When a cosmic storm hits, stranding the Nelsons on their new home planet, Nebulon, Zack's hopes of a white Christmas in Vermont are dashed, but Nebulon provides a surprising alternative.

When Cat-Stro-Bot gets into trouble while helping the CatStronauts team with their research on Europa, the CatStronauts defy mission control and undertake a secret mission to save their friend on Jupiter's frozen moon.

Three aliens set off to find a new planet for themselves but soon Bork and Gork have forgotten all of their mother's good advice and only Nklxwcyz builds a home safe enough to withstand the Big Bad Robot in this story reminiscent of "The Three Little Pigs."

A space expert and a geology expert take readers on an out-of-this-world adventure to the moon, where they must navigate the dangerous terrain to clear up space debris before it can interfere with a lunar mission.