimentality to human history.
The Dead Star burned a glorious existence without incident for 460 million years, but the cold hand of the law of conservation of energy made certain internal changes unavoidable: the fusion fire depleted hydrogen, and the helium by-product sank to the star’s center and accumulated over time. This change was an exceedingly slow process for such a giant object, one for whom the whole span of human history was the snap of a finger, but after 480 million years, the depletion had a tangible effect: enough of the more inert helium had accumulated that the source of the star’s energy waned. It had grown old.
But other, more complicated physical laws determined that the Dead Star would end its life in a blaze of glory. The density of the helium at its center increased, and the fusion that continued in the surrounding hydrogen produced temperatures high enough to initiate fusion in the helium, consuming nearly all of it at once in a nuclear inferno. The helium fusion caused the Dead Star to shine with a powerful light, but since its energy was only a tenth of that of hydrogen, the effort only further weakened the star. Termed a helium flash by astronomers, the phenomenon’s light reached the patch of interstellar dust three years later, where the relatively long-wavelength red light penetrated the cosmic barrier. That light traveled for another five years before arriving at a far smaller, ordinary star, the Sun, as well as the handful of cosmic dust attracted by its gravitational pull, known to humans as Pluto, Neptune, Uranus, Saturn, Jupiter, Mars, Venus, Mercury, and of course Earth. This took place in 1775.
That evening, in Earth’s northern hemisphere, in the English spa town of Bath, outside a high-end music hall, a German-born organist by the name of Frederick William Herschel was gazing hungrily into the universe through a telescope of his own design. The glittering Milky Way so called to him that he poured his entire life into telescopes, to the extent that his sister Caroline had to spoon him his meals while he continued observations. During the lifetime the most distinguished of eighteenth-century astronomers spent in front of the lens, he marked seventy thousand stars on the map, but he overlooked the one that became most significant to humanity.
That night a red body suddenly appeared in the western sky in the constellation Auriga, at the midpoint between Capella and Beta Aurigae. An apparent magnitude 4.5, it wasn’t bright enough for a casual observer to pick out even if they knew its location, but to an astronomer, the red star was nothing less than an enormous lantern that Herschel might have discovered, were he viewing the heavens with the naked eye like pre-Galilean astronomers rather than being glued to the lens. And that discovery might have altered the course of human history some two centuries later. But his attention was entirely commanded by that telescope, just two inches in diameter, pointed in an entirely different direction, as, unfortunately, were telescopes at the observatories in Greenwich and Hven, and everywhere else in the world, for that matter…
The red star in Auriga shone for the whole night, but the next night it had disappeared.
That same night in that same year, on the continent called North America, eight hundred British soldiers crept along a road to the west of Boston, their red uniforms giving them the look of a line of ghosts in the night. Clutching muskets in the chilly spring wind, they hoped to reach the town of Concord, twenty-seven kilometers from Boston, before daybreak, and were under orders from the Massachusetts governor Thomas Gage to wipe out the minutemen’s arsenal and arrest their leadership. But when the sky turned gray and the woods, huts, and pasture fences took shape as silhouettes against the growing light, the soldiers looked about them and found they had only gotten as far as the town of Lexington. From a thicket ahead of them came a sudden flash, and an earsplitting crack broke the stillness of the North American dawn, closely followed by the whoosh of bullets: the quickening in the womb of the embryonic United States of America.
On the vast continent on the other side of the Pacific, a civilization had already endured for five thousand years. Now, in that ancient land, people were heading day and night toward the capital of that age-old kingdom carrying huge quantities of ancient books collected from every corner of the land. The imperial edict to compile the Sikuquanshu had been issued two years ago, and books were still streaming endlessly toward the capital. In a massive wooden hall in the Forbidden City, the Qianlong Emperor was constantly making the rounds of the rows of bookcases holding the works amassed for the library project, now divided into four general categories, Classics, Histories, Masters, and Collections, and stored on these huge shelves.
Leaving his attendants outside the door, the emperor carefully entered the archives, three scholars wearing peacock feathers on their hats, Dai Zhen, Yao Nai, and Ji Yun, leading the way carrying lanterns. It was they, not the titled imperial clansmen, who were the true compilers of the encyclopedia. The tall cases slipped slowly past the four men, like black city walls in the dim lantern light. They came to a pile of bamboo slips; the emperor picked up one bundle in trembling hands, the wavering yellow light making him feel as if he were at the dark floor of a book canyon, the canyon of time’s mountain, and beneath the book cliff face, countless ghosts from across five thousand years took silently to the air.
“How time flows onward, Your Majesty,” whispered one compiler.
