140 Siwa
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| Discovery | |
|---|---|
| Discovered by: | Johann Palisa |
| Discovery date: | October 13, 1874 |
| Alternative names: | |
| Minor planet category: | Main belt |
| Orbital characteristics | |
| Epoch December 31, 2006 (JD 2454100.5) | |
| Aphelion distance: | 497.275 Gm (3.324 AU) |
| Perihelion distance: | 320.360 Gm (2.141 AU) |
| Semi-major axis: | 408.817 Gm (2.733 AU) |
| Eccentricity: | 0.216 |
| Orbital period: | 1650.076 d (4.52 a) |
| Avg. orbital speed: | 17.80 km/s |
| Mean anomaly: | 156.165° |
| Inclination: | 3.187° |
| Longitude of ascending node: | 107.292° |
| Argument of perihelion: | 197.230° |
| Physical characteristics | |
| Dimensions: | 109.8 km |
| Mass: | 1.4×1018 kg |
| Mean density: | ? g/cm³ |
| Equatorial surface gravity: | 0.0307 m/s² |
| Escape velocity: | 0.0580 km/s |
| Rotation period: | ? d |
| Albedo: | ? |
| Temperature: | ~168 K |
| Spectral type: | ? |
| Absolute magnitude: | 8.34 |
140 Siwa is a large and dark main belt asteroid. It has a composition of a P (or possibly C-type) asteroid. It was discovered by J. Palisa on October 13, 1874 and named after Siwa, the Slavic goddess of fertility. Siwa has a very flat lightcurve, indicating a spherical body.
The Rosetta comet probe was to visit Siwa on its way to comet 46P/Wirtanen in July, 2008. However, the mission was rerouted to comet 67P/Churyumov-Gerasimenko and the flyby had to be abandoned.
| Minor planets | ||
|---|---|---|
| Previous minor planet | 140 Siwa | Next minor planet |
| List of asteroids | ||
Vulcanoids · Near-Earth asteroids · Main belt · Jupiter Trojans · Centaurs · Damocloids · Comets · Trans-Neptunians (Kuiper belt • Scattered disc • Oort cloud)
For other objects and regions, see Asteroid groups and families, Binary asteroids, Asteroid moons and the Solar System.
For a complete listing, see List of asteroids. See also Pronunciation of asteroid names and Meanings of asteroid names.
