APOD: 2026 October 21 – New Ghosts Revealed in Cassiopeia. APODScienceAPODAPOD: 2026 October 21 – New…Today’s APODArchiveSubmissionsIndexSearchCalendarRSSEducationAboutDiscuss APOD Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. OriginalAnnotated New Ghosts Revealed in Cassiopeia Explanation: Jinkies, look at all those ghosts! It took 100 […].