Unimaginably far out in space, the Dead Star continued its march toward doomsday. There were more helium flashes, but smaller in scale than the first, and helium fusion produced a new core of carbon and oxygen. Then that core ignited, producing neon, sulfur, and silicon, and then a huge number of neutrinos appeared in the star, spooky particles that carried off the core’s energy without interacting with any matter.
Over time, the center of the Dead Star grew unable to support its heavy crust, and the gravity that had given it life now worked the reverse. Under gravity’s pull, the Dead Star collapsed into a dense ball, its constituent atoms shattered under the impossibly huge stresses, neutron crushing into neutron. Now a teaspoon of matter from the Dead Star had a mass of a billion tons. First the core collapsed, and then the unsupported crust smashed into the tightly packed center, triggering a final fusion reaction.
An epic of gravity and fire spanning 500 million years came to an end in a cosmos-splitting snow-white blast, and the Dead Star shattered into trillions of fragments and a giant quantity of dust. Its enormous energy, converted into a torrent of EM radiation and high-energy particles, surged outward in all directions. Three years after the explosion, the tide of energy slipped easily through that cosmic dust cloud, heading for the sun.
When the Dead Star exploded, humanity was flourishing eight light-years away. Though they knew they were living on but a speck of dust in the cosmos, they had not truly come to accept this fact. In the millennium that had just ended, they had harnessed the immense power of nuclear fission and fusion and had created complex thinking machines using electrical impulses confined in silicon, imagining they had the power to conquer the universe. No one knew that the energy from the Dead Star was making its inexorable way toward their small blue planet at the speed of light.
After passing the three stars of Centaurus, the Dead Star’s light spent another four years in vast, lonely outer space until at last it reached the outskirts of the solar system. In that region, inhabited only by tailless comets, the energy from the Dead Star had its first encounter with humanity: More than a billion kilometers away from Earth, a man-made body was making its lonely sojourn into the Milky Way—Voyager, an interstellar probe launched from Earth in the 1970s. It was shaped like a weird umbrella, its parabolic antenna opened toward the Earth. The probe carried humanity’s calling card, a lead-alloy plate inscribed with two naked humans, a disc bearing the UN secretary general’s greeting to alien civilization, recordings of Earth’s oceans, birdcalls, and the traditional Chinese tune “Liu Shui.”
Earth had its first taste of the grimness of the cosmos when its emissary to the galaxy passed into the light of the Dead Star and turned immediately into a hunk of blazing metal. Its umbrella antenna warped as its temperature suddenly shot up from near absolute zero. The intensity of the high-energy radiation overloaded a Geiger counter and caused it to read out only zeros. The UV probe and magnetic-field instruments remained operational, and in the just two seconds before the circuits were fried by radiation, Voyager sent back to its creators on Earth a stream of unbelievable data that, owing to the damage to its antenna, would never be received by the high-sensitivity arrays in Nevada and Australia. No matter; humanity would soon be able to measure the unbelievable for themselves.
The Dead Star’s beam crossed the boundary of the solar system and kicked up steam on the blue crystalline solid-nitrogen ground of Pluto, and then met Neptune and Uranus, turning their rings crystal clear. The storm of high-energy particles passed Saturn and Jupiter, phosphorescing their liquid matter, just after the Beijing schoolchildren began their graduation party. The energy traveled for another half hour at light speed and reached the moon, shedding blinding light on Mare Imbrium and the crater of Copernicus. It lit up the set of footprints left behind by Neil Armstrong and Buzz Aldrin four decades earlier under the watchful eyes of hundreds of millions of television viewers on the nearby blue planet, who in that moment of excitement were convinced that the cosmos had been put there for them.
One second later, the Dead Star’s light completed its eight-year journey across space to Earth.
THE MIDNIGHT SUN
It was midday!
That was the children’s first reaction when their vision returned. The light had come so suddenly it was like the flip of some cosmic light switch, and they had been momentarily blinded.
It was 8:18 in the evening, but the children were standing in the blazing light of noon. They looked up into the blue and took in a cold breath. This was most definitely not the same blue as usual; the sky was a startling blue-black, like color recorded on ultrasensitive film. And it seemed unusually clean, as if a grayish-white layer of skin had been peeled off and the sky’s pure-blue flesh was liable to start bleeding at any moment. The city was lit bright by the light, and the sight of the sun made the children cry out in alarm.
This was not humanity’s sun!
The light that had broken into the night sky was too powerful to look at directly, but through the gaps in their fingers they caught glimpses of a sun that wasn’t round—it was a shapeless point like other visible stars, an intense white light emitting from some point in the universe, but it didn’t seem small. It had an extremely high brightness of .51.23, almost an order of magnitude greater than the sun, and its light scattered in the atmosphere, turning it into an enormous, blinding poison spider hanging in the western sky.
