The latest addition to the dozens of Goodnight Moon pastiches takes a cosmic angle.In nods to tradition, the room is green, the narrative properly sonorous, and there's a blank "Goodnight nobody" page. The resemblance largely ends there, as the visible furnishings are decidedly astronomical in theme, the bed is replaced by a work desk, the drowsy bunny by an alert young STEM-winder with light-brown skin intent on her computer screen, and the grandmotherly attendant by a "quiet old scientist who was whispering ‘globular.' " (Rather creepily, this last figure is a White man.) Likewise, taking an even looser approach to meter and rhyme than Margaret Wise Brown did, Arcand tallies the room's contents ("And there were three little astronomers sitting with monitors // And two little interns / And a pair of emergency lanterns," etc.) before launching a nocturne to the speckled exomoon orbiting a ringed planet that looks like Saturn (but isn't) visible through a window. The final "Goodnight stars / Goodnight air // Goodnight space science everywhere" caps an incantation that, however familiar its rhythms, is more likely to leave young listeners thinking, "What's an accelerometer?" than blinking sleepily. Caregivers hazy on what an "exomoon" is will welcome the author's prefatory explanation. Human figures, from "little interns" on, are diverse of skin color.A twinkly, labored lullaby to all the moons we know are out there but can't (as yet) see. (Board book. 2-6)