The Local Group is part of the Local Supercluster, which has a diameter of about 100 million light-years. No one knows whether the universe is finite or infinite in size. Studies of the sky indicate that there are at least 100 billion galaxies in the observable universe. Measurements show that the most distant galaxies observed to date are about 12 billion to 16 billion light-years from the earth. They are observed in every direction across the sky.
Astronomers determine the distance to a faraway object by measuring the object's red shift.
The observer sees light from a receding object at wavelengths longer than those that would be seen by an observer who was moving with the object. The observed change in wavelength is the object's red shift. The amount of red shift depends upon the speed at which the object recedes from the observer. The larger the red shift is, the more rapidly the object is moving away. Among the most distant objects ever observed are tremendously bright objects called quasars.