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What are the Average Distances Between Stars and Between Galaxies?

-- Niall | January 19, 2021

Question:

Hi there

I worked out, very roughly, that stars in the Milky Way are about 5-10 Light years apart(if evenly distributed) and as stars are only about a few light minute sin diameter then Galaxy is very sparse. Also I work out that the Galaxys in the Universe are(very roughly) 200b to 5m Light years apart. So relatively closely packed.

Are these two items about right?
ps It occurred to me that the observable Universe is only 140,000 times the diameter of the Milky Way which I thought was a small number!

Thanks – great site!

-- Niall

Answer:

Your estimate for the average distance between stars is reasonable. Your estimate for the average distance between galaxies is also a good estimate, which agrees with the information given on Physics Stack Exchange to a similar question. In fact, the answer provided on Physics Stack Exchange provides some nice background information that you might find interesting.

-- Jeff Mangum

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