Geronimo discovers a planet on the radar that mysteriously appears and disappears. MouseStar 1 lands to investigate and they discover mysterious aliens who hide a secret!
Age - 7 - 10
Grade - 2 - 5
Category - Early Chapter
Author - Geronimo Stilton
Publisher - Scholastic
Format - Paperback
Pages - 128
Dimensions - 19.2 x 0. 7 x 13.3 cm
