Movies like The Phantom Planet

Aliens have landed and are hiding on Earth, but need Earth’s scientists to help them fight an inter-planetary war.

The first manned expedition to Mars is invaded by an unknown life form, which stows away on the rescue ship.

Humanity finds a mysterious object buried beneath the lunar surface and sets off to find its origins with the help of HAL 9000, the world's most advanced super computer.

Starship C57D travels to planet Altair 4 in search of the crew of spaceship "Bellerophon," a scientific expedition that has been missing for twenty years. They find themselves unwelcome by the expedition's lone survivor and warned of destruction by an invisible force if they don't turn back immediately.

Author and amateur astronomer John Putnam and schoolteacher Ellen Fields witness an enormous meteorite come down near a small town in Arizona. Putnam becomes a local object of scorn when, after examining the object up close, he announces that it is a spacecraft, and that it is inhabited...

A small-town doctor learns that the population of his community is being replaced by emotionless alien duplicates.

In the 28th century, Valerian and Laureline are special operatives charged with keeping order throughout the human territories. On assignment from the Minister of Defense, the two undertake a mission to Alpha, an ever-expanding metropolis where species from across the universe have converged over centuries to share knowledge, intelligence, and cultures. At the center of Alpha is a mysterious dark force which threatens the peaceful existence of the City of a Thousand Planets, and Valerian and Laureline must race to identify the menace and safeguard not just Alpha, but the future of the universe.

16-year-old Cassie Sullivan tries to survive in a world devastated by the waves of an alien invasion that has already decimated the population and knocked mankind back to the Stone Age.

A dangerous combination of radiation and insecticide causes the unfortunate Scott Carey to shrink, slowly but surely, until he is only a few inches tall. His home becomes a wilderness where he must survive everything from spiders living in the cellar to his beloved cat.

John Carter is a war-weary, former military captain who's inexplicably transported to the mysterious and exotic planet of Barsoom (Mars) and reluctantly becomes embroiled in an epic conflict. It's a world on the brink of collapse, and Carter rediscovers his humanity when he realizes the survival of Barsoom and its people rests in his hands.

The explorer craft USS Palomino is returning to Earth after a fruitless 18-month search for extra-terrestrial life when the crew comes upon a supposedly lost ship, the USS Cygnus, hovering near a black hole. The ship is controlled by Dr. Hans Reinhardt and his monstrous robot companion, but the initial wonderment and awe the Palomino crew feel for the ship and its resistance to the power of the black hole turn to horror as they uncover Reinhardt's plans.

When the first manned flight to Venus returns to Earth, the rocket crash-lands in the Mediterranean near a small Italian fishing village. The locals manage to save Colonel Robert Calder, the mission commander. A young boy also recovers what turns out to be a specimen of an alien creature. Growing at a fantastic rate, it manages to escape and eventually threatens the city of Rome.