Twelve-year-old Arcturus Betelgeuse Chambers comes from a family of stargazers and his quest to find life on other planets is unstoppable.

But when Arty's family announces they're moving to Las Vegas, the City of Lights threatens to put an end to his stargazing dreams forever―especially when he has to stay with his scary next door neighbor while his parents look for a house. As it turns out, "Mr. Death" isn't terrifying at all―he's actually Cash Maddox, a bonafide astronaut! But when Cash falls ill, will Arty find the courage to complete his mission by himself? And might he actually prove, once and for all, that there is life on Mars?

For fans of Frank Cottrell Boyce's Cosmic and Jack Gantos's Dead End in Norvelt comes a heartwarming story of true friendship―earthly or otherwise.