SpazePeriodic comet
Halley’s Comet
Returns every 76 years. Last seen in 1986, it will be back in 2061. Mark Twain was born and died in Halley years.
- Size
- 14.9 × 8.2 km
- Orbit
- 75.7 years
- Distance from Sun
- 0.6 to 35.2 AU
- Reflects
- 4% of sunlight
- Visited by
- Giotto, Vega 1 and 2, 1986
Can we live on Halley’s Comet?
Air: H₂O 80%, CO 10%. Not breathable: you’d need a suit and your own oxygen.
Ground: Ice and dust under a crust darker than coal.
Atmosphere
- H₂O 80%
- CO 10%
- CO₂ 3%
- CH₄
- NH₃
Measured by Giotto, Vega