How often does a Blue Moon land on Halloween, you may ask?
Depends. It could be November 1 for you, while time zones to your West are still trick-or-treating. Back in the 20th and 21st centuries, the USA saw eight Halloween Blue Moons: 1906 1925 1944 2020 2039 2058 2077 & 2096.
@neiltyson Dammit Neil! Can you just leave anything to wonder???
@neiltyson Are there any cool science facts about the 26th of February