H. Jay Melosh (June 23, 1947 – September 11, 2020) was an American

geophysicist Geophysics () is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. The term ''geophysics'' som ...

specialising in impact cratering. He earned a degree in physics from Princeton University and a doctoral degree in physics and geology from Caltech in 1972. His PhD thesis concerned quarks. Melosh's research interests include impact craters, planetary tectonics, and the physics of

earthquakes An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...

and landslides. His recent research includes studies of the giant impact origin of the moon, the Chicxulub impact that is thought to have extinguished most dinosaurs, and studies of ejection of rocks from their parent bodies. He was active in astrobiological studies that relate chiefly to the exchange of

microorganisms A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...

between the terrestrial planets (a process known as panspermia or transpermia). Melosh was a member of the American Geophysical Union, Geological Society of America, Meteoritical Society,

American Astronomical Society The American Astronomical Society (AAS, sometimes spoken as "double-A-S") is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC. The primary objective of the AAS is to promote the adv ...

(Division of Planetary Sciences,) and the

American Association for the Advancement of Science The American Association for the Advancement of Science (AAAS) is an American international non-profit organization with the stated goals of promoting cooperation among scientists, defending scientific freedom, encouraging scientific respons ...

. He was the recipient of the

Barringer Medal The Barringer Medal recognizes outstanding work in the field of impact cratering and/or work that has led to a better understanding of impact phenomena. The Barringer Medal and Award were established to honor the memory of D. Moreau Barringer Sr. ...

of the Meteoritical Society for his work on the physics of impact, and of the

G. K. Gilbert Award The G. K. Gilbert Award is presented annually by the Planetary Geology Division of the Geological Society of America for outstanding contributions to the solution of fundamental problems in planetary geology in the broadest sense, which includes ge ...

from the Geological Society of America. He was elected to the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...

in 2003.

Awards and honors

* Asteroid

8216 Melosh 8 (eight) is the natural number following 7 and preceding 9. In mathematics 8 is: * a composite number, its proper divisors being , , and . It is twice 4 or four times 2. * a power of two, being 2 (two cubed), and is the first number of t ...

is named in his honor. * The American Geophysical Union 2008 Harry H. Hess Medal - for “outstanding achievements in research in the constitution and evolution of Earth and sister planets.”

Publications

* * ''Planetary Surface Processes'', Cambridge University Press, 2011, ()

References

External links

Homepage of H. Jay Melosh
{{DEFAULTSORT:Melosh, H. Jay American geophysicists Members of the United States National Academy of Sciences 1947 births 2020 deaths Planetary scientists American Astronomical Society Writers from Paterson, New Jersey Scientists from New Jersey Barringer Medal winners