Galaxies

stars in that region are hidden by dark dust particles.

The difference is in the shape, as can be guessed by the name.

"And God made two great lights; the greater light to rule the day, and the lesser light to rule the night: he made the stars also."-Genesis 1:16

Earth's solar system is in the milky way which includes sagittarius as a satellite galaxy and locales may overlap thus the answer is sometimes

The question of planet habitability [See Link] is based on early F or G, to mid-K type stars. This equates to approximately 15% of all stars in main sequence.

However, it has been estimated that 50 % of these will be binary star systems, which in most cases would not be stable enough to offer any chance of life. However a study of Alpha Centauri, suggested that binaries need not be discounted in the search for habitable planets.

So about 7.5% of all stars could be suitable for planet habitability,

Saying there are 400 billion stars in our Galaxy, means around 30 billion stars could be suitable.

Canis Major Dwarf Galaxy. If you meant what's the closest spiral galaxy, then the answer is the Triangulum Galaxy.

Our own galaxy, the Milky Way, and our closest neighboring galaxy, Andromeda, are both spiral galaxies.

The Sun is "really" the closest star at 150,000,000 km (93,000,000 miles)

Proxima Centauri is the closest star to us, at a distance of approximately 4.2 light years.
(Proxima is Latin for "next to" or "nearest to")

Alpha Centauri is the closest star system to us at a distance of approximately 4.3 light years

The Centauri system is a triple star system Centauri A and B have a mean separation of 11 AU's and are similar in size and temp to the Sun.

Centauri C is a red dwarf it can not be seen with the unaided eye and was not discovered until 1918

See related link for more information.

Stars, dust, gas, black holes, dark matter...By far the most significant component, in terms of mass, is dark matter, making up about 80-90% of a galaxy's mass.

I think it's currently impossible to do that - specifically, to measure the distances of ALL the galaxies. There are just too many Astronomers might take a small section of the sky - say, a square degree or even a fraction thereof, analyze the galaxies in such a section, and extrapolate. As to the measurement itself, there are different methods; the Wikipedia article on "cosmic distance ladder" can give you a general idea. In summary, the farthest galaxies are simply measured by their redshift. That is to say, the farther they are, the faster they move away from us; and this can be measured using the Doppler effect.

They are simply called "galaxies which are part of a cluster".

The distribution of metals (In astronomy, that is any element other that hydrogen and helium) is reliant of the population stars. (See related question)

Metal rich stars, population I stars, are the latest "breed" of stars, whereas population III stars are the oldest and are classed as metal free stars.

So the furthest galaxies are likely to be formed from the initial gases from the big bang and will be metal free stars,

Excellent question. Too bad that we don't have a clue as to what is likely to happen that far into the future.

"Science" has made many fascinating discoveries, but the fundamental truth is that there will ALWAYS be more to learn - and we are so new to this game that that we sometimes arrogantly believe that we have made all of the "important" discoveries. Mankind has barely stepped out of the cradle, and already we pretend to know what happened at the dawn of the universe, or how the universe may ultimately evolve. We dd not.

Any answer that I give here in WikiAnswers is based on our CURRENT understanding of the universe, and with complete awareness that the universe is not only stranger than we imagine, it is stranger than we CAN imagine. We know so little about what can or might happen, that a prediction 100 billion years into the future is entirely meaningless.

The red end of the spectrum.

How fast are you going?

The Voyager probes started out pretty near the center and are just now, almost 40 years later, reaching what we think might be the boundary of the solar system. So, travelling at the fastest speed we've ever been able to send a probe away from the Sun, 80-90 years to cross it sounds about right.

Hubble discovered other galaxies than our own. His work lead to the idea that these galaxies are generally moving away from our own Milky Way. Further, logical thinkers considered that the universe itself is expanding. And if the universe is expanding, it must at some point have been "compressed" with all the matter closer together. This is the source of the idea we call the Big Bang.

A "guest" star is the name for the original star, before it exploded as a Supernova. Because the Supernova is the explosion and has no real physical relation to the Star, it is termed "guest" star.

First, the center of a galaxy is not a "bright light". It's a mathematical point. This is a technical quibble, and it is true that the centers of spiral galaxies (like the Milky Way) tend to be brighter than the rest of the disk due to the density of the stars there.

The reason we don't see the center of our own galaxy as a particularly bright patch is because we don't see by radio waves. In the radio spectrum, the center of the galaxy is quite bright. However, we see by visible light, and there's a lot of dust and gas between us and the center of the galaxy, which blocks out most of the wavelengths we can see.

When we say "bigger" here, we could be talking about the volume of space the objects take up, or the number of stars involved. In either case, it's tough sledding to make comparisons. In looking at the volume of space taken up by galactic clusters, we see galaxies bigger and smaller than our own Milky Way clustered together. Additionally, we can look at the sum of the volumes of the individual galaxies, or the volume of space that is "under control" of the gravity binding the galaxies in the cluster. In the former case, several tens the volume might be involved. In the latter, 106 to 109 times the volume might be too small as the distances between galaxies, even in a galactic cluster, is enormous. From 3 to 5 times or several tens of times the number of stars could be in a galactic cluster when compared to our Milky Way. We're still finding galactic clusters, and then categorizing them and cataloging them. Making comparisons is still a large challenge.

Not quite sure what you mean with "solar system of your galaxy". Mars is the fourth planet from the Sun. Mars's semi-major axis (in a sense, the average distance from the Sun) is 228 million kilometers, or 1.52 AU.

Satellite galaxies are typically small galaxies orbiting a larger galaxy. In our case, the Large and Small Magellanic Clouds are dwarf galaxies just beyond our Milky Way, but their velocity is high enough they are probably not satellite galaxies. Our sister galaxy, Andromeda, is orbited by about 14 dwarf galaxies.

As of November 2009, astronomers had listed 3,648 known comets (580 unclassified). This is a small fraction of the number that could exist, which could be as high as a trillion or more. Most will never come into proximity of the Sun, trapped in orbits well beyond the planets of the solar system.