John Perry did two things on his 75th birthday. First he visited his wife's grave. Then he joined the army. The good news is that humanity finally made it into interstellar space. The bad news is that planets fit to live on are scarce—and alien races willing to fight us for them are common. So: we fight. To defend Earth, and to stake our own claim to planetary real estate. Far from Earth, the war has been going on for decades: brutal, bloody, unyielding. Earth itself is a backwater.

Set against the backdrop of China's Cultural Revolution, a secret military project sends signals into space to establish contact with aliens. An alien civilization on the brink of destruction captures the signal and plans to invade Earth. Meanwhile, on Earth, different camps start forming, planning to either welcome the superior beings and help them take over a world seen as corrupt, or to fight against the invasion. The result is a science fiction masterpiece of enormous scope and vision.

There's a reason We Are Legion was named Audible's Best Science Fiction Book of 2016: Its irresistibly irreverent wit! Bob Johansson has just sold his software company for a small fortune and is looking forward to a life of leisure. The first item on his to-do list: Spending his newfound windfall. On an urge to splurge, he signs up to have his head cryogenically preserved in case of death. Then he gets himself killed crossing the street. Waking up 117 years later, Bob discovers his mind has been uploaded into a sentient space probe with the ability to replicate itself.

On the world called Hyperion, beyond the law of the Hegemony of Man, there waits the creature called the Shrike. 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.

Winner of the 1961 Hugo Award for Best Novel and widely considered one of the most accomplished, powerful, and enduring classics of modern speculative fiction, Walter M. Miller’s A Canticle for Leibowitz is a true landmark of 20th-century literature—a chilling and still-provocative look at a postapocalyptic future.

Adrian Tchaikovksy's critically acclaimed stand-alone novel Children of Time is the epic story of humanity's battle for survival on a terraformed planet. Who will inherit this new Earth? The last remnants of the human race left a dying Earth, desperate to find a new home among the stars. Following in the footsteps of their ancestors, they discover the greatest treasure of the past age - a world terraformed and prepared for human life. But all is not right in this new Eden.

In what is considered one of Heinlein's most hair-raising, thought-provoking, and outrageous adventures, the master of modern science fiction tells the strange story of an even stranger world. It is 21st-century Luna, a harsh penal colony where a revolt is plotted between a bashful computer and a ragtag collection of maverick humans, a revolt that goes beautifully until the inevitable happens. But that's the problem with the inevitable: it always happens.

When prospector Bob 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, Robinette Broadhead has to face what happened to him and what he is...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!

A Fire Upon the Deep is the big, breakout book that fulfills the promise of Vinge's career to date: a gripping tale of galactic war told on a cosmic scale. Thousands of years hence, many races inhabit a universe where a mind's potential is determined by its location in space, from superintelligent entities in the Transcend, to the limited minds of the Unthinking Depths, where only simple creatures and technology can function.

Joe Haldeman is the esteemed Hugo and Nebula Award-winning author of The Forever War. Things are going nowhere for lowly MIT research assistant Matt Fuller - especially not after his girlfriend drops him for another man. But then while working late one night, he inadvertently stumbles upon what may be the greatest scientific breakthrough ever. His luck, however, runs out when he finds himself wanted for murder - in the future.

Six million years ago, at the very dawn of the starfaring era, Abigail Gentian fractured herself into a thousand male and female clones: the shatterlings. Sent out into the galaxy, these shatterlings have stood aloof as they document the rise and fall of countless human empires. They meet every 200,000 years to exchange news and memories of their travels with their siblings.

At first, only a few things are known about the celestial object that astronomers dub Rama. It is huge, weighing more than ten trillion tons. And it is hurtling through the solar system at 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.

Earth is long since dead. 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.

The Mote In God's Eye is their acknowledged masterpiece, an epic novel of mankind's first encounter with alien life that transcends the genre. No lesser an authority than Robert A. Heinlein called it "possibly the finest science fiction novel I have ever read".

The Overlords appeared suddenly over every city - intellectually, technologically, and militarily superior to humankind. Benevolent, they made few demands: unify earth, eliminate poverty, and end war. With little rebellion, humankind agreed, and a golden age began.