The Dead Star appeared suddenly and reached peak brightness in a matter of seconds. Earth’s eastern hemisphere was the first to see it, and the largest panic began almost immediately. Everyone lost all capacity for normal reason and action; the entire world was paralyzed. The spectacle was grandest for viewers in the Atlantic, and on the west coast of Europe and Africa. Here is an eyewitness account from an observer in the Atlantic:
At daybreak we discovered an anomaly: after the sun rose above the ocean, light continued to pour over the eastern horizon, white light, radiating from some unknown source below the surface of the water, as if a huge lamp were hidden beneath the eastern ocean. The light intensified. It was so strange it unsettled everyone on board. There was nothing but static on the radio. The second daybreak grew brighter and brighter, and “dawn” clouds shone with a blinding light, like lightbulb filaments… Our fear grew with the light. We all knew that the light source would rise at some point, but no one knew what we would see. At last, three hours after dawn, we saw a second sunrise. The captain later offered this apt description of the new sun:
“It’s like a giant cosmic welder!” Of the two suns in the sky, it was our old one that was the most frightening: it was so much dimmer than the new one that it looked black by comparison! Not everyone could handle the nightmare, and some people tore madly about the decks, or jumped overboard…
From Albert G. Harris,
A Witness to the Dead Star. London, SE 6.
Before the children on the field had recovered their senses, lightning broke out as the atmosphere ionized under the Dead Star’s radiation. Long purple arcs crossed the sky, and grew denser as earsplitting thunder rolled.
“Quick! Into the classroom!” Zheng shouted, and they all raced back, shielding their heads against the thunder that split the sky and threatened to split the world in two. Once inside, the trembling children clustered around their teacher. The Dead Star’s light shone through the windows on one side casting clear rectangle patterns on the floor; lightning through the windows on the other side flashed that side of the classroom with purple electricity. Static filled the air, metal attachments on their clothing clicked with tiny sparks, their hair stood on end, and they could feel their skin tingling all over, as if their clothing had grown spikes.
Below is a transcript of transmissions between the Russian space station Mir, the Baikonur Cosmodrome in Kazakhstan, and the American space shuttle Zeus, by Mir’s final crew before its deorbiting:
Commander: D. A. Vortsev
Flight engineer: B. G. Tinovich
Mechanical engineer: Y. N. Bykovsky
Environmental engineer: F. Lefsen
Station doctor: Nikita Kasyanenko
Crew: Joe La Mure, solid state physicist; Alexander Andrev, astrophysicist
EM COMMUNICATIONS:
10:20’10”, MIR: Don calling Baikonur! Don calling Baikonur! Base, acknowledge. Base, acknowledge.
(No response. Static.)
10:21’30”, BASE: This is Baikonur base! Baikonur calling Don. Please respond.
(No response. Static.)
INFRARED COMMUNICATIONS:
10:23’20”, MIR: Base, this is Mir. Main system interference is too high, so we’ve initiated backup communications. Please respond.
10:23’25”, BASE: We hear you, but the signal isn’t stable.
10:23’28”, MIR: Difficulty with orienting the transmission and reception units. Orientation control circuit chips have failed due to radiation, so we’ve resorted to manual optical orientation.
10:23’37”, BASE: Fix the transmission and reception units in place. We will take over control.
10:23’42”, MIR: Done.
10:23’43”, BASE: Signal normal!
10:23’46”, MIR: Base, can you tell us what happened? What should we call the thing that appeared all of a sudden?
10:23’46”, BASE: We know as much as you do. Call it “Star X” if you want. Please send us the data you’ve obtained.
10:24’01”, MIR: We will transmit observation data beginning at ten o’clock for the integrated radiometer, ultraviolet and gamma ray instruments, gravimeter, magnetometer, Geiger counter, solar wind meter, and neutrino detector, as well as 136 visual spectrum and infrared images. Prepare to receive.
10:24’30”, MIR: (Data transmission)
10:25’00”, MIR: Our space telescope has been tracking Star X since it first appeared. Given our level of sensitivity, we cannot estimate its angular diameter, nor have we found any clear parallax. Dr. Andrev believes that those two points together with the energy we’ve received mean that Star X is outside the solar system. This is just a hypothesis of course. Data is insufficient, and there’s lots to be done by ground-based observatories.
10:25’30”, BASE: What have you seen on Earth?
10:25’36”, MIR: A large-scale hurricane in the equatorial region is moving northward with an estimated wind speed of 60 meters per second, judging by our observations of the changes in clouds over the equator. This may be due to the unevenness of the sudden influx of heat on Earth from Star X. Oh, and a large amount of ultraviolet radiation and blue flashes, possibly lightning, in the polar regions and currently expanding to lower latitudes.
