Do galaxies have orbit ?
112797
Galaxies are constantly colliding with eachother because of gravitational attraction.  In fact, most galaxies are in clusters of galaxies that stay in clusters because of a mutual gravitational attraction,(including our own milky way), so in a sense, these clusters of galaxies have somewhat of a jumbled orbit around eachother untill they collide and form new galaxies.  These orbits are much different than planetary orbits in that they are not as uniform.
138345
Just about all astronomers agree that at the center of our Milky Way Galaxy (and probably at the center of most other galaxies) lies a supermassive black hole. It probably has a mass at least 2-million times that of our Sun, and is approximately 96-million miles in diameter.\n\nThese figures come from careful observation and measurment of the motions of other objects near the galactic center.\n\nThis page has more info, plus a photo ---\nhttp://antwrp.gsfc.nasa.gov/apod/ap021018.html
979991
A simple answer and that is because of the gravitational force.\nIt also has no orbit.
749553
The Universe is expanding, but individual galaxies are not expanding.  So the stars within a galaxy aren't getting farther apart from each other.  Similarly, our solar system is not expanding (many people get confused about all that).\n\nIn fact, even galaxies within a cluster of galaxies aren't moving apart from each other - for example, the Milky Way galaxy and the Andromeda galaxy are moving *towards* each other, and will collide in a few billion years.  It's the clusters of galaxies that are moving away from each other.\n\nEven though the galaxy itself isn't expanding, the stars are all moving relative to each other.  They all rotate the center of the galaxy, and they also have random motions.  So (as other people above have said) the constellations as we see them today will change - their shapes will become more and more distorted over time.  Here's a neat website which shows what the Big Dipper will look like in the future: http://www.fourmilab.ch/yoursky/help/proper.html
1057373
When we look toward the galactic center we see a long, thin strip. This suggests a disk seen edge-on, rather than a ellipsoid or another shape. We can also detect the bulge at the center. Since we see spiral galaxies which are disks with central bulges, this is a bit of a tipoff. \n\nWhen we measure velocities of stars and gas in our galaxy, we see an overall rotational motion greater than random motions. This is another characteristic of a spiral.
222144
Two objects will orbit one another indefinately unless disturbed.  The man made satellites that return to earth orbit to closely and are so small, atmospheric drag and solar wind eventually cause their orbits to decay.\n\nThe moon is large enough are far enough out, these factors don't come into play.  The primary force now is tidal friction, which causes the orbit to slow, and therefore expand, by a fractional amount each year.  \n\nDon't worry about losing the moon, though.  The sun will expand into a red giant, swallowing both earth and moon long before this happens.
563730
Galaxies are clusters of stars and its planetary systems found in groups across the universe. List of Galaxies can be found in link below. \n\nThey are really far... measured in light years and the distance is increasing as per our expanding universe.
763882
A galaxy is a swirling collection of stars. our own Milky Way galaxy contains hundreds of billions of stars, of which our sun is only one amongst these billions and billions.\n\nA solar system is just a single sun that has planets revolving around it. A galaxy is made up of billions of such suns. And some scientists believe that as many as 25% of the stars could have planets. That means billions and billions of solar systems in our own galaxy.\n\nHere'a a picture of our closest neighbor, the Andromeda galaxy. It has close to one-trillion stars.\n\nHope this heolps. Cheers\n\nhttp://en.wikipedia.org/wiki/Andromeda_Galaxy
821714
Galaxies come in a variety of shapes.  Ours is a spiral, but only about 25% of galaxies are spirals.  There are also barred spirals (about 20%), which tend to be a bit smaller than normal spirals.  There are ellipticals (about 50%), a category with the widest range of sizes, from the dwarf ellipticals that accompany the Andromeda spiral to giants with up to a trillion stars.  These, although classed as ellipticals, are usually spherical in shape.  There are also irregular galaxies, and rare ones like Seyferts and ringtails.\nAs to why, the best we can say at the moment is that this is the consequence of their evolution and gravitational interaction with other galaxies, including collisions and mergers.
