9 Metis
|
|
| Discovery A (http://cfa-www.harvard.edu/iau/lists/NumberedMPs.html) | |
|---|---|
| Discoverer | Andrew Graham |
| Discovery date | April 25, 1848 |
| Alternate designations | 1974 QU2 B (http://cfa-www.harvard.edu/iau/MPDes.html) |
| Category | Main belt |
| Orbital elements C (http://asteroid.lowell.edu/) Epoch July 14, 2004 (JD 2453200.5) | |
| Eccentricity (e) | 0.122 |
| Semi-major axis (a) | 357.052 Gm (2.387 AU) |
| Perihelion (q) | 313.556 Gm (2.096 AU) |
| Aphelion (Q) | 400.548 Gm (2.678 AU) |
| Orbital period (P) | 1346.815 d (3.69 a) |
| Mean orbital speed | 19.28 km/s |
| Inclination (i) | 5.576° |
| Longitude of the ascending node (Ω) | 68.982° |
| Argument of perihelion (ω) | 5.489° |
| Mean anomaly (M) | 274.183° |
| Physical characteristics | |
| Dimensions | 235×165 km [1] (http://web.media.mit.edu/~win/hstpub.pdf) km |
| Mass | 4.6×1018 kg |
| Density | 2 ? g/cm³ |
| Surface gravity | 0.036 m/s² |
| Escape velocity | 0.081 km/s |
| Rotation period | 0.2116 d 2 (http://www.psi.edu/pds/archive/lc.html) |
| Spectral class | S-type asteroid 3 (http://spiff.rit.edu/richmond/parallax/phot/LCSUMPUB.TXT) |
| Absolute magnitude | 6.28 |
| Albedo | 0.160 3 (http://spiff.rit.edu/richmond/parallax/phot/LCSUMPUB.TXT) |
| Mean surface temperature | ~185 K |
9 Metis (mee'-tis) is one of the largest Main belt asteroids. It is composed of silicates and metallic nickel-iron.
Metis was discovered by A. Graham on April 25, 1848; his only asteroid discovery. It is also the only asteroid to have been discovered from Ireland. Its name comes from the mythological Metis, a Titaness, daughter of Tethys and Oceanus (and thus an Oceanid), who was the first wife of Zeus and the mother of Athena. Zeus devoured her lest she bear a child more powerful than he.
Light curve data on Metis led to an assumption that it could have a satellite. However, subsequent observations failed to confirm this. [2] (http://www.bdl.fr/observateur/binast/binary_ast.php) [3] (http://www.johnstonsarchive.net/astro/asteroidmoonsq.html) Metis was later observed with the Hubble Space Telescope in 1993, which was able to resolve the irregular shape of the asteroid, but no satellites were detected. [4] (http://web.media.mit.edu/~win/hstpub.pdf)
Metis has been observed occulting a star no less than 5 times.
Metis is also the name of a satellite of Jupiter.
External links
- "Notice of discovery of Metis", MNRAS 8 (1848) 146 (http://adsabs.harvard.edu//full/seri/MNRAS/0008//0000146.000.html)
- Irish Astronomical History: Markree Castle Observatory and The Discovery of the Asteroid Metis (http://www.eaas.co.uk/news/metis.html)
| The minor planets |
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| (For other objects and regions, see: Binary asteroids, Asteroid moons and the Solar system) |
| (For a complete listing, see: List of asteroids. For pronunciation, see: Pronunciation of asteroid names.) |