An Overview of Asteroids and Near-Earth Objects


An Overview of Asteroids and Near-Earth Objects


Michael Gaffey

About the Speaker

Dr. Michael Gaffey is a Chester Fritz Distinguished Professor in the Space Studies Department at UND. He joined Space Studies in 2001 from faculty position in the Earth and Environmental Sciences Department at Rensselaer Polytechnic Institute. Previously he had been a research faculty member at the University of Hawaii (Institute for Astronomy & Hawaii Institute of Geophysics). He obtained his BA (1968) and MS (1970) degrees from the University of Iowa (Geology, Astronomy) and his PhD (1974) from MIT (Earth and Planetary Sciences). Starting with his PhD thesis in the early 1970’s, Dr. Gaffey has focused on the development and application of remote sensing capabilities (visible and near-infrared spectroscopy) to the investigation of asteroids in order to better understand the early history of our solar system, the resource potential of these bodies, and the impact hazard that they present.



Asteroids are samples of the population of planetesimals which filled the early inner solar system and from which the terrestrial planets accreted. The asteroid fragments that fall to Earth as meteorites represent samples of at least 135 chemically distinct parent bodies. Following their formation, these parent bodies experienced a wide range of thermal histories from essentially unheated through complete melting. The meteorites are a very biased sample of main belt population, being dominated by parent bodies located near “escape hatches” (orbital resonances) in the main belt. The near-Earth asteroid / object (NEA, NEO) population suffers a similar but somewhat less severe bias. Care must be exercised in extrapolating the relative frequency of compositional and physical types among the meteorites to the NEO population. Understanding the suite of physical and chemical properties among the NEO population is critical to accessing the impact hazard and resource potential of these objects.


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Publication Date



Grand Forks, ND

An Overview of Asteroids and Near-Earth Objects