Galaxies are huge groups of stars, gas, dust and space materials. These groups form when gas, dust and stars are pulled together by a magnetic core. Our galaxy, the Milky way, is a spiral galaxy. Elliptical Galaxies Elliptical galaxies have a spherical or elliptic shape, and maintain this shape as they move through space. They contain groups of old stars, and little bits of gas and dust.
Some elliptical galaxies resemble nebula, or large clouds of gas, because they are so old.
These galaxies are especially valuable, because their stars may have been created around the time of the Big Bang. They are often composed of very young stars, and contain a lot of gas and dust. It is possible for these galaxies, out of contact with other galaxies, to become spiral or elliptical galaxies, although this is rare. Certain galaxies are formed when two galaxies collide. These galaxies have a bulge in their center, surrounded by a spiraling of galaxy.