9 Metis
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| Discovery | |
|---|---|
| Discoverer | Andrew Graham |
| Discovery Date | April 25, 1848 |
| Alternate Designations | 1974 QU2 |
| Category | Main belt |
| Orbital Elements 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] 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 |
| Spectral Class | S-type asteroid 3 |
| Absolute Magnitude | 6.28 |
| Albedo | 0.160 3 |
| Mean Surface Temperature | ~244 K |
9 Metis ("MEE tiss") 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] [3] 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]
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
- Irish Astronomical History: Markree Castle Observatory and The Discovery of the Asteroid Metis
| The Minor Planets |
| Vulcanoids | Main belt | Groups and Families | Near-Earth objects | Jupiter Trojans |
| Centaurs | Trans-Neptunians | Damocloids | Comets | Kuiper Belt | Oort Cloud |
| (For other objects and regions, see: Binary asteroids, Asteroid moons and the Solar system) |
| (For a complete listing, see: List of asteroids) |
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