Galaxies

A galaxy is a massive, gravitationally bound system consisting of stars, stellar remnants, an interstellar medium of gas, dust and dark matter. In the Universe there are numerous types of galaxies such as spiral, lenticular, elliptical or irregular. The best known galaxy is the Milky Way containing from 200 to 400 billion stars. Our solar system is located in the outer reaches of the Milky Way.

The entire Universe includes billions of galaxies that form clusters and superclusters of galaxies. Most of them are still unexplored.