Aster › Space program › Comet Halley
Comet Halley
Position on the route: 22/45 · level needed 520 · journey (Mk0 engine) 36.3 h
By the numbers
| Nucleus | 15 × 8 km |
|---|---|
| Orbit | 76 years |
| Last perihelion | 1986 (next 2061) |
| Albedo | 4 %, darker than coal |
The story
Humanity’s most famous comet, recorded since 240 BC. In 1705 Edmond Halley showed that the comets of 1531, 1607 and 1682 were the same body and predicted its return in 1758; he was proved right.
In 1986 five probes (Giotto, Vega 1 and 2, Suisei, Sakigake) went to meet it; Giotto came within 600 km of the nucleus and showed a surface darker than coal, spewing organics and dust. Halley’s nucleus holds CO, CO₂ and organic molecules besides water.
Missions
- Vega 1 and 2 (1986)
- Giotto (ESA, 1986): a pass at 596 km
- Suisei and Sakigake (Japan, 1986)
Colony note
Hard to reach, near only for a short time, once every 76 years. A store of ice, ammonia and organic matter: a giant mine on a wandering course.
What probes bring back
- A 76-year orbit; it last passed in 1986 and returns in 2061. Giotto (1986) saw the nucleus from 600 km.
- The nucleus is 15 km, albedo 4 %: darker than coal, coated in organics.