ABSTRACT
Our galaxy is an impressive cosmic sculpture, a swirling platter of matter 100,000 light-years across. But just like our sun is a typical, garden-variety example of the Milky Way’s 200 billion or so stars, the Milky Way itself is just another galaxy among others. Many, many others—recent findings suggest there are around 2 trillion galaxies in the observable universe. In other words, for every one of the myriad uncountable stars in our galaxy, there are 10 galaxies out there, each with billions of stars of their own. Galaxies come in many shapes, but some are more common than others. Most galaxies that have been observed are spiral galaxies, like the Milky Way. Elliptical galaxies tend to contain older stars, with few new ones being formed, and can be much larger than other types. Elliptical galaxies are likely formed from the mergers of other galaxies, including spirals.
