Jaan Einasto (born 23 February 1929) is an eminent Estonian astrophysicist and one of the discoverers of Dark Matter and of the cellular structure of the Universe.
Born in Tartu, he attended the University of Tartu, where he received the Ph.D. equivalent in 1955 and a senior research doctorate in 1972. From 1952, he has worked as a scientist at the Tartu Observatory (1977-1998 Head of the Department of Cosmology; in 1992-1995, he was Professor of Cosmology at the University of Tartu. For a long time, he was Head of the Division of Astronomy and Physics of the Estonian Academy of Sciences in Tallinn. Einasto is a member of the Academia Europaea, the European Astronomical Society and the Royal Astronomical Society; he has received three Estonian National Science Awards.
Einasto has attracted the attention of the international scientific community as well as of the general public with his work on the structural formation and evolution of the Universe, especially as one of the discoverers of Dark Matter and as the discoverer of the cellular structure of the Universe.