Michael Efroimsky (russian: Михаил Эфроимский) is an American

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...

of Russian origin. His research interests are in

celestial mechanics Celestial mechanics is the branch of astronomy that deals with the motions of objects in outer space. Historically, celestial mechanics applies principles of physics (classical mechanics) to astronomical objects, such as stars and planets, to ...

and relativity. He is working as a Research Scientist at the

US Naval Observatory United States Naval Observatory (USNO) is a scientific and military facility that produces geopositioning, navigation and timekeeping data for the United States Navy and the United States Department of Defense. Established in 1830 as the Depo ...

in Washington DC. Michael Efroimsky is a member of the

International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...

and the

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 ...

(AAS). In 2008 - 2009, he served as the Chair of the

Division on Dynamical Astronomy The Division on Dynamical Astronomy (DDA) is a branch of the American Astronomical Society that focuses on the advancement of all aspects of dynamical astronomy, including celestial mechanics, solar system dynamics, stellar dynamics, as well as the ...

of the AAS. With

Sergei Kopeikin Sergei Kopeikin (born April 10, 1956) is a USSR-born theoretical physicist and astronomer presently living and working in the United States, where he holds the position of Professor of Physics at the University of Missouri in Columbia, Missouri. ...

and George Kaplan, Michael Efroimsky co-authored a book on the relativistic

of the

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...

. With Benoit Noyelles, Julien Frouard and Valeri V. Makarov, Michael Efroimsky co-authored a theory explaining the origin of the present state of rotation of the planet

Mercury Mercury commonly refers to: * Mercury (planet), the nearest planet to the Sun * Mercury (element), a metallic chemical element with the symbol Hg * Mercury (mythology), a Roman god Mercury or The Mercury may also refer to: Companies * Merc ...

, a so-called 3:2 spin-orbit resonance. With Amirhossein Bagheri, Amir Khan, and other colleagues, Michael Efroimsky co-authored a theory explaining the origin and orbital evolution of Phobos and

Deimos Deimos, a Greek word for ''dread'', may refer to: * Deimos (deity), one of the sons of Ares and Aphrodite in Greek mythology * Deimos (moon), the smaller and outermost of Mars' two natural satellites * Elecnor Deimos, a Spanish aerospace company * ...

, the satellites of

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...

. According to this theory, Phobos and Deimos are remnants of a common progenitor, a larger protomoon destroyed by a collision with a planetesimal. Michael Efroimsky also published translations from classical Russian poetry.

Notes

External links

personal webpage
Year of birth missing (living people) Living people American astronomers {{US-astronomer-stub