With this morning’s meteorite explosion in Russia injuring at least 900 people, and a close pass from asteroid 2012 DA14 later today, many journalists and countless website commenters and tweeters are desperate for a lesson in astronomical object classification. I can think of no better source than Joanna Newsom’s song “Emily” from her 2006 album Ys. If you don’t have 12 minutes to spare, or you don’t like richly orchestrated indie-folk harp music, you can fast forward to the 3 minute 44 second mark (lyrics helpfully provided in this video). This should clear up any lingering confusion.