Planet g

(×g E ) v esc

(km/s) distance

(A.U.) albedo

(%) temperature

(K) atm. press.

(× Earth's) atm. comp.

Mercury 0.378 4.3 0.387 11.9 100 night,

590725 day 10-15 42% O 2 , 29% Na, 22% H 2 , 6% He, 0.5% K (note that it is essentially a vacuum)

Venus 0.905 10.36 0.723 75 737 92 96.5% CO 2 , 3.5% N 2 ,

0.015% SO 2 , 0.007% Ar, 0.002% H 2 O, 0.002% CO, 0.001% He, 0.001% Ne

Earth 1.000 11.186 1.000 30.6 283 night, 293 day 1.000 78.08% N 2 , 20.95% O 2 ,

0.934% Ar, 0.038% CO 2 ,

H 2 O highly variable ( <1%)

Mars 0.379 5.03 1.524 25.0 184 night, 242 day 0.0040.009 95.32% CO 2 , 2.7% N 2 , 1.6% Ar,

0.13% O 2 , 0.08% CO, 0.021% H 2 O, 0.01% NO

Jupiter 2.530 59.5 5.203 34.3 165 >>1000 89.8% H 2 , 10.2% He,

0.3% CH 4 , 0.026% NH 3 . Clouds made of ammonia ice, water ice, ammonium hydrosulfide

Saturn 1.065 35.5 9.537 34.2 134 >>1000 96.3% H 2 , 3.25% He,

0.45% CH 4 , 0.0125% NH 3 , 0.0110% HD, 0.0007% C 2 H 6 . Clouds made of ammonia ice, water ice, ammonium hydrosulfide

Uranus 0.905 21.3 19.191 30.0 76 >>1000 82.5% H 2 , 15.2% He, 2.3% CH 4 ,

0.0148% HD. Clouds made of ammonia ice, water ice, ammonium hydrosulfide, methane ice

Neptune 1.14 23.5 30.069 29.0 72 >>1000 80.0% H 2 , 19.0% He, 1.5% CH 4 ,

0.0192% HD, 0.0002% C 2 H 6 . Clouds made of ammonia ice, water ice, ammonium hydrosulfide, methane ice