10:26’50”, BASE: Report on your own status.
10:27’05”, MIR: Not good. The onboard flight control computer has been entirely fried by the high-energy rays, backup systems too. Their lead shielding is inoperative. Monocrystalline silicon solar batteries are totally fried, and chemical batteries are severely damaged. We are now entirely reliant on in-cabin isotope batteries, which are woefully underpowered, so we’ve had to shut down life support in the main cabin. Life support is functioning abnormally in the living cabin. We’re close to having to put on our space suits.
10:28’20”, BASE: The base feels that under the present circumstances it is inadvisable to remain in orbit, but also that a soft landing is impossible given the damage to the systems. The US space shuttle Zeus is in low orbit 3340; it was in Earth’s shadow and suffered only light damage and is still capable of reentry. We have made contact with them, and the Americans have decided to carry out the provisions of the Outer Space Treaty concerning rescue of astronauts and take you on board. Parameters for speed reduction and engine operation to follow…
10:30’33”, MIR: Base, the station doctor wishes to speak with you.
10:30’40”, MIR: This is the station doctor. I believe there’s no point to the transfer. Cancel it.
10:30’46”, BASE: Please explain.
10:30’48”, MIR: All astronauts aboard the station have received an ultra-lethal 5100 rad dose of radiation. We have only hours left to live, so even if we returned to Earth, the outcome would be the same.
10:31’22”, BASE: (Silence)
10:31’57”, MIR: This is the commander. Please allow us to remain on Mir. This station is humanity’s furthest outpost for observing Star X. In our final few hours, we’ll carry out our duties to the full. We will be the first astronauts to die in space; if the opportunity presents itself in the future, please return our remains to our homeland.
From Vladimir Konev, A History of the Russian Space Program in the Common Era, vol. 5. Moscow, SE 17.
The Dead Star lit up the cosmos for an hour and twenty-five minutes before it vanished abruptly. Only then were radio telescope arrays able to detect its remains: a swiftly revolving neutron star emitting a precisely separated EM pulse.
Faces pressed to the classroom window glass, the children watched the sunset that wasn’t, as the blue-black of night descended on this peculiar evening. The light of the Dead Star faded into a twilight that occupied half the sky before quickly shrinking down to a small outlining circle, its color transitioning to white. Most of the sky was dark now, and scattered stars were visible. The halo around the Dead Star continued to contract until it finally vanished, leaving just a point where there once had been a gleaming light source. Once the night sky returned to normal, it was the brightest of the stars, but continued to dim until it was just another star in the galaxy, and five minutes later, the Dead Star had completely vanished into the depths of the cosmos.
When the lightning had stopped, the children ran out of the classroom, where they found themselves in a phosphorescent world. Everything beneath the night sky, the trees, the buildings, the ground, all glowed blue-green, as if the ground and everything on it had been transformed into translucent jade and a green moonlike source deep beneath the ground was flooding light through everything. Green-lit clouds hung in the air as flocks of startled birds sped by like glowing fairies. Most frightening to the children was that they were phosphorescent, too, like images from a photo negative, or a group of ghosts.
“Like I said,” said Specs, “anything can happen.”
The classroom lights turned back on, as did the lights of the city, and the children realized that there had been a blackout. The glow faded as the lights came on, and they initially thought the world had returned to normal. But they soon found to their shock that the episode was not over.
A red light emerged in the northeast, and before long clouds glowing dark red rose in that part of the sky, as if heralding the dawn.
“It’s daybreak for real this time!”
“Idiot! It’s not even eleven!”
The red clouds marched across half the sky, at which point the children realized that they were glowing with their own light. When they were directly overhead, the children could see they were composed of huge bands of light, like strips of slowly twisting red drapes hanging from the sky itself.
“Northern lights!” someone shouted.
The aurora soon covered the whole sky, and for the next week, night skies across the whole world danced with red bands of light.
When the auroras disappeared for good a week later and the glittering stars returned, one final, glorious movement of the supernova’s symphony was left: A shining nebula appeared at the very spot where the Dead Star had been just days before. The explosion’s dust cloud was excited by the high-energy pulse of the star’s remains and emitted synchronized radiation in the visible spectrum for humanity to see. The nebula grew until it was roughly the size of two full moons in the sky. This rosette-shaped radiant body, later given the name “Rose Nebula,” emitted a strange, harsh blue light into the heavens that shone over the earth with a moonlight-like silver, illuminating every detail on the ground with the brightness of a full moon, washing out the glow of the cities below.
The Rose Nebula would shine over human history until the day the inheritors of the dinosaurs’ rule over the planet were wiped out, or were reborn.
Excerpted from Supernova Era, copyright © 2019 by Cixin Liu.
