Though the full moon in the photo above is red, a "blue moon" is happening Saturday, October 31, which just happens to be Halloween. The pictured moon was above the Spokane, Washington, skyline, and was red because of forest fire smoke October 1st. The Halloween full moon will be a normal white and will be visible most of the night in the Western Montana skies.

Usually, you have one full moon a month. However, the lunar cycle (from full to new moon) takes fewer days than the length of our regular months. So, occasionally, we get two full moons in a month. That's happening Saturday, October 31. The second moon of the month is called a "blue" moon - hence, the phrase "Once in a blue moon" for something that happens rarely. And this is the only Blue Moon of 2020. How rare for a Halloween blue moon? That last one was in 2001 and happens about every 19 years. The skies have been clear in the Bitterroot Valley this week, so our view will be good.

The October 1st full moon was the "Harvest Moon." This blue moon is named the "Hunters Moon" (hunting for trick or treat candy, maybe?) It rises in the East and sets in West, as always, and instead of being a Super Moon, when its orbit brings it closer to Earth, it's a Micro Moon, when the opposite happens.

So, gaze at the moon on Halloween and, if you see a woman with a pointy hat riding a broomstick, you've probably have had a bit too much hard cider.