The fascination with astronomy and space travel may not be the national craze it was way back when we earthlings were making our first forays into the vast unknown.

But the idea of scientific exploration in the far reaches of the galaxy can still excite young minds — with a little help, maybe, from fictions like the hit movie “Gravity” (about an astronaut lost in space) and the new show at Seattle Children’s Theatre, “The Boy at the Edge of Everything.”

Finegan Kruckemeyer’s engaging fable is receiving its world premiere here in conjunction with New York’s Trusty Sidekick Theater Company. Its clever premise: Simon, a disgruntled 12-year-old (zestfully played by the ever-boyish Trick Danneker) is hurtled out into the far reaches of the sky to make friends with another boy (crisply enacted by Quinn Armstrong). The latter lives a bookish solo existence on the edge of our universe — in a house with a great view, perched between worlds.

Simon’s whimsical journey is made possible thanks to an empty meditation tank and a batch of fireworks, rigged up in the family’s shed by his well-meaning parents (Carol Roscoe and Evan Whitfield).

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And he’s glad to blast off, given the condition he shares with many other American adolescents: over-schedule-itis. Between the demands of school, sports, other activities, and his loving but noisy, overattentive relations, Simon longs “to travel to a place far, far away,” somewhere “you can just sit and be.”

Meanwhile, his (unnamed) counterpart in deep space worries other planets may be encroaching on him. But he too would like a change from reading through his vast library many times over, and playing with “a model train set that goes through three galaxies.”

Through their fast friendship, the pair get to know each other’s turf. And like Dorothy in “The Wizard of Oz,” Simon discovers how vast the world is beyond his own experience — and how much he’s underappreciated his home sweet home.

“The Boy at the Edge of Everything” has a canny, witty way of reflecting on worlds unknown, and day-to-day adolescent routines. At a matinee performance, a tween-age crowd listened up for every wisecrack and reflection in Kruckemeyer’s snappy yet sincere dialogue.

And how refreshing it is that Jonathan Shmidt Chapman’s staging of the play in the small-scale Eve Alvord Theatre at SCT relies not on flashy hardware or digital special effects. What lifts us off on this astronomical journey are the nimble and likable cast, the ace design team, and the young audience’s willingness to suspend disbelief.

Carey Wong’s set conflates the universe into the curving frame of a shed resembling a solar panel, an array of useful boxes and a scrunched cottage. Andrew Smith’s excellent lighting design also plays a key role in the storytelling, as the sky fills with twinkling stars, and darkens for some cool effects with glowing, handheld planets.

The one thing obviously missing from “The Boy at the Edge of Everything” is any explanation of the origins of the super-bright title character. Ageless, alone and hyper-aware of the scientific marvels he observes, the kid is just the friend Simon needs (and vice-versa). But is he an extraterrestrial? A human being? Who raised him, and why is he hanging out in a place light-years from Earth?

Those matters are not broached in the play, certainly deliberately. We are left to fill in the blanks, with our own imaginations.

Misha Berson: