The hubble ultra deep field helps to illustrate too: http://upload.wikimedia.org/wikipedi...deep_field.jpg

Each object in the pic, as faint and small as it may be, is a galaxy. And remember this picture is just a small section of the known universe, the Hubble could have been pointed in another direction and there are more galaxies beyond all you can see in there.

To believe no earth like planets or different planets that harbor life exist out there, one must have a very wrong idea about the size of a galaxy.