Blue Moon To Appear In S’pore’s Sky On 31 Oct; Next One Will Be 19 Years Later

Our natural satellite seems to be taking centrestage in lots of events in the coming months.

Apart from the fast-approaching Mid Autumn Festival, where the Moon serves as namesake for its signature dish, there is also Halloween.

The line between the living and the dead blurs again after the hell gates in Taoist folklore shut tight. People dress up spooky and mutilate decorate pumpkins, tinging the fear of the unknown with a sense of humour.

This year, our perpetual Celestial pearl decides to join in on the fun. In a rare occasion, the Moon will be gracing us with its full presence not once, but twice this month – with the second time falling squarely on Halloween.

Our annual spookfest is about to be extra special this year.

Once in a Blue Moon

On 31 Oct 2020, a Blue Moon watches as people go about trick or treatin’ (remember to keep your distance and sanitize the candies!).

A full moon qualifies as a Blue Moon when it’s the second one we see in a month (can someone make a rap out of this line).

The first one is expected to occur on the first day of Oct during Mid Autumn Festival. It will be an adorable Micro moon or Minimoon – a result of the Moon being at its farthest from Earth.

Alternatively, according to the Maine Farmers’ Almanac, when an astronomical season gets four full moons, the third one will be classified as a Blue Moon. In a single astronomical season, there are usually only three seasonal full moons.

By this definition, a Maine Farmers’ Blue Moon will occur on 22 Aug next year.

But it just lacks the flair of a Blue Moon on a Halloween, you know?

The Colour of Blue Moon

Despite its name, a Blue Moon is technically not blue.

However, the Moon could appear in shades of blue depending on the density of airborne smoke particles and dust.

It requires the air to be dominated by particles that are slightly wider than the wavelength of red light.

Normally, only forest fires and volcano eruptions are capable of producing the ideal clouds of ashes and dusts. The large particles scatter blue light, giving the Moon a cold tint.

In short, it takes relatively severe air pollution to turn the Moon (and its observers) blue. Better not, then.

Catch This Extra Treat on Halloween

The last time we had two full moons in a month was 19 years ago in 2001. The next one likely won’t happen for another 19 years until 2039.

So don your moon-gazing gears and haunting costumes, scale these spots we picked out just for you, and catch this extra treat on Halloween.

Here’s how a Blue Moon looks like:

Eh no sorry. This is the correct one:

Or maybe not. Remember, it depends on the atmosphere condition.