Matija Cuk Wins Prestigious Urey Prize

By David Morrison, Director of the Carl Sagan Center

Matija CukSETI Institute scientist Matija Cuk has received the highest honor for a young planetary scientist from the American Astronomical Society. The Division for Planetary Sciences of the AAS has announced the award the 2014 Harold C. Urey Prize for outstanding achievement in planetary research to Matija Cuk. The award will be presented at the DPS meeting in November.

Matija is a specialist in planetary dynamics – the study of the effects of gravity on the motions of objects in the solar system. The AAS/DPS announcement of the prize noted that his broad-ranging research is significantly contributing to understanding the origin of the solar system’s current structure. His interests also span general aspects of planet and satellite formation. This research is driven by observations, primarily dynamical but also chemical and geophysical. He has applied his skills across a broad range of topics: the origins and evolutions of the Moon, binary asteroids, tidal evolution, orbital stability, rotational history and cratering.

Matija did his undergraduate work in astrophysics at the University of Belgrade in Serbia, and he received his Ph.D. in 2005 from Cornell University. His thesis developed an analysis of how planets capture Irregular satellites, and then investigated the effects of secular resonances on their orbits. This work has been described as a technical tour de force in celestial mechanics. During this same period he devised and convincingly demonstrated the existence of the BYORP mechanism in which thermal radiation forces affect the orbital and rotational histories of binary asteroids. Other researchers have since elaborated on this mechanism, as has Matija, working with collaborators, some of whom were initially skeptical of its effectiveness.

A crescent Moon glows above Earth's atmosphere in this image from the International Space Station. The entire lunar disk is visible because it's illuminated by earthshine, which is sunlight reflected off of Earth's dayside, Credit: NASA

Recently Matija has focused on the Earth-Moon system, including the evolution of the Moon’s orbit and the origin of the lunar impact cataclysm (the “late heavy bombardment”), and on aspects of the dynamics of unstable bodies in the solar system. He found a significant flaw in the interpretation of the lunar cratering record. His study of the number density of the craters on the Orientale ejecta blanket (the youngest impact basin) indicated that fresh (class 1) craters date back to the lunar impact cataclysm. His research undercut the widely accepted assumption that the cataclysm was caused by asteroids from the main asteroid belt between Mars and Jupiter. Matija’s result challenged the status quo and solicited some strong responses, but no one identified any conceptual flaws in his arguments. New data from the Lunar Reconnaissance Orbiter support his interpretation.

Matija’s work on the origin of the Moon sought to address the observed isotopic similarity between the Earth and Moon. He identified the angular momentum constraint as a possible pathway to reconciliation between the geochemical data and giant impact hypothesis: if the early Earth-Moon system had much higher angular momentum than present day, then alternate style impact events may derive the Moon primarily from Earth’s mantle. He defined the tidal parameters that led to the largest transfer of angular momentum from the Earth-Moon system to the Earth-Sun system. Matija’s result is a major contribution to planetary science, opening new directions for understanding the origin and early evolution of the Earth-Moon system. 

The SETI Institute and its Carl Sagan Center for the Study of Life in the Universe are proud to congratulate our colleague Matija Cuk, who is clearly an outstanding young researcher worthy of being recognized by the Harold C. Urey Prize.