You may have heard the term "galaxy" before. Galaxies are bodies which contain billions or maybe trillions of stars. They
come in many different kinds ranging from spiral, elliptical, lenticular, and irregular.
The galaxy we live in is known as the Milky Way Galaxy. The Milky Way is a spiral galaxy. Spiral galaxies are composed of
a long disc with two spiral arms coming out from each side. The spirals are probably caused by the gravitational pull from
Another shape a galaxy takes on is an elliptical form. These galaxies are known as elliptical galaxies. They are shaped as
flat circles. These galaxies consist of primarily old stars because of the limited space where billions of stars call home.
If you see a spiral galaxy with no spirals, it is a lenticular galaxy. They were spiral galaxies which stopped forming when
all the interstellar matter was used up. All other shapes that galaxies take on classify themselves as irregular galaxies.
They get a different shape when the force of gravity from other galaxies distort their image.
The Milky Way Galaxy, and other galaxies, have different parts. Our galaxy, for example, has a halo, nuclear bulge, or galactic
center, and the disk. The halo is an irregular sphere which contains many old stars. The nuclear bulge is the center
of the galaxy that sticks out.