Ismene
190 Ismene (A878 SA)
📋 A written introduction is coming — for now this page shows official values only.
Physical data
- Diameter
- 159 km
- Rotation period
- 6.521 hours
- Albedo
- 0.066
- Absolute magnitude H
- 7.88 mag
- Spectral type (Tholen)
- P
- Spectral type (SMASS)
- X
Orbit
- Orbit class (JPL)
- OMB — Outer Main-belt Asteroid
- Semi-major axis
- 4 AU
- Eccentricity
- 0.168
- Inclination
- 6.17°
- Perihelion distance
- 3.32 AU
- Aphelion distance
- 4.67 AU
- Orbital period
- 2,920 days
- Perihelion passage
- JD 2462333.392
- Earth MOID
- 2.35 AU
Earth approach
- Potentially hazardous (PHA)
- No
- Near-Earth object (NEO)
- No
In everyday life
- About 159 km across — 39.8% of the 400 km Seoul–Busan expressway.
- One orbit takes about 2,920 Earth days (about 8 years).
- Sunlight needs about 33 minutes to reach it on average (semi-major axis 4 AU) — versus about 8 min 19 s to Earth.
Worked out from this object's official values.