Astronomy Bio...Ernst Öpik

Jay Bitterman

Ernst Julius Öpik was born in Port Kunda, a coastal village in Estonia on October 23,1893. He went to school at Tallinn High School and Moscow Imperial University and completed his education at the Tartu State University. In 1916 he began working at the Tashkent Observatory in Uzbekistan. In 1918 he moved to the Observatory at the University of Moscow, where he worked as an Assistant and Instructor. He was a Lecturer at Turkistan University from 1920 to 1921. From 1921-1944 he was an Associate Professor and a lecturer in astronomy at Tartu University. Besides being a research associate and visiting lecturer, from 1930 to 1934, at Harvard College Observatory in the United States, Öpik remained at Tartu University until 1944. Because he formerly volunteered in the White Russian army and vehemently opposed the Bolshevik Revolution and the Soviet occupation of Estonia, he emigrated to Hamburg, He was then appointed Research Associate at the University of Hamburg and in 1945 he became Professor and Estonian Rector at the German Baltic University.

In 1948 Öpik moved to Northern Ireland, was appointed as a research associate and eventually became director of the Armagh Observatory where he remained until 1981. Since 1956 Öpik divided his time between Northern Ireland and the United States at the University of Maryland as a visiting professor (and later associate professor). In 1968 he was appointed to the Chair of Physics and Astronomy. In 1975 he received the gold medal of the Royal Astronomical Society

His early research was devoted to the study of meteors and he is the originator of the "double count" method for counting meteors in which two astronomers scan simultaneously.

He was one of the most outstanding astrophysicists of his time who possessed a wide-ranging interest in the physical sciences. He founded the meteor research group at Harvard that contributed to our knowledge of the minor bodies of the Solar System. His statistical studies of Earth-crossing comets and asteroids have contributed a fundamental understanding of the motions of these objects and how they impact Earth. He predicted the cratering on Mars that was dramatically confirmed by planetary probes. A minor planet Öpik was named after him in recognition of his work. Öpik was extremely productive in his research and was often controversial in his opinions. From 1950 to 1981 he published many of his papers, which he edited, in the Irish Astronomical Journal. His theory relating to surface events of meteors upon entering the Earth's atmosphere at high speed were extremely important in the development of heat shields and other protective devices that made it possible for spacecraft to withstand friction and the resulting intense heat upon re-entry. Much of his work was aimed at the analysis of comets that orbit our Sun. He assumed that the orbit of some of these comets could be as far away as one light year. Additionally, he made studies of double stars, cosmic radiation and stellar photometry.

Some of his other pioneering discoveries were:

  • In 1915, the first computation of the density of a degenerate body, namely the white dwarf 40 Eri B.

  • In 1922, the first accurate determination of the distance of an extragalactic object (Andromeda Nebula)

  • In 1932, the prediction of the existence of a cloud of cometary bodies encircling the Solar System that was later known as the ``Ort Cloud''.

  • In 1938, the first composite theoretical models of dwarf stars like the Sun, which showed how they evolve into giants.

  • And in 1952, a new theory of the origin of the Ice Ages.

Öpik died in Northern Ireland on September 10,1985.