October has two full moons, and the first one took place on October 1, while the second one occurs on October 31 – Halloween. Because of time zone differences, in eastern Australia and New Zealand, this full moon falls on November 1. Thus, it is the first of two November 2020 full moons there.

Halloween is also the fourth and final cross-quarter day of 2020 – the spookiest of the four. It was previously known as All Hallows Eve and to us in North America as Halloween. The second of two full moons in one calendar month is widely known as the Blue Moon. Therefore, this Halloween we will have a Blue Moon, but there’s more! On this year’s Halloween, bright red Mars will appear close to the full moon in the sky. Now, it is past its nearest approach to Earth in 2 years.

Blue Moon. Red Mars. Doesn’t it sound spectacular?

However, the full moon won’t actually be blue in color, only in name.

It is definitely something that you don’t want to miss! The next full moon to fall on Halloween will take place on October 31, 2039. And red Mars being close is a rare occasion as well, especially since Mars is usually not bright when seen from Earth.

The moon will be completely visible, as seen from all over the world, on October 30 and 31, 2020.

From an astronomical aspect, though, full moon occurs as soon as the moon is directly opposite the sun (180 degrees from the sun in celestial length). This full moon moment arrives on October 31, at 14:49 UTC (9:49 a.m. EST, 8:49 a.m. CST, 7:49 a.m MDT, 6:49 a.m. PDT, 5:49 a.m. Alaskan Time and 4:49 a.m. Hawaiian Time).

This full moon is the most far and smallest full moon this year, and that is why it is also known as a micro-moon (252,380 miles or 406,166 km).

Seven lunar months before this Halloween full moon, the nearest and biggest full moon of the year occurred on April 8, 2020. In addition, exactly seven lunar months after this Blue Moon, we will have the closest and largest full moon in 2021, on May 26.

We can expect a new Blue Moon (second full moon in one calendar month) on August 31, 2023. This time around, though, it’s going to be a Blue Moon supermoon (the nearest and biggest full moon of 2023). This Blue Moon supermoon will be 222,043 miles or 357,344 km. away.

The interesting thing is that the moon phases recur every 19 years, on almost or exact same calendar dates. As we previously mentioned, the next full moon to fall on Halloween will be in October 2039.

This 19-year lunar period has 235 lunar months (235 returns to full moon) and just 228 calendar months. Since the number of full moons exceeds the number of calendar months, at least seven of the 228 calendar months would have two full moons (235-228 = 7 extra full moons).

To sum up: This month has two full moons, and the second one falls on October 31, 2020. Therefore, it is called a Blue Moon – the smallest full moon this year. Also, it is close to red Mars. Don’t miss it!