Spark and Perl go looking
That star is not moving.
Everything else has gone round, and that one has stayed put.
That is Polaris, the North Star.
The whole sky turns around it, all night long.
Then it must be the brightest star in the sky.
Not even close.
Dozens of stars outshine it. It is famous for standing still, not for shining.
So a star can matter without being bright.
Exactly.
It sits almost straight above the Earth’s North Pole, so the Earth turns underneath it and the star hardly moves at all.
Is it in the same place for everybody?
The further north you live, the higher it stands.
At the North Pole it is straight overhead. At the middle of the world it sits right on the horizon.
And if you live south of the middle?
Then you never see it at all. It stays below the horizon.
And the southern sky has no star at its pole — only a patch with nothing much in it.
Then how do people down there find south?
They use the Southern Cross.
Follow its long bar about four and a half times its own length, and you reach the empty spot the whole southern sky turns around.
So the north has a star, and the south has an empty spot.
And each sky turns around its own pole.
Only from the northern half of the world.
There, find the Plough: the two stars at the end of its bowl point straight at Polaris.
From the southern half, look for the Southern Cross instead — it points at the south’s own empty pole.
Where to find Polaris, and when
Where the map is clear, this climbs high in the sky. The darker the shading, the lower it stays. Where the map is black, it never comes up. No shading at all: where you live makes no difference.
What do I need to see Polaris?
Your own eyes are enough.
It is the one star that hardly moves all night.
Binoculars with 10× magnification, resting on a fence or a wall, show more.
A 150 mm telescope shows it as a point of light — with a faint little companion star right beside it.
Space
Eyes, binoculars, or telescope?
Read on
Go and look