Once in a Blue Moon

Lots of stuff happening on (and around) the same day.

Sharad Purnima

Today it’s Sharad Purnima, a Hindu tradition. It is a harvest festival that is celebrated on the full moon day of the lunar month of Ashvin. It’s also called Kojagiri Purnima. It’s the birthday of Devi Lakshmi, and she is worshipped on this day. Also worshipped are Indra, and Shiva and Parvati. Lots of worshipping going on among Hindus.

Jack-o’-lantern (Click to embiggen)

Today it’s Halloween, a Christian tradition. The all-knowing Wiki says, “Halloween is the evening before the Christian holy days of All Hallows’ Day on 1 November and All Souls’ Day on 2 November, thus giving the holiday on 31 October the full name of All Hallows’ Eve (meaning the evening before All Hallows’ Day). … These three days are collectively called Allhallowtide and are a time for honoring the saints and praying for the recently departed souls who have yet to reach Heaven.”

Today we will also have a blue moon. And talking of time, today is the last day of Daylight Saving Time. Tomorrow morning at 2 AM, the clock will be set back to 1 AM. That will bring us back to Standard Time. I think this shifting of clocks business is insanely stupid. It makes no sense to keep shifting between DST and ST. Just stop this crap, people.

Blue Moon

Here’s more about this Halloween’s blue moon:

Saturday night’s Blue Moon will light up the sky Oct. 31, the first full moon visible across the country on Halloween in 76 years. The last time a full moon visible in every time zone fell on Halloween was in 1944. The next will come in 2039.

The Blue Moon will reach its peak at 10:49 a.m. ET but will appear full the day before and the day after Oct. 31.

While called a “Blue Moon,” the Halloween moon won’t actually be a different color. According to the Farmers Almanac, the name comes from the full moon’s timing and not its color. Whenever two full moons appear in a single month – something that happens on an average of every 2 ½ to 3 years – the second full moon is known as a “Blue Moon.” [Source.]

People all over the world name the full moons. The first full moon following the September equinox is called the Harvest moon (that’s the one we had Oct 1st.). The next full moon, the Beaver moon, will be on Nov 30th, and then the last full moon of 2020 will be on Dec 29th. That is called the Cold moon. 

If you want to see the full moon from the comfort of your home, click on the image below. 

It will take you to the Virstual Telescope Project

“The Virtual Telescope Project is an advanced service provided by the Bellatrix Astronomical Observatory in Italy and managed by Dr. Gianluca Masi, PhD.  It consists in several, robotic telescopes, remotely accessible in real-time over the Internet, both for research and fun, available for all.  Despite the technologically advanced instrumentation, the system is very easy to use.”

Life on Earth

We seem to have a special affection for the moon. And with good reason. There is a theory that without the moon, life may not have appeared on earth. Tidal pools may have been where the earliest living things evolved. Here’s a bit about the moon from the wiki page:

The Moon is thought to have formed about 4.51 billion years ago, not long after Earth. The most widely accepted explanation is that the Moon formed from the debris left over after a giant impact between Earth and a hypothetical Mars-sized body called Theia. New research of Moon rocks, although not rejecting the Theia hypothesis, suggests that the Moon may be older than previously thought.

The Moon is in synchronous rotation with Earth, and thus always shows the same side to Earth, the near side. Because of libration, slightly more than half (about 59%) of the total lunar surface can be viewed from Earth. The near side is marked by dark volcanic maria that fill the spaces between the bright ancient crustal highlands and the prominent impact craters. After the Sun, the Moon is the second-brightest celestial object regularly visible in Earth’s sky. Its surface is actually dark, although compared to the night sky it appears very bright, with a reflectance just slightly higher than that of worn asphalt. Its gravitational influence produces the ocean tides, body tides, and the slight lengthening of the day.

The Moon’s average orbital distance is 384,402 km (238,856 mi), or 1.28 light-seconds. This is about thirty times the diameter of Earth. The Moon’s apparent size in the sky is almost the same as that of the Sun, since the star is about 400 times the lunar distance and diameter. Therefore, the Moon covers the Sun nearly precisely during a total solar eclipse. This matching of apparent visual size will not continue in the far future because the Moon’s distance from Earth is gradually increasing.

Earth-Moon System

Here’s a schematic of the earth-moon system. Note that the center of mass of the system is inside the earth since the earth is so much more massive compared to the moon. 

The distance between the earth and the moon is pretty large.You can fit all the solar system planets in the space between the earth and the moon. Here’s a model with distance and size to scale:

Now you know that Hubert Dreyfus was right when he said that “climbing a tree will get you closer to the moon but will not actually get you there.”

Pale Blue Dot

So far twelve people–all Americans–have walked on the moon. The first man to step on the lunar surface was Neil Armstrong. He got to be that partly because NASA administration recognized that he did not have a large ego. (Trump would not have qualified.) I am sure that there are people alive today who will staff a permanent base on the moon — and they will number in the hundreds. Humans have a way of colonizing distant places.

The Pale Blue Dot will not be the only place where people will live. Let’s listen to Carl Sagan’s brilliant thought about it:

That’s but a very small excerpt from Sagan’s book. Here’s another video. About the video:

Some time before he died in 1996, Carl Sagan recorded a partial audio version of his 1994 book “Pale Blue Dot”. This video represents an “chapter one” of sorts, the beginning of an unauthorized video series based on Carl Sagan’s “Pale Blue Dot” audio book, combined with a soundtrack and appropriate images intended to recall the feel of classic BBC/PBS documentary series, such as “Ascent of Man” and “Cosmos”.

Highly recommended. Alright, now for a song that has the moon in it. It’s by Sarah Brightman. Son of the Moon. 

The song is about a legend. A gypsy woman in a forest asks the moon to find her a gypsy husband. The moon agrees but on the condition that the first born will belong to the moon. So the gypsy woman finds a gypsy man. A son is born but instead of his skin being cinnamon color, it is white. It was the son of the moon. The gypsy man thinks that the woman had cheated. He kills the woman and leaves the son in the forest. So when the son is happy, the moon is full; and when the little boy cries, the moon turns itself into a cradle and rocks him to sleep.

Have a good weekend.

Author: Atanu Dey


5 thoughts on “Once in a Blue Moon”

  1. Did you know that distance between earth and sun is 108 times the diameter of sun?
    Also, that distance between earth and moon is 108 times the diameter of moon?
    Also, that diameter of the sun is 108 times the diameter of earth?


    1. Certainly there are some interesting relations between sizes and distances. But nothing too astonishing, really. Also, one should be careful about assigning significance to them. BTW, the distance to the sun from earth is ~1000 times the diameter of the sun — which is quite a lot different from 108. Look it up.


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