| Period of Revolution, in years || 4·60 || 1·00 | 0·24 | | Velocity, in miles per second || 11·1 ||18·5 | 9·7 | | Eccentricity || 0·0763|| 0·0168| 0·2056| | Aphelion Distance, Perihelion = 1 || 1·157 || 1·034 | 1·517 | | Inclination of Equator to Orbit || (?) || 1°·32´| (?) | | || || d h m | d | | Rotation period || (?) ||27·7·43| 88(?) | | || || | | |ATMOSPHERE, assuming the total mass of the || || | | | atmosphere to be proportional to the mass || || | | | of the planet:-- || || | | | Pressure at the surface in lb. per sq. in. || 0·014 || 0·40 | 1·6 | | " " " in "atmospheres" || 0·0009|| 0·027 | 0·108 | | Level of half surface pressure in miles ||119·0 ||19·6 |10·1 | | Boiling point of water at the surface || || 22°C | 53°C | | || || | | |TEMPERATURE:-- || || | | | Light and heat received from Sun, || || | | | [Symbol] = 1 || 0·13 || 1·00 | 6·67 | | Reciprocal of square-root of distance, || || | | | [Symbol] = 1 || 0·60 || 1·00 | 1·61 | | Equatorial temp. of ideal planet, Absolute || 188 || 312° | 502° | | " " " " Centigrade|| -65 || +39 | +229 | | Average temp. of ideal planet, Absolute || 174 || 290 | 467 | | " " " " Centigrade || -99 || +17 | +194 | | Upper limit under zenith sun, Absolute || 248 || 412 | 664 | | " " " " Centigrade || -25 || +139 | +391 | | Average temp. of equivalent disc, Absolute || 223 || 371 | 598 | | " " " " Centigrade|| -50 || +98 | +325 | | || || | | +--------------------------------------------++--------++-------+-------+