AstrochemistryIntroduction |
What is a galaxy? |
A galaxy is a huge system consisting of stars, planets, gas, dust, and lots of other interstellar media. The galaxy we live in is called the Milky Way. Galaxies have a lot of stars—the smallest have roughly ten million, while the largest have a hundred trillion! All of the “stuff” in a galaxy orbits around the center of mass of that galaxy.