The Black Moon & the Milky Way’s Hidden Companions

Under a rare seasonal Black Moon, this week’s sky rewards early risers and deep-sky wanderers alike. We start with a whisper-thin crescent slipping closer to the Sun each morning, then pivot to a dawn showcase where Mercury reaches greatest elongation while Venus and Jupiter stack higher above the horizon. On Tuesday and Wednesday a paper-thin crescent Moon joins the lineup—a perfect wide-field photo op—while evenings bring Saturn rising into prime viewing on its road to September opposition. With moonlight out of the way, scan the Milky Way for under-sung binocular treats: Delphinus the Dolphin, M11 (Wild Duck Cluster) in Scutum, and the Coathanger asterism in Vulpecula. You may even catch a few Perseid stragglers in the pre-dawn dark.

In the second half, we widen the frame to reveal the Milky Way’s “hidden companions”—dozens, maybe hundreds, of ultra-faint dwarf galaxies quietly orbiting our own. We unpack why they’re so hard to see (surface brightness, not just brightness), how modern surveys like SDSS and DES ferret them out, and why they matter for big questions about dark matter, galaxy growth, and the “missing satellites” problem.

Links in this episode:

• Sloan Digital Sky Survey
• The Dark Energy Survey
• Gaia Sky

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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