1900-1992

Dutch Astronomer

Jan Oort is popularly known for his description of the Oort Cloud that now bears his name. This cloud is located far outside of our solar system and is the source of the comets that orbit our sun. However, among professional astronomers, Oort is best known for his many discoveries concerning the structure of the Milky Way and other galaxies.

Oort was born in the Netherlands in 1900. During his lifetime he saw our view of the cosmos transformed from a single galaxy to an entire universe filled with galaxies. Many of his discoveries drastically changed our perceptions of our home galaxy, the Milky Way.

Oort's first major discovery came in 1927. His analysis of the motions of stars in our galaxy provided support for Bertil Lindblad's 1926 theory that our galaxy was rotating. Oort showed that the motion of different streams of stars...