12 September 18

Today's tie choice was triggered by this curious description of an event on 12 September 1758: "French astronomer Charles Messier mistakenly identifies the Crab Nebula so begins his Messier Catalogue." I had to investigate that "mistake" . . . the explanation is that Messier was using his telescope to search the sky for the predicted return of Halley's Comet, and found a "new object" whose fuzzy appearance led him to classify it as a comet. After further observations, Messier could tell that the fuzzy object did not move like a comet, and so it became Object Number 1 in his catalog of new heavenly bodies. More advanced telescopes later revealed the spectacular, detailed composition of what we now call the Crab Nebula. My tie celebrates many planets and galaxies.