Jaan Einasto


Jaan Einasto is an Estonian astrophysicist and one of the discoverers of the large-scale structure of the Universe.

Family and early life

Born Jaan Eisenschmidt in Tartu, the name "Einasto" is an anagram of "Estonia".
Einasto married and had 3 children, 2 daughters and the youngest, a son. His daughter, Maret, is also an astrophysicist, who collaborates with her father.

Education and career

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 Head of the Department of Cosmology; from 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.
  • 1947 Tartu Secondary School No. 1
  • 1952 University of Tartu
  • 1955 Cand.Sc. in physics and mathematics
  • 1972 D.Sc. in physics and mathematics
  • 1992 Professor
Since 1991 he is member of Academia Europaea. Since 1994 he is member of the Royal Astronomical Society.
In 1974, in a seminal work with Kaasik and Saar at the Tartu Observatory, Einasto argued that "it is necessary to adopt an alternative hypothesis: that the clusters of galaxies are stabilised by hidden matter." This was a key paper in recognizing that a hidden matter, i.e., dark matter, could explain observational anomalies in astronomy.
Einasto showed in 1977 at a Symposium in Tallinn that the universe has a cell structure, in which the observed matter surrounds huge empty voids.

Awards, honours, legacy

The asteroid 11577 Einasto, discovered in 1994, is named in his honour.
The Einasto Supercluster, a galaxy supercluster discovered in 2024, is named in his honour.