Ringworld


Larry Niven - 1970
    Pierson's puppeteers, the aliens who discovered it, are understandably wary of encountering the builders of such an immense structure and have assembled a team of two humans, a mad puppeteer and a kzin, a huge cat-like alien, to explore it. But a crash landing on the vast edifice forces the crew on a desperate and dangerous trek across the Ringworld.

Hyperion


Dan Simmons - 1989
    There are those who worship it. There are those who fear it. And there are those who have vowed to destroy it. In the Valley of the Time Tombs, where huge, brooding structures move backward through time, the Shrike waits for them all. On the eve of Armageddon, with the entire galaxy at war, seven pilgrims set forth on a final voyage to Hyperion seeking the answers to the unsolved riddles of their lives. Each carries a desperate hope—and a terrible secret. And one may hold the fate of humanity in his hands.

Spin


Robert Charles Wilson - 2005
    They all flared into brilliance at once, then disappeared, replaced by a flat, empty black barrier. He and his best friends, Jason and Diane Lawton, had seen what became known as the Big Blackout. It would shape their lives.Life on Earth is about to get much, much stranger.

Rendezvous with Rama


Arthur C. Clarke - 1973
    It is huge, weighing more than ten trillion tons. And it is hurtling through the solar system at an inconceivable speed. Then a space probe confirms the unthinkable: Rama is no natural object. It is, incredibly, an interstellar spacecraft. Space explorers and planet-bound scientists alike prepare for mankind's first encounter with alien intelligence. It will kindle their wildest dreams... and fan their darkest fears. For no one knows who the Ramans are or why they have come. And now the moment of rendezvous awaits — just behind a Raman airlock door.

The Forever War


Joe Haldeman - 1974
    A reluctant conscript drafted into an elite Military unit, Private William Mandella has been propelled through space and time to fight in the distant thousand-year conflict; to perform his duties without rancor and even rise up through military ranks. Pvt. Mandella is willing to do whatever it takes to survive the ordeal and return home. But "home" may be even more terrifying than battle, because, thanks to the time dilation caused by space travel, Mandella is aging months while the Earth he left behind is aging centuries.

The Gods Themselves


Isaac Asimov - 1972
    But even free energy has a price. The transference process itself will eventually lead to the destruction of the Earth's Sun--and of Earth itself.Only a few know the terrifying truth--an outcast Earth scientist, a rebellious alien inhabitant of a dying planet, a lunar-born human intuitionist who senses the imminent annihilation of the Sun.  They know the truth--but who will listen?  They have foreseen the cost of abundant energy--but who will believe?  These few beings, human and alien, hold the key to the Earth's survival.

Red Mars


Kim Stanley Robinson - 1992
    For centuries, Mars has beckoned humans to conquer its hostile climate. Now, in 2026, a group of 100 colonists is about to fulfill that destiny.John Boone, Maya Toitavna, Frank Chalmers & Arkady Bogdanov lead a terraforming mission. For some, Mars will become a passion driving them to daring acts of courage & madness. For others it offers an opportunity to strip the planet of its riches. For the genetic alchemists, it presents a chance to create a biomedical miracle, a breakthrough that could change all we know about life & death. The colonists orbit giant satellite mirrors to reflect light to the surface. Black dust sprinkled on the polar caps will capture warmth. Massive tunnels, kilometers deep, will be drilled into the mantle to create stupendous vents of hot gases. Against this backdrop of epic upheaval, rivalries, loves & friendships will form & fall to pieces--for there are those who will fight to the death to prevent Mars from ever being changed.Brilliantly imagined, breathtaking in scope & ingenuity, Red Mars is an epic scientific saga, chronicling the next step in evolution, creating a world in its entirety. It shows a future, with both glory & tarnish, that awes with complexity & inspires with vision.

Revelation Space


Alastair Reynolds - 2000
    Now one scientist, Dan Sylveste, will stop at nothing to solve the Amarantin riddle before ancient history repeats itself. With no other resources at his disposal, Sylveste forges a dangerous alliance with the cyborg crew of the starship Nostalgia for Infinity. But as he closes in on the secret, a killer closes in on him. Because the Amarantin were destroyed for a reason — and if that reason is uncovered, the universe—and reality itself — could be irrecoverably altered….

