Geronimo Stilton. Spacemice

"Geronimo Stiltonix's spaceship is in danger of exploding! The only solution is to replace the engine's batteries by tracking down a rare element. When a group of mysterious aliens claim they can help, Geronimo is relieved. But are the aliens as friendly as they seem?"--Back cover.

Friends of the spacemice have disappeared on a strange ice planet, Polarix. Geronimo Stiltonix and his crew are called to search for them. When the spacemice arrive on Polarix, they're surprised at the inhabitants--cute little aliens that look like colorful fuzz balls. But are these creatures as harmless as they look?

Geronimo Stilton meets outer space in this cosmically fun spin-off series! Geronimo Stiltonix and his crew head to the planet Jurassix to warn its inhabitants of a giant comet heading straight toward them! But the creatures there turn out to be ferocious, dinosaur-like beasts . . . who like to eat rodents. Squeak! Can the spacemice save these aliens and still make it out alive?

MouseStar 1 is surrounded by floating space junk! It's yucky -- and dangerous. It's coming from a nearby planet, Cleanix. Geronimo Stiltonix goes to visit, and discovers that the aliens there are very wasteful. Even worse, robots that they've thrown in the trash have started to rebel! Can the spacemice restore harmony before the robots take over?

Geronimo Stiltonix and his spacemice crewmates travel to a planet where delicious mozzarella grows in order to restore harmony between its alien inhabitants and the cheese-loving slurp monster.

"Professor Greenfur, the onboard scientist on spaceship MouseStar 1, has changed color from green to... orange! What's going on? To find out, the spacemice travel to his home planet of Photosyntheson. There, they learn that all of Professor Greenfur's relatives are being threatened by the nibblix, tiny aliens with very sharp teeth! Can the spacemice help in time?" --