SOLAR SYSTEM

Detailed explanation-1: -A galaxy is a giant, spinning object made of gas, dust, and stars held together by gravity. Galaxies come in different shapes and sizes and can contain billions of stars. Most occur in groups that are also held together by gravity.

Detailed explanation-2: -A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems, all held together by gravity.

Detailed explanation-3: -Stars form in the densest regions of the interstellar medium, or ISM, called molecular clouds. The ISM is the name given to the gas and dust that exists between the stars within a galaxy. It is 99% gas and 1% dust, by mass. Properties of ISM gas in our region of the Milky Way Galaxy: 70% hydrogen.

Detailed explanation-4: -The Milky Way gets its name from a Greek myth about the goddess Hera who sprayed milk across the sky. In other parts of the world, our galaxy goes by other names. In China it’s called the “Silver River, ‘’ and in the Kalahari Desert in Southern Africa, it’s called the “Backbone of Night.”

Detailed explanation-5: -Because this grouping includes stars, it would be called a galaxy. Compare this to a nebula, which also incorporates gas and dust held together by gravity.