[yorkiblue]

so a quick google search of the speed earth is orbiting the sun is 67,000 mph..add to this the sun is orbiting the galactic centre at 514,000 mph..so how is it possible that the north star remains fixed when we are moving at a total speed of 581,000 mph..

[juner]

The RE explanation is that the sun moves similarly to Polaris, (essentially being equal and canceling each other out) and that earth's movement does affect the "fixed" position of Polaris but it's too minuscule to notice.

Very convenient for RE, I agree...

[TotesNotReptilian]

so a quick google search of the speed earth is orbiting the sun is 67,000 mph..add to this the sun is orbiting the galactic centre at 514,000 mph..so how is it possible that the north star remains fixed when we are moving at a total speed of 581,000 mph..

Junker's explanation isn't quite correct. I'm honestly not sure if Polaris is moving along with us or not. It is relatively close to us, so it is probably orbiting the milky way at approximately the same rate as the sun.

Keep in mind, "relatively close" in this context is on the order of several hundred light years. Polaris is approximately 430 lightyears away from us. That's 2,500,000,000,000,000 miles. So let's assume the worst case scenario: Polaris is moving perpendicular to us at 1,000,000 mph. Surely, we would easily be able to see it move, right? Let's do the math:

At 1,000,000 mph Polaris will have moved 8,760,000,000 miles during a single year.

atan(8,760,000,000 miles / 2,500,000,000,000,000 miles) = 0.0002 degrees

That's tiny. At this rate, for Polaris to move 1 degree in the sky, it would take 5000 years. The vast distances between stars can be difficult to imagine. It should not be surprising at all that Polaris stays relatively fixed in the sky.

Very convenient for RE, I agree...

I'm not sure what you mean by "convient". It is indeed convenient for navigational purposes that there is a bright star very close to the north celestial pole. The south celestial pole has no such luck. (Although the very existence of the south celestial pole is hard evidence that the earth is NOT flat).

[yorkiblue]

all them numbers hurt my head. but thanks for the reply..researching polaris deeper there are indications it has moved slightly in the sky over the last few thousand years.so i guess that makes sense.

[TotesNotReptilian]

all them numbers hurt my head.

Me too. Too many zeroes. If you understand scientific notation, perhaps this will help:

Distance to Polaris = 2.5x10¹⁵ miles
Distance traveled by Polaris in one year (assuming 1 million mph) = 8.7x10⁹ miles

Also, atan is also commonly referred to as arctan or tan^-1.

Good luck!

[rabinoz]

all them numbers hurt my head.

Me too. Too many zeroes. If you understand scientific notation, perhaps this will help:

Distance to Polaris = 2.5x10¹⁵ miles
Distance traveled by Polaris in one year (assuming 1 million mph) = 8.7x10⁹ miles

Also, atan is also commonly referred to as arctan or tan^-1.

Good luck!

While we are on Polaris, it has not always been the Pole star - not even during well recorded history.

History of Polaris.
Polaris hasn’t always been the North Star and won’t remain the North Star forever. For example, a famous star called Thuban, in the constellation Draco the Dragon, was the North Star when the Egyptians built the pyramids.

But our present Polaris is a good North Star because it’s the sky’s 50th brightest star. So it’s noticeable in the sky. It served well as the North Star, for example, when the Europeans first sailed across the Atlantic over five centuries ago.

And Polaris will continue its reign as the North Star for many centuries to come. It will align most closely with the north celestial pole – the point in the sky directly above Earth’s north rotational axis – on March 24, 2100. The computational wizard Jean Meeus figures Polaris will be 27’09” (0.4525°) from the north celestial pole at that time (a little less than the angular diameter of the moon when at its farthest from Earth).

From: http://earthsky.org/brightest-stars/polaris-the-present-day-north-star

And

Past and future pole stars.
Indeed, Thuban at times made a better pole star than our modern Polaris. Various sources claim that Thuban almost exactly pinpointed the position of the north celestial pole in the year 2787 B.C.

Meanwhile, our modern Polaris – which many centuries ago was an ordinary star known by the name Phoenice – won’t match Thuban’s precision when it most closely aligns with the north celestial pole on March 24, 2100. Polaris will be 27’09” (0.4525°) from the north celestial pole at that time (a little less than the angular diameter of the moon when at its farthest from Earth), according to the computational wizard Jean Meeus.

The Northern Hemisphere also has had long stretches without a pole star. After the reign of Thuban but before that of Polaris, Kochab in the Little Dipper served as a rather poor pole star in 1100 BC. Kochab was only half again as close to the north celestial pole as it is today.

From Thuban past North Star