25143 Itokawa
Asteroid· orbits the Sun
Itokawa is a small, peanut-shaped stony asteroid — a rubble pile of loosely bound fragments — sampled by Japan's Hayabusa in 2005, the first asteroid sample returned to Earth.
Open in 3D viewSee 25143 Itokawa in the live, interactive 3D map
Key facts
Radius
0.165 km
Distance from Sun
1.32 AU
Orbital period
556.5 days
Eccentricity
0.2802
Rotation
12.13 hours
Science
Physical
- Mean radius
- 0.165 km
- Mass
- 3.15 × 10¹⁰ kg · 0.000000000000429 Moon masses
- Density
- 1,672 kg/m³ · 1.7× water
- Rotation period
- 12.13 hours
Orbital
- Semi-major axis
- 1.32 AU
- Eccentricity
- 0.2802
- Inclination
- 1.62 °
- Orbital period
- 556.5 days
- Perihelion
- 0.953 AU
- Aphelion
- 1.7 AU
- Mean orbital velocity
- 25.9 km/s
Discovery
- Discovered
- September 26, 1998
- Discoverer
- the LINEAR survey
Composition
- Make-up
- An S-type rubble pile of silicate rock fragments with little internal cohesion.
Radiation & temperature
- Insolation
- 0.57 S⊕ · 57% of the sunlight Earth receives
- Geometric albedo
- 0.29
- Equilibrium temperature
- 222 K (-51 °C)
Discovery & history
- Discovered
- September 26, 1998
- By
- the LINEAR survey
- Method
- Photographic plates
- Name
- The Japanese rocketry pioneer Hideo Itokawa, father of Japan's space programme.
Itokawa is a tiny, elongated near-Earth asteroid found in 1998. A loosely-bound 'rubble pile' rather than a solid rock, it became the target of Japan's Hayabusa mission, which in 2005 became the first spacecraft to land on an asteroid and, in 2010, the first to return a sample of one to Earth.
- 2005HayabusaSample return
First mission to land on an asteroid and return a sample of one to Earth (2010).
Images
Images from open archives · credit shown per image