The Daily Astronomer is published Monday-Friday (except holidays) by Edward Gleason, manager of the Southworth Planetarium in Portland, Maine. Get the Daily Astronomer in your in-box or add this blog to your feed reader to see the latest quizzes, astronomical events, and occasional starstruck silliness.
Detail of false-color image of the supernova remnant Cassiopeia A. Image courtesy NASA / JPL-Caltech / O. Krause (Steward Observatory). See the original plus a full explanation of what's happening here.