This is a two-part question about stars and galaxies. :)?

Question

1. What is the average distance between two stars in a galaxy?

2. What is the average distance between two galaxies in the universe?

And...can we only measure this in light years?

Best answer gets 12 points...2 for posting, and 10 for the winner...lol hehe. :)

Answer 1

1) I'm assuming you mean the distance between two neighbouring stars that aren't binary or twin suns.  In this case, it would depend upon the size of the two stars, in terms of mass.

2) A few million light years.  Again, the distance would depend on the size of the galaxies.

Answer 2

Distance between stars is of the order of parsecs.

Galaxies, several hundred kiloparsecs.

And we can measure things in any length unit. But for astronomy light years and Parsecs are more convenient because they are very big.

Answer 3

I'm not sure about the "average", but our neighbor stars are generally 5-20 light years away, and our neighbor galaxies are ~2.5-5 million light years away.

We can measure this in any units we want, but light years are convenient because they are so big.

1 light year equals 9.46 x 10^15 meters.

Answer 4

we have other methods of measurement then light years.

Answer 5

this is hard to answer.

in some respects it's like asking, "How many cigarettes does the average person smoke?"

to which, in the US the answer may be 3.

on the other hand, if you asked only smokers, 20 would be closer.

our sun is unusual, in that it's in a relatively isolated part of the galaxy.

in more densly packed sections, the distance between stars would be measured in fractions of light years.

in fact, when you consider that a large percentage of stars are binaries, they're usually fairly close.

the other half of your question is just as hard, in that there are areas within the universe that are more, and less, densly populated.

in fact, i read within the week that there are 2 small galaxies that are currently in the process of colliding with ours.

that is, our galaxy is swallowing them up -- ours being much larger.

finally, as to units, 12,000,000,000,000,000,000 is considerably less useful than a few light years.

it's easier to distinguish between 25,000 light years and 2,000,000 light years than it is between 12,000,000,000,000,000,000 and 650,000,000,000,000,000,000 of anything.

Answer 6

There is no real average, but the closest star is to us (other than the Sun) is Proxima Centauri which is 4.22 light years to us, and the nearest galaxy is the Canis Major Dwarf Galaxy which is filled with red giant stars and is 25,000 LYs from our solar system. It was discovered in 2003.

You can measure these distances in whatever measurement of distance you want, but light years are probably the only way we can even hope comprehend the distances with our comparatively feeble minds.

Answer 7

1. Hard to say with certainty. Our nearest stellar neighbor (Proxima Centuri) is 4 light years, but that's very close by cosmic standards. Probably 10 or more would be more common. But it all depends on location. Starts near a galactic center would probably be closer together than out by an arm (like we are).

2. Same thing with galaxies. We're a million light years from Andromeda, but it's hard to give an average. Some galaxies are locked together (and collisions are not uncommon). Some are just bunched together in groups, groups are bound into clusters, and clusters can form superclusters. So anywhere from a few hundred thousand to a few million light years.

You can measure it with any distance mark you like, but light years are a good unit of measurement for this sort of thing, like measuring distance on Earth in miles or kilometers instead of feet or inches. I can never remember how big a parsec is, myself.

Answer 8

To add to the earlier responses, a parsec is 3.26 light years and thus we measure large distances in kilo- or megaparsecs.  For example, the isophotal Holmberg radius of the Milky Way's galactic disk is about 25 kiloparsecs.  For those who are interested, we define a parsec as that distance from which 1 astronomical unit, the average distance between the Sun and Earth, subtends 1 arcsecond of angular displacement.  Precise measurement of the Hubble parameter has made it convenient to express the distance of remote stars and galaxies in terms of their redshifts.  I hope that this has helped to amplify, and clarify, earlier responses.

Answer 9

go to this website, it is truely amazing.

The scale of the Universe.

Answer 10

I do not think you will get an answer on this one, because 1, Galaxies come in all sorts of sizes depending upon age and other factors, so there is no such thing as your average galaxy, 2 nobody knows the size of the Universe, and because of local irregularities observed in space, clusters and super-clusters of Galaxies are observed. Again any average is impossible to obtain as we have no basis on which to determine what the universe contains. There is no such thing as your average universe.

You may as well say 42. Also you can use whatever measurement unit you like but Light Years is generally used because it makes the units sufficiently large enough to handle easily.

Answer 11

In the disk, the average distance between stars is about 5 light years. If you assume 100 billion galaxies in a universe 13.7 billion light years in radius, you come up with about 3 million light years between galaxies.

You can measure these distances in furlongs, if you like. Astronomers mostly use parsecs, which are about 3.26 light years.