Mercury retrograde

Mercury, from Liber astronomiae, 1550

Mercury, from Liber astronomiae, 1550

Ye gods!!

According to astrologers, anything bad which happens between September 17th and October 9th, is because Mercury has reversed the direction of it’s orbit around the Sun!

Yupe, dog ate your homework? Blame it on Mercury retrograde.

Your computer was infected by a virus? It’s Mercury retrograde.

Big fight with the spouse? You’ve got it – Mercury retrograde.

Over centuries, astrologers have been making a great living off Mercury retrograde.

I have no doubt that even in 2015, there will be suckers… eeerr…. sorry… believers in the deleterious effects of Mercury’s retrograde 🙂


Animation of Mercury’s and Earth’s revolution around the Sun

But what is Mercury retrograde?

The smallest planet in our Solar system, Mercury regularly undergoes what is known in astronomy as apparent retrograde motion.

In simple English, it just means that instead of moving in an anti-clockwise orbit around the Sun, Mercury appears to slow down and begins moving in a clockwise orbit around the Sun!!

Note the triple emphasis on “appears” 🙂


Well, the Earth rotates on an axis which runs from the North Pole to the South Pole.

If you were hovering directly above the North Pole in your space craft, you will see the Earth rotating in an anti-clockwise direction.

So, if you were standing on the Equator, the Sun, the stars and the planets seem to be moving from East to West.

But the Earth and all the other planets are also orbiting the Sun in an anti-clockwise direction.

The time taken for the orbits of the planet around the Sun are all different – about 365 days for Earth and about 88 days for Mercury.

Now if one takes the rotation of the Earth, the annual orbital periods of Earth and Mercury into consideration, there is a time period where an observer on Earth will see Mercury apparently slow down and begin to move backwards.

I know, it takes some thinking and much finger-twirling to figure this out but the Wikipedia entry on apparent retrograde motion does have a nice explanation for it.

What is less known is that virtual ALL celestial bodies exhibit retrograde motion. It is just that many of these celestial bodies move too slowly for us to detect.

Mars retrograde

Mars retrograde

The retrograde motion of Mercury is relative easy to detect because it is quite close to Earth and quite bright and thus quite visible.

Hopefully, by discussing such nonsensical codswallop using what we know today, we can dispel stupidity and ignorance to where it belongs – the past.

And oh, Mercury retrogrades about three or four times a year 🙂


Other links


2 comments for “Mercury retrograde

  1. Mercy
    September 23, 2015 at 10:55 pm

    Mercury retrograde? not a good time to make an important decision? What will happen to the life of the people that influenced by the belief like that? Malaysia universities have enrollment on September. If you have the belief like that, that means…..

    • moses
      September 23, 2015 at 11:01 pm

      Don’t forget the Super Blood Moon:)

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