Surface temp.minmeanmax
Surface pressure
20–200 kPa; 70 kPa
Scale height
27 km (17 mi)
Composition by volumeby volume:
6999890000000000000♠89%±2.0% hydrogen (H
2
)
6999100000000000000♠10%±2.0% helium (He)
6997300000000000000♠0.3%±0.1% methane (CH
4
)
6996259999999999999♠0.026%±0.004% ammonia (NH
3
)
6995280000000000000♠0.0028%±0.001% hydrogen deuteride (HD)
6994599999999999999♠0.0006%±0.0002% ethane (C
2
H
6
)
6994400000000000000♠0.0004%±0.0004% water (H
2
O)

Ices:

  • ammonia (NH
    3
    )
  • water (H
    2
    O)
  • ammonium hydrosulfide (NH
    4
    SH)