What does the iron stake and the Southern Cross mean?

I noticed something in Dacha, how clear the sky looks at night in our part of the world.

You can see almost all the stars with the naked eye.

In Moscow, even on the most cloudless days, you cannot see such a clear sky. The lights of the city interfere with this clarity.

Here, I can see the big bear right away, a huge scoop shaped, its shape is immediately recognisable among the other stars.

How was it to find the north pole star? (Polaris, the Iron Pile!)

The polar star would be 5 or 7 lengths ahead of the two stars on the edge of the big bear constellation, the scoop, right?

OK, I've got it. It's in the tail of the little dipper.

It doesn't shine that brightly, but you can still see it if you look carefully.

The pole star is higher up here than it is in Turkey. I suppose that makes sense. The further north you go on the Earth's surface, the higher up the pole star will appear.

To see the pole star at the pole, you have to raise your head exactly upwards, because the pole star coincides with the axis of rotation of the earth.

Isn't it interesting that there is a star on the axis of rotation?

And it hasn't moved for centuries.

In fact, the pole star is not exactly on the axis of rotation, it seems to be rotating in a very small circular orbit as the earth rotates. But its shift from the axis of rotation is so small that it can be said to be exactly in the north.

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Once upon a time, sailors used to use the pole star to find their direction.

Of course, the compass was invented later. Sailors found flour with a compass for many years.

And now, thanks to the satellites placed in orbit, with the GPS system (Global Positioning System, Global Positioning System), neither the polar star nor the compass is no longer needed.

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I just had a question. Since the pole star points north, it should only be visible in the northern hemisphere.

I wonder what sailors used to do in the southern hemisphere?

I mean, how did they navigate before the compass was known and naturally before the GPS system?

Is there such a star as the South Pole Star?

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I did some research and found out that, unfortunately, there is no star that can be seen with the naked eye in the south like the North Pole Star.

In fact, there is a star called Sigma Octantis, or Polaris Australis. But this star is 25 times dimmer than the north pole star. 

We can hardly find the north pole star in the north, imagine that it is a star 25 times dimmer. It is also not connected to a constellation like ours, which is very easily visible in the shape of a scoop.

So for sailors, Sigma Octantis is not a star they can make much use of.

It seems that sailors in the south are not as lucky as those in the north.

There are no obvious stars in the southern sky in the direction of the Earth's axis of rotation, but there is another constellation in the southern hemisphere that is useful for navigation. 

This constellation is called the Southern Cross (Crux).

Although it is not exactly to the south, and a simple association with Sigma Octantis in the south cannot be made, this constellation of Crux is immediately noticeable in the sky, and experienced sailors can navigate with this constellation even if they are not standing in a fixed place.

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We see this constellation, which they call the Southern Cross, on the flags of several countries.

For example, the stars on the flag of Australia are the stars of the Southern Cross constellation.

The same constellation also appears on the flags of New Zealand and Western Samoa.

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By the way, it would be impossible to close this subject without mentioning one more thing: The Iron Pile, which we call the pole star, will not always be exactly north.

Because our earth does not rotate steadily around its current axis of rotation. It makes a certain wobbling movement.

Even if this wobble is very heavy, one day Vega will be our north pole star instead of Polaris.

Of course, don't ask what this wobble is all about, I'm talking about the kind of wobble that makes a spinning top shake its head slightly as it spins around. The reasons are various, even the moon has an effect on this wobble.

Anyway, this is not such a noticeable wobble, it has a period of 25,800 years. In other words, one round of nodding can be done in a very long time.

According to calculations, the star Vega will become our north pole star in 13 thousand years.

So it is certain that you and I will not see this change.

Let me end this article by saying "May you have plenty of stars".

Love and respect to everyone from Moscow.