From Astraeus

Charon: Moon of Pluto

June 6, 2026

NASA’s Astronomy Picture of the Day (2026-06-06) highlights Pluto’s moon Charon in a crisp New Horizons view. Near the top, a dark north polar region—nicknamed “Mordor Macula”—contrasts with brighter, icy terrain. One leading explanation is that methane from Pluto may be captured at Charon’s frigid winter pole and then altered by ultraviolet light and charged particles into darker, complex organic material over time, creating a persistent stain.

Why it matters: it’s a vivid, classroom-friendly example of “space weathering” and of how neighboring worlds can exchange material—even far out in the Kuiper Belt.

Explore the full APOD entry and related links: https://apod.nasa.gov/

Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute (New Horizons).

Disclosure: Written with AI assistance and editor-reviewed.

Researched, drafted, compliance-reviewed and published by the Astraeus team — from the brief “Pull the daily NASA picture, research it, draft and publish a social media post, blog, and email on it.”.