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The branch of astronomy that deals with the composition and structure of the planets of the solar system and with the relationships, similarities, and differences between them.

plan′e·to·log′i·cal (plăn′ĭ-tl-ŏj′ĭ-kəl) adj.
plan′e·tol′o·gist n.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Astronomy) astronomy someone who studies or specializes in planetology
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
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References in periodicals archive ?
"I am his Imperial Majesty's Planetologist," he whispered, "planetary ecologist for Arrakis.
Very soon he became known as a serious physicist, and also as an outstanding planetologist. The young scientist had taken a keen interest in the fashionable problem of the origin of stellar energy, but he solved this problem more generally, encompassing not only stars, but also planets and their satellites.
* A planetologist is a scientist who studies planets and their moons.
Clark Chapman, a planetologist at the Planetary Science Institute in Tucson, Arizona, says that more research is needed on cosmic collisions.
"To the working planetologist, his most important tool is human beings," his father said.
Caltech planetologist Andrew Ingersoll argues that Uranus and Neptune are at one end of a meteorological spectrum defined by the amount of thermal energy available to planets to drive turbulence in their atmospheres.
Planetologists at the University of ME-nster (Germany) have now been able to show, for the first time, that water came to Earth with the formation of the Moon some 4.4 billion years ago.