Gateway


Frederik Pohl - 1977
    and on reaches of unimaginable horror. When prospector Robinette Broadhead went out to Gateway on the Heechee spacecraft, he decided he would know which was the right mission to make him his fortune. Three missions later, now famous and permanently rich, Rob Broadhead has to face what happened to him and what he has become... in a journey into himself as perilous and even more horrifying than the nightmare trip through the interstellar void that he drove himself to take!

Lord of Light


Roger Zelazny - 1967
    On a colony planet, a band of men has gained control of technology, made themselves immortal, and now rule their world as the gods of the Hindu pantheon. Only one dares oppose them: he who was once Siddhartha and is now Mahasamatman. Binder of Demons, Lord of Light.

Eon


Greg Bear - 1985
    NASA, NATO, and the UN sent explorers to the asteroid's surface...and discovered marvels and mysteries to drive researchers mad.For the Stone was from space--but perhaps not our space; it came from the future-but perhaps not our future; and within the hollowed asteroid was Thistledown. The remains of a vanished civilization. A human--English, Russian, and Chinese-speaking--civilization. Seven vast chambers containing forests, lakes, rivers, hanging cities...And museums describing the Death; the catastrophic war that was about to occur; the horror and the long winter that would follow. But while scientists and politicians bickered about how to use the information to stop the Death, the Stone yielded a secret that made even Earth's survival pale into insignificance.

Consider Phlebas


Iain M. Banks - 1987
    Billions had died, billions more were doomed. Moons, planets, the very stars themselves, faced destruction, cold-blooded, brutal, and worse, random. The Idirans fought for their Faith; the Culture for its moral right to exist. Principles were at stake. There could be no surrender.Within the cosmic conflict, an individual crusade. Deep within a fabled labyrinth on a barren world, a Planet of the Dead proscribed to mortals, lay a fugitive Mind. Both the Culture and the Idirans sought it. It was the fate of Horza, the Changer, and his motley crew of unpredictable mercenaries, human and machine, actually to find it, and with it their own destruction.

Way Station


Clifford D. Simak - 1963
    But what his neighbors must never know is that, inside his unchanging house, he meets with a host of unimaginable friends from the farthest stars.More than a hundred years before, an alien named Ulysses had recruited Enoch as the keeper of Earth's only galactic transfer station. Now, as Enoch studies the progress of Earth and tends the tanks where the aliens appear, the charts he made indicate his world is doomed to destruction. His alien friends can only offer help that seems worse than the dreaded disaster. Then he discovers the horror that lies across the galaxy...

Double Star


Robert A. Heinlein - 1956
    Then a space pilot bought him a drink, and the next thing Smythe knew, he was shanghaied to Mars.Suddenly he found himself agreeing to the most difficult role of his career: impersonating an important politician who had been kidnapped. Peace with the Martians was at stake — failure to pull off the act could result in interplanetary war. And Smythe's own life was on the line — for if he wasn't assassinated, there was always the possibility that he might be trapped in his new role forever!

Pandora's Star


Peter F. Hamilton - 2004
    The Intersolar Commonwealth, a sphere of stars some four hundred light-years in diameter, contains more than six hundred worlds, interconnected by a web of transport "tunnels" known as wormholes. At the farthest edge of the Commonwealth, astronomer Dudley Bose observes the impossible: Over one thousand light-years away, a star... vanishes. It does not go supernova. It does not collapse into a black hole. It simply disappears. Since the location is too distant to reach by wormhole, a faster-than-light starship, the Second Chance, is dispatched to learn what has occurred and whether it represents a threat. In command is Wilson Kime, a five-time rejuvenated ex-NASA pilot whose glory days are centuries behind him.Opposed to the mission are the Guardians of Selfhood, a cult that believes the human race is being manipulated by an alien entity they call the Starflyer. Bradley Johansson, leader of the Guardians, warns of sabotage, fearing the Starflyer means to use the starship's mission for its own ends.Pursued by a Commonwealth special agent convinced the Guardians are crazy but dangerous, Johansson flees. But the danger is not averted. Aboard the Second Chance, Kime wonders if his crew has been infiltrated. Soon enough, he will have other worries. A thousand light-years away, something truly incredible is waiting: a deadly discovery whose unleashing will threaten to destroy the Commonwealth... and humanity itself. Could it be that Johansson was right?