Hi, I'm Shannon Silverman, astrophysicist at the Clay center.

And welcome to Almost Heavens.

Here in West Virginia, we're just about halfway between the North Pole and the equator.

That means we are in the perfect spot to view everything the northern skies have to offer.

And even a little of the southern skies, too.

During the summer, one of the most famous asterisms unofficial constellations is easily visibl and prominent in the night sky.

The Big Dipper the Big Dipper, made up of seven stars, is an incredibl recognizable asterism and often many people's introduction to navigating the night sky.

This asterism is seen and recognized all around the Northern Hemisphere and throughout history, even if what exactly it is a spoon of, how about a herd of caribou varies.

In addition to being easy to find, The Big Dipper is a helpful asterism when it comes to finding other objects.

One of those is also a quite famous star.

Though often difficult to find on its own, Polaris, the North Star players can be most easily found by looking for the Big Dipper and using the first two stars of the Cup, Dubay and Merak, as pointers, and following an imaginary lin with a small arc toward Polaris.

Polaris is not difficult to see, as it's bright enough to be visibl even with some light pollution, but without a guide, it can be tough to find, since it kind of looks like any other star.

But Polaris is not just any other star.

It's an unusual type of sta in itself, a yellow supergiant with two smaller companion stars.

So what we see as Polaris i actually three stars together.

It's also nearly directly over Earth's north pole.

So if you draw an imaginary line from the north Pole into space, it would poin almost perfectly toward Polaris.

If you were standing on the North Pole, Polaris would be almost directly overhead and the entire sky would spin around it.

This is why Polaris is called the North Star.

But Polaris is not the only North Star we've ever had.

The Earth as it rotates, it also processes.

This means that the direction the North Pole points makes little circles.

You've probably seen this effect yourself if you've ever spun a top.

This precession means the Earth's pole points to different stars, or even know stars at different points in time, causing our North Star to change as years pass.

The cycle completes and repeats every 26,000 years or so.

Two other previous and futur North stars can also be easily seen in the summer night sky.

One is Vega, the second brightest star of the Northern hemisphere.

It was the North Star about 12,000 years ago, and it will be again in about 12,000 years, though much less nicely aligned with the North Pole than Polaris is.

And more recent.

North Star is Theban, which is the pole star about 5000 years ago, and it was the most perfectly aligned of any North stars, at approximately 0.1 degrees from the pole.

For reference, Polaris is a little under one degree.

However, and is faint, so seeing it is a challenge in areas of light pollution.

Thank you for joining.

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Until next time.