Books like Alien abductions by Martin H. Greenberg

When the massive Fithp spacecraft from Alpha Centauri arrives in the Solar System, humanity faces a bold and terrifying challenge: an extraterrestrial species intent on conquering Earth.

When Earth faces a hidden alien invasion, Rachel and her friends discover they are the only ones who can defend the planet.

NASA astronaut Nigel Walmsley intercepts a rogue asteroid that turns out to be a derelict probe emitting a lone signal. Years later, a reply from outside the solar system reveals a sentient alien ship planning humanity’s annihilation.

When a strange new substitute teacher arrives at a sixth‑grade school, two students discover he is an alien with a sinister plan that could end their class. They must act quickly to save their classmates from an extraterrestrial threat.

After a post‑World II alien virus granted a handful of survivors superhuman abilities, Wild Cards #2 follows these heroes and villains through the turbulent 1980s.

In Communion, Whitley Strieber recounts the extraordinary encounters he and his family experienced with intelligent non‑human beings in an upstate New York cabin.

A humorous adventure where a group of kids, led by Peter Thompson, encounters three aliens disguised as classmates while the extraterrestrials work on a crucial report that could shape Earth’s future.

On the planet Lorca, the USS Enterprise crew adopts the world’s ceremonial masks to negotiate with its ruler, while a rival search led by Riker unwittingly entangles them in a madman’s elaborate trap for the Wisdom Mask.

The reluctant hero of this hilarious novel is John Oliver Banion, a stuffy Washington talk-show host, whose privileged life is thrown into upheaval when aliens abduct him from his exclusive country-club golf course. But were his gray-skinned captors aliens...or something far more sinister? After Banion is abducted again - this time in Palm Springs - he believes he has been chosen by the extraterrestrials to champion the most important cause of the millennium, and he embarks on a crusade, appearing before a convention of UFO believers and demanding that Congress and the White House seriously investigate UFOs. His friends and family suspect that Banion is having some kind of manic-depressive midlife crisis and urge him to seek therapy before his credibility as a pillar of the punditocracy is ruined. So John Oliver Banion must choose: keep his establishment status or become the leader of millions of impassioned and somewhat scruffy new friends who want to expose the government's secret alien agenda.

A story of Rome's legendary legions, trapped by aliens, fighting barbarian armies across the galaxy to regain freedom and honor their legacy and humanity's worth in the universe's eyes.

A giant artificial world stops in the solar system, threatening Earth with disastrous consequences.

A book about Earth being involved in an intergalactic war with alien race humans being 'peace engineers'.

When humanity stretches its lifespan into millennia and leaves Earth for the stars, a sudden drop in the planet’s population sets off a mystery. A distant star‑rover will uncover why Earth's original inhabitants are returning to reclaim their heritage.