Julio A. Fernández is a planetary scientist recognized by his work on scattering and transport of planetesimals in the early solar system, Oort cloud formation, planet migration, and identi cation of the Kuiper belt as the source of Jupiter family comets. Fernandez was born and grew up in Montevideo, Uruguay. He got his degree in Astronmy at the Universidad de la Republica (Udelar), Uruguay, in 1974. Then he was visiting astronomer at the Madrid Observatory, Spain, Max-Planck Institut fur Aeronomie and Max-Planck Institut fur Kernphysik, Germany, and Visiting Professor at the Valongo Observatory, Federal University of Rio de Janeiro, Brazil. He returned to Uruguay in 1987, where he was appointed as Full Professor of the Department of Astronomy at the Udelar. Fernández was Dean of the Faculty of Sciences (2005-2010), President of Commission 20 of the International Astronomical Union (IAU) “Positions and Motions of Minor Planets, Comets and Satellites” (2006-2009), and he is currently member of the IAU Committee for Small Bodies Nomenclature. He is also member of the National
Academy of sciences of Uruguay, the Third World Academy of Sciences, and the Latin American Academy of Sciences.

Research Interests

Julio A. Fernández's research has fundamentally been related to accretion and scattering of planetesimals by the Jovian planets, dynamical evolution of comets and formation of the Oort cloud. Comets are considered to be the most primitive bodies of the solar system, the icy planetesimals that were left after the formation of the planets, so their study is of key importance to understand the accretion processes in the protoplanetary disk. As a sample of the most relevant results of his work it can be mentioned: (1) Jupiter family comets (i.e. comets in short-period orbits whose evolution is dominated by Jupiter's perturbations) may come from a -at that time (1980)- putative trans-neptunian belt, result that was conrmed several years later with the
discovery of the trans-neptunian objects. (2) Most Oort cloud comets may come from the Uranus-Neptune zone, from where they were scattered to near-parabolic orbits by the Jovian planets after their formation. (3) The original birthplaces of the Jovian planets were shown to be different from their current locations due to a substantial migration during their accretion process by the exchange of angular momentum between the accreting Jovian planets and the gravitationally scattered planetesimals located in the protoplanetary disk. This phenomenon has attracted a lot of attention in the last couple
of decades after the discovery of exoplanets very close to their central stars that probably migrated from larger distances. (5) The theory that the solar system formed within an open cluster, as most stars do, so the structure of the Oort comet cloud surrounding the solar system was shaped by the gravitational perturbations of other member stars of the primordial cluster.

Membership Type

International Member

Election Year


Primary Section

Section 16: Geophysics

Secondary Section

Section 12: Astronomy