Editing 9 Metis (section)

==Characteristics==
[[file:9Metis (Lightcurve Inversion).png|thumb|[[Lightcurve]]-based 3D-model of Metis]]
Metis's direction of rotation is unknown at present, due to ambiguous data. Lightcurve analysis indicates that the Metidian pole points towards either [[ecliptic coordinate system|ecliptic coordinates]] (β, λ) = (23°, 181°) or (9°, 359°) with a 10° uncertainty.<ref name="Torppa03">J. Torppa et al., [http://www.rni.helsinki.fi/~mjk/thirty.pdf ''Shapes and rotational properties of thirty asteroids from photometric data''], Icarus Vol. 164, p. 346 (2003).</ref> The equivalent [[equatorial coordinate system|equatorial coordinates]] are (α, δ) = (12.7 h, 21°) or (23.7 h, 8°). This gives an [[axial tilt]] of 72° or 76°, respectively.{{Citation needed|date=June 2007}}

[[Hubble Space Telescope]] images<ref name="Hubble05">A. D. Storrs et al., ''A closer look at main-belt asteroids 1: WF/PC images'', Icarus Vol. 173, p. 409 (2005).</ref><ref name="Hubble99">[http://web.media.mit.edu/~win/hstpub.pdf Hubble Space Telescope observations] {{webarchive|url=https://web.archive.org/web/20081030022816/http://web.media.mit.edu/~win/hstpub.pdf |date=30 October 2008 }}</ref> and lightcurve analyses<ref name="Torppa03" /> are in agreement that Metis has an irregular elongated shape with one pointed and one broad end.<ref name="Torppa03" /><ref name="Hubble99" /> Radar observations suggest the presence of a significant flat area,<ref name="Mitchell95">D. L. Mitchell et al., ''Radar Observations of Asteroids 7 Iris, 9 Metis, 12 Victoria, 216 Kleopatra, and 654 Zelinda'', Icarus Vol. 118, p. 105 (1995).</ref> in agreement with the shape model from lightcurves.

The Metidian surface composition has been estimated as 30–40% metal-bearing [[olivine]] and 60–70% [[Nickel|Ni]]-[[Iron|Fe]] metal.<ref name="Kelley00" />

[[Light curve]] data on Metis led to an assumption that it could have a [[natural satellite|satellite]]. However, subsequent observations failed to confirm this.<ref>[http://www.bdl.fr/observateur/binast/binary_ast.php research at IMCCE] {{webarchive|url=https://web.archive.org/web/20020612093733/http://www.bdl.fr/observateur/binast/binary_ast.php |date=12 June 2002 }} (in French)</ref><ref>[http://www.johnstonsarchive.net/astro/asteroidmoonsq.html "other" reports of asteroid companions]</ref> Later searches with the [[Hubble Space Telescope]] in 1993 found no satellites.<ref name="Hubble99" />