Here are some examples of bad astronomy that you might want to include in your next book:

1: General Custer's mistaking Venus for a rocket on the morning of 27 November 1868.

2: Frances Rolleston's brilliant deduction that the unusual names of the stars Rotanev and Sualocin in Delphinus were derived from the Chaldean rotaneb and the Arabic al scalodin, both meaning "swift running water." Imagine her embarrassment when she found out (if she ever did) that they were actually named in the nineteenth century by Giuseppe Piazzi, Director of the Palermo Observatory in Sicily, in honour of his assistant Niccolo Cacciatore, whose name in Latin was Nicolaus Venator (that's Sualocin Rotanev backwards)!

3: Sidus Ludovicianum, or Ludwig's Star, the planet that wasn't. On 2 December 1722, Johann Georg Liebknecht, professor of theology and mathematics at the University of Giesen, observed the star Tycho 3850-257-1, between Alcor and Mizar in Ursa Major, and came to the amazing conclusion that it was a planet, even though it was in the exact same position as it had been when Benedetto Castelli observed it in 1617! Liebknecht named his new "planet" in honour of the Landgrave Ludwig V of Hesse-Darmstadt. The name survived: the professor's reputation didn't.

__________________
- Learn a lot teaching others.