Metis astronomical symbol.
Source: Original version is from Gould, B.A. 1852, On the Symbolic Notation of the Asteroids, Astron. J., 2, 80. via [1], SVG version is my. http://en.wiktionary.org/wiki/File:9_Metis_symbol.svg
Author: original is Benjamin Apthorp Gould, SVG version is User:Bryan Derksen