Friday the 13th - on Friday, September 13 - will have a little extra mischief when a rare full Harvest Moon will be viewable to some in the USA, according to the Farmers' Almanac. This lunar event is so rare that it hasn't happened for almost 20 years.
The Harvest Moon this week is the ninth Full Moon of the year and one of the most chilling spectacles of astronomy.
Technically, a full moon occurs at a specific moment.
You won't want to miss this Micro Harvest Moon.
What makes the Harvest Moon unique is that rather than rising its normal average of 50 minutes later each day, the moon rises at almost the same time each night leading up to when it's full. But in the days leading up to the Harvest Moon, this interval shortens to around 27 minutes on average, meaning there is more light available to farmers after sunset. Yet, you can still spot the moon throughout the night.
According to the Farmers' Almanac, "It has been calculated that to have a full moon occur on the 13th day of a particular month, and for that day to be a Friday, it is (on average) a once in 20-year occurrence".
Unless cloud cover blocks the view, the full moon is the easiest celestial event to observe. This is because the moon is also nearing its apogee-the point in its almost month-long elliptical orbit at which it s furthest away from Earth.
However, depending on where you live in Canada, the moon will reach it's the fullest point at different times throughout the night.
"The Moon was more than 30,000 miles closer and was accordingly branded a "Supermoon".
The Harvest Moon will also peak during a so-called Micromoon when the lunar orb appears up to 14 percent smaller.