Aten

noun

ˈä-tᵊn 

plural Atens

astronomy

: any of a class of asteroids having orbits that are mainly within the Earth's orbit but that may extend beyond it at their outermost point : an asteroid having an orbit with a semimajor axis of less than one astronomical unit

There are two families of asteroids with orbits that cross Earth's. Members of the Aten family spend most of their time inside our orbit, while Apollo objects are mostly beyond Earth, with only the innermost point of their orbit inside ours.

—Jeff Hecht and David L. Chandler, New Scientist, 22 Feb. 2003

compare amor sense 2, apollo

Word History

Etymology

after 2062 Aten, the first such asteroid to observed (1976), from Aten, disk of the sun in ancient Egypt (vocalization of Egyptian ỉtn)

First Known Use

1982, in the meaning defined above

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