Cannonball Express is a peculiar planet of extragalactic origin orbiting around a protosun in the edges of Known Space. It's made up of antimatter.[1]
It's described as having no atmosphere and no lithosphere, the latter most likely the result of encountering normal matter in its trajectory creating tiny explosions that have stripped it of its lithosphere as well making its surface look polished and craterless. It has a dull white color.[1]
The planet is home to helium II based life described as looking like rather big blue blobs from a distance and living on the side of the planet sheltered from normal matter interstellar wind.[1]
The location of Cannonball Express and its system was revealed by the Outsiders to Elephant and Beowulf Shaeffer in exchange of one million stars, after the former contacted them in search of a must unusual planet.[1]
Elephant was also responsible for the naming of the planet after having his firs suggestion of Cue Ball rejected due to this being already the name of another planet orbiting around Beta Lyrae.[1]