Astronomers study infinity and beyond! Their work focuses on the universe including the sun, stars, galaxies, planets, and moons. Astronomers use physics and mathematics in their research, along with computer science. An undergraduate degree in physics with some astronomy courses is essential to prepare for graduate work in the field. Most astronomers work for universities as faculty members or in associated observatories. Others work for federal government agencies such as the Department of Defense and NASA. Do the names Galileo and Copernicus sound familiar?