Siwa
140 Siwa (A874 TB)
📋 A written introduction is coming — for now this page shows official values only.
Physical data
- Diameter
- 109.79 km
- Rotation period
- 34.445 hours
- Albedo
- 0.0676
- Absolute magnitude H
- 8.45 mag
- Spectral type (Tholen)
- P
- Spectral type (SMASS)
- Xc
Orbit
- Orbit class (JPL)
- MBA — Main-belt Asteroid
- Semi-major axis
- 2.73 AU
- Eccentricity
- 0.218
- Inclination
- 3.19°
- Perihelion distance
- 2.13 AU
- Aphelion distance
- 3.33 AU
- Orbital period
- 1,650 days
- Perihelion passage
- JD 2461635.297
- Earth MOID
- 1.12 AU
Earth approach
- Potentially hazardous (PHA)
- No
- Near-Earth object (NEO)
- No
In everyday life
- About 110 km across — 27.4% of the 400 km Seoul–Busan expressway.
- One orbit takes about 1,650 Earth days (about 4.5 years).
- Sunlight needs about 23 minutes to reach it on average (semi-major axis 2.7 AU) — versus about 8 min 19 s to Earth.
Worked out from this object's official values.