A galaxy is a group of billions of stars held together by gravity. Galaxies also contain interstallar gas and sust. The universe may have about 50 billion galaxies. The one we live in is called the Milky Way. The sun and stars we see at night are just a few of the 200 billion stars in the Milky Way. Light from a star along one edge of the galaxy would take about 100,000 years to reach the other edge. Astonomers measure the distance bettween stars and between galaxies in light-years. One light-year is the distance light travels in one year - about 5.9 trillion miles. ---- Put your problems into prospective!