Uploaded May 2025 | Updated September 2026, 2 weeks ago

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Mike Merrifield and Seth Shostak discuss a bewildering discovery in NGC 2403... and an offer to its alien inhabitants -- Patreon bonus: patreon.com/posts/129506586 -- Full Shostak video: youtu.be/xy2mE07Pp8E

NGC 2403 is also known at Caldwell 7
Our video on Caldwell 1 - youtu.be/Et2Ij161PXE
Our video on Caldwell 2 - youtu.be/Or3Db6ENf84
Messier 33 - youtu.be/4shqOBkCki8

Seth Shostak: sethshostak.com
Seth Shostak's thesis: core.ac.uk/download/pdf/11812191.pdf

Mike Merrifield is an emeritus professor from the University of Nottingham: about.me/michael.merrifield

Messier Objects playlist: bit.ly/MessierObjects

Back us on Patreon: patreon.com/deepskyvideos

Astronomy at The University of Nottingham: nottingham.ac.uk/astronomy

Twitter: twitter.com/DeepSkyVideos
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Video by Brady Haran and James Hennessy