964940
Galaxies are huge clusters of billions of stars.  Smaller hunks of stars are called "clusters"  -- but once they get really _REALLY_ big, they're called galaxies. \n\nSolar systems are systems of planets and other hunks of rock orbiting a SINGLE STAR...   so, the Earth and the other planets are part of OUR solar system,  orbiting the sun.  Other suns have OTHER solar systems where DIFFERENT planets are orbiting. \n\nThe speed of light is REALLY REALLY FAST. \n\nIf you turn on a light on the moon, no one on earth will see the light for almost two seconds because it took the light that long to get here. \n\nBut the speed of light is _SO FAST_ that even going from New York to Las Angeles, all the way across the United States it only takes about two one-hundredths of a second to get there (0.016 seconds) \n\nThis shows two things, the moon is a LONG ways away,and light is VERY VERY FAST.  The speed of light is 186000 (one hundred and eighty six thousand) miles per second.  A rifle bullet travels only around two to three thousand miles per hour.  So, light is two hundred thousand  times faster than a speeding bullet.  Really REALLY fast.
1091211
not for billions of years. And actually there will be almost no impact on either galaxy, other than one of them, or both, being mis-shapen by one another's gravity pull. Actually it is possible for galaxies to collide and not have one star hit another because galaxies are mostly empty space believe it or not. But the person above is also right, the gravitational tug on eachother could spark new star forming regions. even if we live that long, and say the sun is still around, meaning the planets are too, then our solar system will most likely not be affected. Also to add, the universe is expanding, but on the larger scale. Galaxies normally live in clusters and within clusters galaxies can collide and merge, but on the bigger scale the galaxy clusters are moving away from eachother.
319780
Yes, the Sun revolves around it's own axis, just like the Earth.  It spins around every 27 days.  It just doesn't ORBIT anything.\n\nedit: actually, it orbits the galaxy.  Takes a few hundred million years.
67361
At least 100 billion galaxies are known to exist in the Universe. Our galaxy is a spiral one, so in terms of structure it consists of galactic core and several spiral arms. In terms of composition it includes stars, planets (made from regular matter, including atoms of all naturally occurring elements and ions), galactic gas and dust (made from regular matter, mostly hydrogen and helium as far as the gas goes, and hydrogen, carbon, silicon, oxygen and some other elements as far as the dust goes), dark matter and dark energy (there is little known about the last two).
237923
Yes, there are clusters of galaxies. As was stated, the one with the Milky Way galaxy is called the local cluster. Other clusters close by are the Virgo cluster and the Coma cluster; named for the constellation where you can see these galaxies. As you go to larger scales, there are also superclusters of galaxies.
384805
The First law of Kepler is: \nPlanets move along elliptical orbits with the Sun\nat a focus.\n\nSo, all i can say is that the sun is relatively stagnant in our immediate universe.\nThe earth rotates along an elliptic orbit around the sun.\nThe moon rotates along an elliptic orbit around the earth.\n\nWell, all "movements" are relative to some reference point.
279767
As far as we can tell, space is infinitely big.  It's rare for galaxies to collide.  It does happen, however.  Below is a link to an article about a recently seen collision.  Keep in mind, however, that because of the distances involved these galaxies actually collided millions of years ago, and the light is just reaching us now.
138404
Often when people are told that galaxies are receding from us, they assume that means we are at the center of the Universe.  However, remember that the Universe is homogeneous and isotropic.  No matter where one is, it looks the same in all directions.  Thus, all galaxies\nsee all other galaxies receding from them.  Hubble's relationship is compatible with a Copernican view of the Universe: Our position is not a special one.\n\nSo where is the center?  *There isn't one*.  Although apparently nonsensical, consider the same question about the *surface* of a sphere (note the *surface*).  Where's the center of a sphere's surface?  Of course, there isn't one.  One cannot point to any point on a sphere's surface and say that, here is the center.  Similarly, because the Universe is homogeneous and isotropic, all we can say is\nthat, in the past, galaxies were closer together.  We cannot say that galaxies started expanding from any particular point.