Industries & Professions /
Astronomers study the universe and its celestial bodies by collecting and analyzing data. They also compute positions of stars and planets and calculate orbits of comets, asteroids, and artificial satellites. They strive to explain how the universe came to exist, how elements formed, why galaxies look the way they do, and whether there is other life in the universe. Astronomers make statistical studies of stars and galaxies and prepare mathematical tables giving positions of the sun, moon, planets, and stars at a given time. They study the size and shape of the earth and the properties of its upper atmosphere through observation and through data collected by spacecraft and earth satellites. There are approximately 2,700 astronomers employed in the United States.