A galaxy is held together by gravity. Share Print. Here's my short version. Our galaxy is called the Milky Way. Zoom In The structure of the Milky Way: A flattened disk with spiral arms (seen face-on, left, and edge-on, right), with a central bulge, a halo, and more than 150 globular clusters. A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems. Our galaxy, the Milky Way, also has a supermassive black hole in the middle. This image from the NASA/ESA Hubble Space Telescope shows the rich galaxy cluster Abell 3827. A galaxy is not the universe, which is much bigger and contains all the galaxies. How Big Is the Galaxy? The Samsung Galaxy S8 and LG G6 are pioneering a new trend for smartphones: big screens that sport extra-wide aspect ratios. The Milky Way is a huge city of stars, so big that even at the speed of light, it would take 100,000 years to travel across it. The Milky Way is our home galaxy, the spot where the Earth resides. How big "the galaxy" is depends on a whole lot more open questions. It’s by far the largest structure in our galaxy, and arguably defines how big the Milky Way truly is, but it's exceedingly dim or invisible to our eyes, so getting its size is hard. When we leave the solar system, we find our star and its planets are just one small part of the Milky Way galaxy. The Zharkov family—father, mother and two young sons—belong to the Dolgan community, one of the last indigenous peoples pursuing their traditional nomadic life in the extreme north of Siberia. It is thought that 200-400 billion stars are within the Milky Way. :) Log in to post comments; By CB (not verified) on 04 Jun 2012 #permalink. Ksenia Elyan; Russia, Estonia; 2018; 72 min; World Premiere; Luminous; Created with Sketch. It is about 12,000 light years across (1 light year = almost 5.878625 trillion miles). How big is the biggest galaxy, and how small is the smallest? Our galaxy is very big. When you look up at stars in the night sky, you’re seeing other stars in the Milky Way.