A Postcard to the Cosmos: Recreating the Arecibo Signal

This week on Star Trails, we explore the messages written across the cosmos — from faint comets in our own skies to the coded signals we’ve sent into the void. Drew shares a quick report from his local astronomy club’s fall star party, where hopes of photographing Comet A6 Lemmon met the familiar mix of excitement, haze, and grilled hamburgers under imperfect skies.

Then we turn from backyard observing to deep-space communication with a hands-on look at the Arecibo Message — the radio transmission beamed from Earth in 1974 as humanity’s mathematical greeting to the stars. We’ll break down what that signal said, how it was constructed, and whether an alien civilization could ever decode its meaning. Along the way, Drew recreates the original 1,679-bit message using Python code, transforms it into sound, and decodes it again to reveal the famous stick figure, DNA helix, and planetary map.

It’s a story about logic, language, and what it means to say hello to the universe — a reminder that every beam of light and burst of radio energy carries a trace of who we are.

For more episodes and resources for backyard astronomers, visit www.startrails.show. Share the wonder of the stars with friends and continue your cosmic journey with us. Also, connect with us on Bluesky @startrails.bsky.social, or YouTube @TheStarTrailsPodcast.

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