In the 20th century Earth sent probes, transmissions, and welcoming messages to the stars. Unfortunately, someone noticed. The Galactics arrived with their battle fleet in 2052. Rather than being exterminated under a barrage of hell-burners, Earth joined their vast Empire. Swearing allegiance to our distant alien overlords wasn't the only requirement for survival. We also had to have something of value to trade, something that neighboring planets would pay their hard-earned credits to buy. As most of the local worlds were too civilized to have a proper army, the only valuable service Earth could provide came in the form of soldiers....

The Year is 2040. The Marines have landed on Mars to guard the unearthed secrets of an ancient and dangerous alien race: Ourselves. Scientists have discovered something astonishing in the subterranean ruins of a sprawling Martian city: startling evidence of an alternative history that threatens to split humanity into opposing factions and plunge the Earth into chaos and war.

In the future, the terminally ill can prolong life by surrendering their consciousness to a cybernetic life form that is then recruited into the notorious Legion of the Damned, an elite fighting unit charged with protecting humanity.

They first appear as a series of dots on astronomical plates, heading from Saturn directly toward Earth. Since the ringed planet carries no life, scientists deduce the mysterious ship to be a visitor from another star. The world's frantic efforts to signal the aliens go unanswered. The first contact is hostile: the invaders blast a Soviet space station, seize the survivors, and then destroy every dam and installation on Earth with a hail of asteriods.

One hundred years from now, Russia and the United States are at odds again. This time the war has gone hot. Heavily armored soldiers battle genetically engineered troops hundreds of meters below the icy, mineral-rich mountains of Kazakhstan. War is Oscar Wendell’s ticket to greatness. A reporter for the Stars and Stripes, he has the only one-way ticket to the front lines. The front smells of blood and fire and death—it smells like a Pulitzer.

The Hundred Worlds have withstood invasion by the relentless Hok for decades. The human worlds are strong, but the Hok have the resources of a thousand planets behind them, and their fleets attack in endless waves. The long war has transformed the Hundred Worlds into heavily fortified star systems. Their economies are geared for military output, and they raise specialized soldiers to save our species. Assault Captain Derek Straker is one such man among many.

In the wilds of a jungle planet, the Legion fights in brutal combat as Republic marines fly their SLICS from one tragedy to the next. H292, a repurposed warbot, shows the heart of a hero as he wades into the battle not to destroy - but to save.

Passage at Arms tells the intimate, detailed and harrowing story of a climber crew and its captain during a critical juncture of the war. Cook combines speculative technology with a canny and realistic portrait of men at war and the stresses they face in combat. Passage at Arms is one of the classic novels of military science fiction.

Kris Longknife is a daughter of privilege, born to money and power. Her father is the prime minister of her home planet, her mother the consummate politician's wife. She's been raised only to be beautiful and marry well. But the heritage of the military Longknifes courses through Kris' blood - and, against her parents' objections, she enlists in the Marines.

With Earth in the path of the rapacious Posleen, the Galactic Federation offers help to the backward humans - for a price. You can protect yourself from your enemies, but God save you from your allies!

The plot by the Galactic Union’s Mercenary Guild against the Four Horsemen has culminated in an invasion of Earth. Faced with an overwhelming force, the human mercs had no choice. They’ve fled, leaving Sansar Enkh to go to the Mercenary Guild headquarters on Capital Planet to stand trial for humanity. On the run, Jim Cartwright and Nigel Shirazi have travelled to the Winged Hussars’ secret base of New Warsaw, in an effort to convince Alexis Cromwell to join the fight, while the other mercenaries who escaped the fall of Earth have gone to the perceived safe haven of Karma.

He raised an army against those who took everything from him. They should have picked their enemies more carefully. Five centuries from now, on a remarkably Earthlike planet that is mankind's sole colony in space, religious fanatics called the "Salafi Ikhwan" have murdered the uncle of former colonel Patrick Hennessey. That was their first mistake, because uncle was rich and Hennessey was rather a good colonel. But they also murdered Hennessey's wife, Linda, and their three small children, and that was their worst mistake for she was the only restraint Hennessey had ever accepted.

In AD 2600, the human race is finally beginning to realize its full potential. Hundreds of colonized planets scattered across the galaxy host a multitude of prosperous and wildly diverse cultures. Genetic engineering has pushed evolution far beyond nature's boundaries, defeating disease and producing extraordinary spaceborn creatures. Huge fleets of sentient trader starships thrive on the wealth created by the industrialization of entire star systems, and throughout inhabited space the Confederation Navy keeps the peace.

Young Carmen Dula and her family are about to embark on the adventure of a lifetime - they're going to Mars. Once on the Red Planet, however, Carmen realizes things are not so different from Earth. There are chores to do, lessons to learn, and oppressive authority figures to rebel against.

The Ember War, book 1: The Earth is doomed. Humanity has a chance. In the near future, an alien probe arrives on Earth with a pivotal mission: to determine if humanity has what it takes to survive the impending invasion by a merciless armada. The probe discovers Marc Ibarra, a young inventor who holds the key to a daring gambit that could save a fraction of Earth's population. Humanity's only chance lies with Ibarra's ability to keep a terrible secret and engineer the planet down the narrow path to survival.

Winner of the Hugo and Nebula Awards, Joe Haldeman has penned several best-selling novels, including The Forever War. After receiving a message from deep space, astronomer Aurora “Rory” Bell anticipates extraterrestrial visitors on New Year’s Eve. But with Earth teetering on the edge of another world war, Rory soon begins to wonder if the message was a hoax. And when the message is leaked to the public, a media frenzy ensues.

Marooned in outer space after an attack on his ship, Nomad, Gulliver Foyle lives to obsessively pursue the crew of a rescue vessel that had intended to leave him to die.

Joe Haldeman is the esteemed Hugo and Nebula Award-winning author of The Forever War. Things are going nowhere for lowly MIT research assistant Matt Fuller - especially not after his girlfriend drops him for another man. But then while working late one night, he inadvertently stumbles upon what may be the greatest scientific breakthrough ever. His luck, however, runs out when he finds himself wanted for murder - in the future.

Six million years ago, at the very dawn of the starfaring era, Abigail Gentian fractured herself into a thousand male and female clones: the shatterlings. Sent out into the galaxy, these shatterlings have stood aloof as they document the rise and fall of countless human empires. They meet every 200,000 years to exchange news and memories of their travels with their siblings.

Winner of the Nebula Award for Best Novel, Red Mars is the first book in Kim Stanley Robinson's best-selling trilogy. Red Mars is praised by scientists for its detailed visions of future technology. It is also hailed by authors and critics for its vivid characters and dramatic conflicts.

For centuries, the red planet has enticed the people of Earth. Now an international group of scientists has colonized Mars. Leaving Earth forever, these 100 people have traveled nine months to reach their new home. This is the remarkable story of the world they create - and the hidden power struggles of those who want to control it.

The artifact is found seven miles below the surface of the sea and beneath 40 more feet of sand. The Navy's efforts to raise a wrecked submarine uncover it - and set in motion a scientific race to retrieve it, to discover just what it is and where it came from. Denser than any substance known to man, it has broken every drill bit they've tried on it and will not budge an inch. It resists every effort to breach it - or communicate with it.

Welcome to Ringworld, an intermediate step between Dyson Spheres and planets. The gravitational force created by a rotation on its axis of 770 miles per second means no need for a roof. Walls 1,000 miles high at each rim will let in the sun and prevent much air from escaping. Larry Niven's novel, Ringworld, is the winner of the 1970 Hugo Award for Best Novel, the 1970 Nebula Award for Best Novel, and the 1972 Ditmars, an Australian award for Best International Science Fiction.

Belisarius is a quantum man, an engineered Homo quantus who fled the powerful insight of dangerously addictive quantum senses. He found a precarious balance as a con man, but when a client offers him untold wealth to move a squadron of warships across an enemy wormhole, he must embrace his birthright to even try. In fact, the job is so big that he'll need a crew built from all the new sub-branches of humanity. If he succeeds, he might trigger an interstellar war, but success might also point the way to the next step of Homo quantus evolution.

Nine hundred thousand years ago, something annihilated the Amarantin civilization just as it was on the verge of discovering space flight. 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.

2057. Humanity has raised exploiting the solar system to an art form. Bella Lind and the crew of her nuclear-powered ship, the Rockhopper, push ice. They mine comets. And they're good at it. The Rockhopper is nearing the end of its current mission cycle, and everyone is desperate for some much-needed R & R, when startling news arrives from Saturn: Janus, one of Saturn's ice moons, has inexplicably left its natural orbit and is now heading out of the solar system at high speed.

Earth is long since dead. 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.