Astronomers use physics, chemistry and mathematics to study the makeup of the universe. They discover facts about other astrophysical objects using telescopes on Earth and in space, radio, computers and the geology of Earth. Astronomers also use digital cameras and charge-couple devices in order to convert the data captured by telescopes into electrical signals for further study on computers.
Light is the primary subject astronomers study that gives them information about the universe. When light is traveling from an object moving away, it is red-shifted. When an object is traveling toward one, the light it reflects or emits is blue-shifted. By measuring the amount of these light-shifts, astronomers calculate the distance the light traveled and the object's position in space. Astronomers operate in the field, gathering meteorites and investigating collision sites for comet matter.
Astronomers are either researchers, teachers or both. In preparation for a career in astronomy, extensive physics and math classes are needed. Most important is a desire to know how the universe works and the patience to understand that it often takes decades and centuries to discover new phenomena. College is a requirement to land a job in astronomy. In fact, most astronomers have advanced degrees and experience in college laboratories.